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Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China
G Model ECOIND 2110 No. of Pages 10
Ecological Indicators xxx (2014) xxx–xxx
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Ecological Indicators journal homepage: www.elsevier.com/locate/ecolind
Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China Hualin Xie a, *, Guanrong Yao a , Guiying Liu b a b
Institute of Poyang Lake Eco-Economics, Jiangxi University of Finance and Economics, Nanchang 330013, China School of Economics and Management, Jiangxi Agriculture University, Nanchang 330045, China
A R T I C L E I N F O
A B S T R A C T
Article history: Received 7 May 2014 Received in revised form 1 August 2014 Accepted 26 August 2014
How to assort with the relationship between the urban construction and the maintenance of ecological security is a hot issue during the process of urbanization. The purpose of this study is to identify the key ecological land maintaining ecological security and to put forward some measures for environmental management. Based on the GIS technology, from the view of water security, biodiversity conservation, disaster protection, natural recreation security, and human disturbance, an integrated index is put forward to evaluate the ecological importance of regional space. Then, a GIS-based approach for evaluating ecological importance was created, with Xingguo county of China as a case study. The results show that the area of core eco-space in the study area accounts for 30% of the total area. These areas mainly consist of the core areas of regional river systems, wetlands, nature reserves, forest parks, and scenic spots and the endangered and protected zone of geological hazards. According to the spatial characteristics of ecological importance for different regions, this study proposes some zoning regulations and measures for environmental management. ã 2014 Elsevier Ltd. All rights reserved.
Keywords: Ecological land Ecological security Environmental management Land use management GIS
1. Introduction Land is fundamental to human survival and development, the sources of food and clothing, and the space carrier of human activities (Scholz et al., 2012). Land use is the process of managing and reforming land by human through a series of biological and technical means for certain economic and social purposes (Li, 1996; Vitousek et al., 1997). According to the development goals of land use management, land use types can be divided into cultivated land, construction land and ecological land and so on (see Fig. 1). As seen in Fig. 1, the conversion between different land-use types can bring conflicts between the goals of ecological protection, production, and life. Ecological land is considered as a land-use type with soil and water conservation, sand-fixing, cleaning air, provision of habitat, recreation, and other important ecological functions, and it has drawn increasing attention from many scholars (Xie et al., 2014, 2012; Yu et al., 2009). In contrast with the construction land meeting the need of urban development and the farmland supporting food security, ecological land is defined as the land resources that provide natural ecosystem services and maintain regional ecological security(Rouget et al., 2003; Xie et al.,
* Corresponding author. Tel.: +86 139 7912 1643. E-mail address: [email protected] (H. Xie).
2014). In the past 50 years, some irrational activities of land use have made some ecological space maintaining regional ecosystem health and safety destroyed which leading to a series of ecological and environmental problems such as biodiversity reduction, soil erosion, wetland destruction, and land contamination (Vitousek et al., 1997). The department of land management in China has not paid sufficient attention to land functions that support and maintain the stability of natural and artificial ecosystems (Xie et al., 2014). As the increasing demand for construction land, ecological land in China faces the threat of agricultural exploitation due to the land policy “cultivated land requisition–compensation balance” (Xie et al., 2014). Therefore, an urgent need to evaluate the ecological importance of regional space and to develop some measures to zoning control. This will prevent ecological issues bringing from regional development and construction, guide regional planning for sustainable development, and will carry out ecological conservation and construction. The main objectives are to evaluate the ecological importance of space and to identify the ecological infrastructure (EI) maintaining regional security and healthy of the land. Because ecological infrastructure (EI) can provide sustainable ecosystem services for residents, and it is the rigid restrictions inviolable by urban expansion and land development (Maccagnani et al., 2013). In essence, ecological infrastructure is the natural systems for
http://dx.doi.org/10.1016/j.ecolind.2014.08.042 1470-160X/ ã 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Xie, H., et al., Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China. Ecol. Indicat. (2014), http://dx.doi.org/10.1016/j.ecolind.2014.08.042
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Ecological Land
Arable
Food
Land
Security
Land use
Goals Construction Land
Ecological Security
Urban Development
Fig. 1. Trade-offs of land use and development goal in regional space.
maintaining regional sustainable development. A new comprehensive national land use plan in China (2006–2020) has clearly outlined the requirements for eco-space, which will focus on the overall arrangements for living, life and ecological space, protect the productive land, give priority to the protection of natural eco-spaces, and promote the development of regional ecological civilization. Ecological civilization is a new concept proposed by Hu Jintao and focuses on a list of elements including the right relationship between man and nature. The ecological evaluation based on GIS was firstly proposed by McHarg in 1960s (McHarg, 1969, 1981). In his book “Design with Nature”, McHarg developed the “pastry mode” of land suitability assessment (McHarg, 1969, 1981). Steinitz developed a landscape evaluation model on behalf of conservation planning ideas, namely, how to determine the biodiversity, appearance, cost, nutrition flow, public health, and other conditions (Steinitz, 1990, 1993). Steiner, McHarg’s student, proposed a model of Environmentally Sensitive Area (ESA) in 2000 (Steiner, 2000). In addition, Malczewski developed a multi-criteria method for the land suitability evaluation based on GIS (Malczewski, 2004; Malczewski et al., 2003). Currently, the importance evaluation of ecological land has primarily focus on a single characteristic such as water security, biodiversity conservation, and soil erosion protection. For example, some studies developed a evaluation method to identify new priority areas that best meet desired the targets in combination with any existing protected areas (PAs) (Moilanen and Arponen, 2011). This method, however, is likely to produce portfolios with a large number of small and isolated protected areas (PAs), and such portfolios are less ecologically and economically feasible (Nhancale and Smith, 2011; Smith et al., 2010; Wiersma and Nudds, 2009). Some studies assessed the degree to which macroecological modelling can overcome shortfalls in our knowledge of biodiversity in tropical forests and help identify priority areas for their conservation and management (Mokany et al., 2014). Through identifying the key areas of water security, some scholars analyzed the ecological, social and economic impacts of their protection and restoration (Brouwer and van Ek, 2004). Some studies identified the key areas of soil erosion protection using GIS and Universal Soil Loss Equation (USLE) (Toumi et al., 2013). In addition, some studies on eco-space are more concerned about how to configure the eco-space to maintain the security of regional ecological environment, and mostly for these studies at small watershed scale. Seppelt took the Hunting Creek small watershed in the southern United States as the experimental area and have designed a spatial configuration scheme of land use and maximum standard amount of chemical fertilizer distribution
to control pollution caused by fertilizers using GIS and spatial differentiation model (Seppelt and Voinov, 2002). For the importance evaluation of regional ecological space, Chinese scholars have mainly focused on ecological sensitivity and ecological suitability (He et al., 2008; Yu et al., 2008). Yu constructed a comprehensive evaluation model for ecological sensitivity based on GIS, which includes ecological protection sensitivity, ecological buffer sensitivity, landscape visual sensitivity, and ecological security sensitivity (Yu et al., 2008). The methods of ecological assessment based on GIS mainly included overlapping factors method, logical combination method (Yan et al., 2009), ecological fitness model (Ouyang et al., 1996), and minimum cumulative resistance model (Liu et al., 2010). The current studies on ecological evaluation mainly focused on the aspects of natural ecology, and the results did not reflect the spatial characteristics of regional ecosystem and maintaining ecological security. The ecological importance evaluation of regional space is to emphasize on the harmonious development between production space, living space, and ecological space, to focus on the symbiosis between man and other organisms, and to maintain the natural foundation of urban development using applied principles in ecology. Based on the analysis of ecological characteristics, ecological importance evaluation is to explore the spatial distribution of regional ecological importance and to provide some measures for preventing ecological security issues from the regional development and construction. The main purposes of this study are (1) to construct an integrated index at spatial scale to assess the importance of regional space maintaining water security, biodiversity conservation, disaster avoidance and protection, natural recreation, (2) to establish an GIS-based approach to identify the key space maintaining ecological security, (3) to propose some zoning regulations and measures for environmental management. 2. Materials and methods 2.1. Study area The study area (115 010 –115 510 E, 26 030 –26 410 N) is Xingguo county in Jiangxi province of China (Fig. 2), which is located in the mid-southern areas and lies to the North of Ganzhou City, at the headwaters of Pinggu River. It is surrounded by the mountains in the east, north, and west. There is a valley basin centered in the county in the south-central, mostly lowmountains and hills. In 2005, the GDP of Xingguo totaled 3.32 billion Yuan. The proportion of three industrial structures is 39.3:31.3: 29.4, and the rural per capita net income is 2376 Yuan in 2005. The study area covers an area of 15.5 km2, and the resident population was 121,000.
Please cite this article in press as: Xie, H., et al., Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China. Ecol. Indicat. (2014), http://dx.doi.org/10.1016/j.ecolind.2014.08.042
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Fig. 2. Study area.
The county belongs to the subtropical southeast monsoon climate, with an annual average temperature of 18.9 C, an extreme maximum temperature of 39.9 C, and an extreme minimum temperature of under 6.3 C. The annual average frost-free period amounts to 248 days. The average annual rainfall is 1516 mm, which is concentrated in April and June, with rainfall from April to June accounts for 48.5% of annual precipitation. 2.2. Data The data of land use, ecosystem type, DEM and NDVI in this study were derived from the National Ecological Environment Decade Change Assessment Database System. The zoning map of Drinking Water Conservation Areas, the map of nature reserves, forest parks, geological parks and scenic areas, and the basic geographic information data of Xingguo county derived from Data Center for Resources and Environmental Sciences of the Chinese Academy of Sciences. Climatic data were derived from the China Meteorological Data Sharing Service System. The soil data in the study were derived from the Second National Soil Survey of China, and the related physicochemical properties and types of soil from the database were collected and analyzed by the Institute of Soil Science at the Chinese Academy of Sciences. Before processing operations, all graphical data were first preprocessing by projection transformation, using the ALBERS equal-area conic projection (Krasovsky_1940_Albers). Through resampling, the spatial resolution is converted to the raster of 50m 50 m. The two operations are realized, respectively, by projecting and resampling, to make sure the projection and precision of the graphics output uniform.
2.3. Methods 2.3.1. General idea of ecological importance evaluation According to the related studies (Allan and Peterson, 2002; Yu et al., 2009; Zagas et al., 2011), the spaces maintaining ecological security mainly consist of the areas for the maintenance of water security, biodiversity protection, disaster avoidance, and recreational area protection. In addition to this, we should consider the influence of human disturbance. Therefore, the general idea of ecological importance evaluation is shown in Fig. 3. 2.3.2. Principals of index selection As a measure of the index system for ecological importance evaluation, not only to be followed by the universal principles including objectivity, integrity and effectiveness, it should also be considered from the following three aspects. (1) Service for the optimization of ecological landscape pattern
The main purpose of ecological importance evaluation of regional space is to provide a basis for the optimization of ecological landscape pattern. Therefore, the evaluation indexes should be able to have spatial characteristics. The evaluation results should be combined with GIS into every land use patches and try to achieve the positioning and quantitative evaluation for ecological landscape, which can provide a theoretical basis for subsequent environmental planning and design. (2) Reflecting the problems of regional eco-security
Please cite this article in press as: Xie, H., et al., Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China. Ecol. Indicat. (2014), http://dx.doi.org/10.1016/j.ecolind.2014.08.042
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Fig. 3. General idea of ecological importance evaluation.
Spatial pattern of regional land use is the outcome caused by human and natural factors. Major eco-environmental problems in the study area include the protection of water and soil resources, biodiversity conservation, and disaster protection and so on. Therefore, considering the accessibility of data, the index system of ecological importance evaluation should be constructed from the eco-problems and by using evaluation methods of ecological sensitivity, with RS and GIS techniques. (3) Operability
The selected indexes should be operational for data collection. The data for selected indexes have some statistical basis, comparability, and testability. The data for selected indexes can be accurately collected, and to be able to quantify the extent possible. 2.3.3. Frame of index system for ecological importance evaluation According to the meaning of ecological importance evaluation and the above principals of indexes selection, a three-level index system has been established to evaluate the ecological importance of regional space (see Fig. 4). The first level of index system is the object layer, namely, the integrative index of ecological importance. The second level is the item layer, namely, the factors influencing the importance of eco-space. The third level is the index layer, which is the individual indexes measuring the influencing factors. 2.3.4. Grading criteria of indexes of ecological importance evaluation Different types of indexes have varied impacts and contributions on ecological importance. After the discussions, amendments and comprehensive evaluation from the dozen experts in relevant disciplines, the grade level of each single factor was determined. Each grade level (extremely important, moderately important, generally important, or not important) is assigned to 7, 5, 3, and 1, respectively. The grading criteria and assigned scores of each index for ecological importance evaluation are listed in Table 1.
2.3.5. Computation of indexes 2.3.5.1. Importance of water security. Water system is one of the important spaces maintaining regional ecosystem health. Identifying the key spaces maintaining water security is to start from the entire watershed, leaving the spaces of wetlands, and river buffers, which can meet the natural vent of flood. At the same time, it also includes the spaces of water sources protection and water storage. Therefore, four indexes have been selected to evaluate the importance of this type of space: the distance to a river or lake, the type of flood storage areas, the type of water source protection areas, and the importance of water storage. With the spatial distributions of rivers and lakes, the index of the buffering distance to a river or lake can be obtained using the module of straight-line distance function in software ArcGIS9.3. The index of the type of flood conditioning storage areas can be obtained from the digitized zoning maps of land use, wetlands, and detention basins. The index of the type of water source protection areas can be obtained from the digitized zoning map of water source protection areas. The index of the importance of water storage can be obtained from the quantity of the water storage of different ecosystems. The formula of the quantity of water storage from different ecosystems is as follows: Q ¼ A J R0 Rg
J ¼ J0 K
(1)
where Q is the increasing quantity of water storage from different ecosystems such as forest or grass ecosystem by the comparison with bare land, A is the area of ecosystem, J is the annual rainfall runoff (P > 20 mm) of average years in the study area, J0 is the annual total rainfall of average years in the study area, K is the proportion of rainfall runoff on total rainfall, R0 is the effectiveness coefficient of bare land reducing runoff. Rg is the effectiveness coefficient of other ecosystems reducing runoff. In this study, the values of K and R refer to the relevant studies (Zhao et al., 2004).Using Formula (1) and
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Distance index to a river or lake Type index of flood storage areas
Water security
Type index of water source protection area Importance index for water storage Habitat sensitivity index Biodiversity
Vegetation coverage
conservation Habitat quality index Integrative Sensitivity index of geological hazards
index of
Disaster protection
Importance index of soil conservation
ecological Importance index of land desertification protection
importance
Natural recreation
Suitability index of natural recreation
Strength index of main roads Human disturbance
Strength index of building land of urban Population congregation index
Fig. 4. Index system for evaluating ecological importance of regional space.
after standardization, we calculated the importance index of water storage for each spatial unit using the module of spatial analysis in software ArcGIS9.3. And then using the standard deviation (1 SD) classification, the importance index of water storage is to divide into four rankings (extremely important, moderately important, generally important, and not important). We used a disjunction function to calculate the ecological importance index of the space maintaining water security (EIIw) for each grid, where the four indexes represent four aspects of maintaining regional water security. The equation is as follows: EIIw ¼ Maxðs1 ; s2 ; s3 ; s4 Þ
(2)
where EIIw represents the ecological importance index of the space maintaining water security, s1 is the index of the distance to a river
or lake, s2 is the index of the type of flood conditioning storage areas, s3 is the index of the type of water source protection areas, and s4 is the index of the importance for water storage. Using Eq. (2), we calculated the ecological importance index of the space maintaining water security for each grid using software ArcGIS9.3. Finally, using the raking standards in Table 1, we obtained the spatial grade map of water security importance. 2.3.5.2. Importance of biodiversity conservation. Biodiversity conservation indexes mainly refer to the influencing factors maintaining regional biodiversity conservation. In this study, three indexes habitat scarcity, vegetation coverage, and habitat quality have been selected to evaluate the ecological importance of the space maintaining biodiversity.
Table 1 Grading criteria and assigned scores for the indexes of the ecological importance evaluation. Index
Extremely important
Moderately important
Generally important
Not important
Distance index to a river or lake (s1) Type index of flood storage areas (s2)
<50 m Wetland areas
50–100 m Core areas of detention basins
>150 m Other areas
Type index of water source protection area (s3) Importance index for water storage (s4) Habitat sensitivity index (s5) Vegetation coverage (s6) Habitat quality index (s7) Sensitivity index of geological hazards (s8) Importance index of soil conservation (s9)
First-grade protection zones of water resources 0.6–1 0.6–1 >0.6 0.6–1 First-grade protection zones of water resources Extremely sensitive
Second-grade protection zones of water resources 0.4–0.6 0.4–0.6 0.4–0.6 0.4–0.6 Second-grade protection zones of water resources Highly sensitive
100–150 m Non-core areas of detention basins Quasi-watershed protection zone 0.2–0.4 0.2–0.4 0.2–0.4 0.2–0.4 Quasi-watershed protection zone Moderately sensitive
Importance index of land desertification protection (s10) Suitability index of natural recreation (s11) Strength index of main roads (s12) Strength index of building land of urban (s13) Population congregation index (s14) Assigned score
Extremely sensitive
Highly sensitive
Moderately sensitive
Extremely suitable
Moderately suitable
Generally suitable
Mildly sensitive/not sensitive Mildly sensitive/not sensitive Not suitable
>500 m >1000 m
200–500 m 500–1000 m
100–200 m 200–500 m
<100 m <200 m
<300 7
300–400 5
400–500 3
>500 1
None 0–0.2 0–0.2 <0.2 0–0.2 None
Please cite this article in press as: Xie, H., et al., Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China. Ecol. Indicat. (2014), http://dx.doi.org/10.1016/j.ecolind.2014.08.042
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According to the equivalent quantum of biodiversity service for different land-use types and the protection grades of different regions, we developed a habitat scarcity index (HSI). The equation for the habitat scarcity index (HSI) is as follows: HSI ¼ nl m
(3)
where, HSI is the scarcity index of habitats, nl is the equivalent quantum of biodiversity service for land use type l,m is the corrected value of the protection ranking. For the nature reserves, parks, scenic areas, and other land-use types, m are assigned values of to 1.75, 1.5, 1.25, and 1, respectively. The index vegetation type can be obtained from the digitized maps of ecosystem type. The index of vegetation coverage (VC) can be obtained from the map of Normalized Difference Vegetation Index (NDVI). The index of the habitat quality reflects the level of biodiversity. The formula of habitat quality index (HQI) is as follows: $ !% Dzxj z þ k HQIxj ¼ Hj 1 Dzxj
Dxj ¼
XY r
XR r¼1
y¼1
irxy ¼ 1
dxy drmax
!
wr
PR
r¼1
wr
ry irxy bx Sjr
(4)
where HQIxj is the habitat quality of the grid x for the land use type j, Hj represents the habitat suitability of land use type j, Dxj refers to the habitat stress level of the grid x for the land use type j. irxy refers to the stress role of the factor r of grid y on the grid x, dxy refers to a straight line between grid x and grid y. drmax represents the maximum effect distance of the stress factor r. wr is the weight of stress factor, which represents the relative damage of a stress factor on all habitats. bx represents the level of accessibility grid x. Sjr represents the sensitivity of the stress factor r on the land use type j. k is the constant of half-saturation. When the formula z 1 ðDzxj =Dzxj þ k Þ is equal to 0.5, the k value is equal to D value. The stress factors considered in this study include natural factors (i.e., natural disaster, landslide and mudslides) and human factors (i.e., road, urban settlements, and farmland). The spatial
distribution data of different stress factors come from the topographic map and the land use map in the study area. We used a product method to calculate the ecological importance index of the space maintaining biodiversity (EIIb) for each grid, where the three indexes represent three aspects of maintaining regional biodiversity. The equation is as follows: vffiffiffiffiffiffiffiffiffiffi u n Y u n (5) EIIb ¼ t Si i¼1
where EIIb represents the ecological importance index of the space maintaining biodiversity, Si represents the assigned score of evaluation indicator i, which is obtained using the raking standards in Table 2. In the importance evaluation of biodiversity conservation, evaluation indicators include habitat scarcity index, vegetation coverage and habitat quality index. Using Eq. (5), we calculated the ecological importance index of the space maintaining biodiversity for each grid using software ArcGIS9.3. Finally, we can obtain a spatial grade map of biodiversity conservation importance using the raking standards in Table 1. 2.3.5.3. Importance of disaster protection. Disaster protection evaluation is to mainly identify the ecological space of disaster risk aversion and disaster protection. In this study, three indexes sensitivity of geological hazard zones (s8), importance of soil conservation (s9), and importance of land desertification protection (s10) are selected to evaluate the importance space of disaster protection. The spatial distribution of geo-disaster danger area can be obtained from the digitized map of sensitivity analysis for landslide and debris flow. The index sensitivity of geological hazard zones is obtained from sensitivity evaluation of the geological hazards in the study area including landslides and debris flows. Using the universal soil loss equation (USLE), we evaluated the soil erosion sensitivity in the study area. The universal soil loss equation (USLE) includes five indexes rainfall and runoff (R), soil erodibility (K), slope and slope length and crop/vegetation and management (C). We also evaluated land desertification sensitivity using four indexes humidity, the days with wind speed greater than 6 m/s in winter and spring, soil texture and vegetation coverage in winter and spring. The evaluation method for soil erosion sensitivity and land desertification sensitivity refers to the related studies (Xie, 2008; Yan et al., 2009).
Table 2 Results of the evaluation of ecological importance in Xingguo county. Evaluation factors
Importance ranking
Areas (hm2 align="center")
Percentage of total area (%)
Cumulative percentage of total area (%)
Water security
Extremely important Moderately important Generally important Not important
67987.98 127930.95 55904.22 69178.86
21.18 39.85 17.42 21.55
21.18 61.03 78.45 100.00
Biodiversity conservation
Extremely important Moderately important Generally important Not important
26190.72 154256.49 74277.36 66277.44
8.16 48.05 23.14 20.65
8.16 56.21 79.35 100.00
Extremely important Moderately important Generally important Not important
31997.52 130165.92 81725.85 77112.72
9.97 40.55 25.46 24.02
9.97 50.52 75.98 100.00
Extremely important Moderately important Generally important Not important
3687.84 8942.49 116311.32 192048.48
1.15 2.79 36.23 59.83
1.15 3.93 40.17 100.00
align="left" Disaster protection align="left"
align="left" Natural recreation
Please cite this article in press as: Xie, H., et al., Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China. Ecol. Indicat. (2014), http://dx.doi.org/10.1016/j.ecolind.2014.08.042
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We used a disjunction operation to calculate the ecological importance index of the space protecting disasters for each grid. The equation is as follows: EIId ¼ Maxðs8 ; s9 ; s10 Þ
(6)
where EIId represents the ecological importance index of the space protecting disasters, s8 is the sensitivity index of geological hazard zones, s9 is the importance index of soil conservation, and s10 is the importance for land desertification protection. 2.3.5.4. Importance of natural recreation security. Ecological land not only can preserve soil and water conservation, provide habitats for the species and protect disaster, but also has the function of natural recreations. In this study, we identified the important space maintaining natural recreation security with a natural recreation suitability index. The ecosystems with high entertainment value are important for residents to enjoy natural recreation activities. Based on land use type and the equivalent quantum of entertainment service established by previous studies (Xie et al., 2003; Yan et al., 2009), we corrected the equivalent quantum of recreation service. The formula of the natural recreation suitability index is given as follow: EIIr ¼ pl q
(7)
where EIIr is the ecological importance index of space providing natural recreation, pl is the equivalent quantum of entertainment service for land use type l, and q is the corrected recreation ranking value. Parks, scenic areas, nature reserves and other lands are assigned the values of 1.75, 1.5, 1.25, and 1, respectively. Using the Eq. (4), we calculated the natural recreation suitability index for each spatial unit using the module of spatial analysis in software ArcGIS9.3. And then using the standard deviation (1 SD) classification, the natural recreation suitability is to divide into four rankings (extremely suitable, moderately suitable, generally suitable, and not suitable). 2.3.5.5. Influence of human disturbance. Human disturbance evaluation mainly reflects the degree of interference of human activities on ecological space, and its influence is inversely proportional with ecological importance. In other words, the higher the human interference coefficient is, the lower the ecological importance of the space will be. In this study, three indexes strength of main roads, strength of construction land of urban and town, and population congregation are selected to evaluate the degree of interference of human activities. With the spatial distributions of the road and construction land of urban and town, the two indexes of the strength of main roads and the strength of building land of urban and town can be obtained using the module of straight-line distance function in software ArcGIS9.3. These two indexes reflect the impacts of transportation and construction land on eco-environment and the attenuation characteristics with distance. The index of the population aggregation reflects the degree of human disturbance on ecological land. The larger population aggregation index and the greater the degree of interference with the ecological land is, the lower the ecological importance of the space will be. The formula of population aggregation index (PAI) is as follows: PAIj ¼
pj nl
(8)
where PAIj is the value of population aggregation index of the residential area j, pj is the total population of the demographic areas j, n is the total number settlements in the j-th statistical area. l Is a weighting value, which is an inverse distance weighted value by the distance from the urban or town centers and roads. Based on
7
the above formula, the spatial distribution of population aggregation index can be interpolated by Kriging model. The integrated index of human disturbance was obtained by the same method of ecological importance index of the space maintaining biodiversity (EIIb). Using Formula (8), we calculated the integrated index of human disturbance (EIIh) for each grid using software ArcGIS9.3. Finally, we can obtain a spatial grade map of human disturbance influence using the raking standards in Table 1. 2.3.6. Integrated evaluation of ecological importance Due to the different eco-spaces maintaining ecological security are independent, in order to highlight the importance status of ecosystem maintaining ecological security, a comprehensive evaluation of eco-space importance is conducted by using the maximum value method. Based on the evaluation of eco-space importance, we considerd the influence of human disturbance. Its formula of the ecological importance of integrated evaluation for space (EIIS) is as follows: EIIS ¼ MaxðEIIw ; EIIb ; EIId ; EIIr ÞIEIIh
(9)
where EIIS is the ecological importance of integrated evaluation for regional space, EIIw is the ecological importance index of the space maintaining water security, EIIb is the ecological importance index of the space maintaining biodiversity conservation, EIId is the ecological importance index of the space maintaining disaster protection security, EIIr is the ecological importance index of the space providing natural recreation, EIIh is the integrated index of human disturbance. 3. Results and discussion The results of importance evaluation for the space maintaining single ecological security in Xingguo county are listed Table 2 and shown in Fig. 5. For the importance of water security, the area of extremely important is 67,987.98 hm2, accounting for 21% of the total area (see Table 2). These areas are extremely valuable for the maintenance of local water security, including water resource conservation and flood regulation and storage. Fig. 5(a) shows that the key spaces maintaining water security mainly consist of woodlands and regional river systems, which located in the northern and southern mountains in the study area. There are good quality and significant functions of water conservation for the woodlands in these areas, and the lake-river system in these areas plays a vital role in flood control. For biodiversity conservation, the results of importance evaluation are shown in Fig. 5(b) and Table 2. From Table 2, the area of extremely important for maintaining biodiversity conservation accounts for 8% of the total area. These areas mainly consist of the core area of Mountain Nature Reserve (see Fig. 5(b)). The sunny and half-sunny slopes of these areas contain deciduous broad-leaved forest, mainly consisting of fir and pine, which is the core habitat of most biological species. Although there is a small key area for biodiversity conservation, it mostly covers the habitats of regionally rare species and key species. Therefore, it is important for maintaining biodiversity security to identify the ecological processes of biodiversity conservation and to build an urban and rural local continuous habitation and bio-corridor system. The area of moderately important for maintaining biodiversity is 154,256.49 hm2, which mainly consist of woodlands, which acts as the buffer for native biological species and locate in the mountains. The area of extremely important, moderately important, and important for maintaining biodiversity makes up close to 60% of the total area.
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Fig. 5. Results of evaluation of ecological importance for single security in Xingguo county.
As can be seen from Fig. 5(c) and Table 3, for disaster avoidance and protection, the area of extremely important is 31,997.52 hm2, accounting for 10% of the total area. These areas are the extremely dangerous areas due to geological hazard such as landslide and mudflow. Considering the security of residents, construction development should be avoided in these areas. Meanwhile, the region is characterized by sparse vegetation, thick loess cover, and severe soil erosion. Large areas prone to geomorphic hazards, such as landslides, mudslides, and soil erosion, should be regarded as the emphasis region of evasion and protection. The area of moderately important is 130,165.92 hm2, accounting for 40% of the total area. These areas of extremely important, moderately important, and important should be vigorously for planting trees and grass, reforestation and to avoid large-scale development and construction activities. From Fig. 5(d) and Table 2, for natural recreation importance, the area of extreme importance and moderate importance accounts for 4% of the total area. These areas primarily consist of the core areas of forest parks, scenic spots and river systems. These areas have high values for natural recreation due to land use types are wetlands and woodlands. As the growing demands for outdoor recreation, wetlands and forests have become the open recreational spaces for the residents. For the sustainable development in these areas, some measures should be put forward, including controlling the capacity for tourists, avoiding the over
exploitation from tourism, and protecting the natural landscape with high recreational value. According to above results of importance evaluation for the spaces maintaining water security, biodiversity protection, disaster avoidance, and recreational area protection, we then considered the impacts of human disturbance and obtained the integrated result of evaluation eco-space importance in Xingguo county (see Table 3 and Fig. 6). From Fig. 6, we can see that the extremely important ecological land is mountains and mainly located in the north and east of study area. These areas mainly consist of the core areas of river systems, wetlands, nature reserves and forest land, and the protection zones of soil erosion, which are the ecological barrier for maintaining homeland security. There are high vegetation cover, rich biodiversity, and weak resistance to natural disasters in the areas of extremely important ecological land, where man-made disturbances can not afford. The area of the extremely important ecological land is 96,025.68 hm2, accounting for 30% of the total area, which are the ecological “red line” for the maintenance of regional eco-security and should be strictly protected and included in prohibited exploitation zone, and prohibited any exploitation and construction activities. The concept of the ecological “red line” is established to provide more space provided for nature to restore itself. Ecological “red line” requires all regions to optimize, prioritize, restrict, or prohibit their industrial development
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Table 3 Integrated evaluation result of the eco-space importance in Xingguo county. Importance ranking
Areas (hm2 align="left")
Percentage of total area (%)
Cumulative percentage of total area (%)
Extremely important Moderately important Generally important Not important
96025.68 112527.45 69615.45 42833.43
29.91 35.06 21.69 13.34
29.91 64.97 86.66 100.00
according to their defined nature. The directions of ecological protection and construction in these areas are focused on the ecological conservation, the improvement of water conservation function, the construction of ecological projects in forestry, the purification for water and the protection of biodiversity. The areas of moderately important ecological land are 112,527.45 hm2, accounting for 35% of the total area. These areas are located in the buffer zone of the extremely important ecological land, including the ecological buffer zones of the river systems and the core area of biodiversity conservation (see Fig. 6). There are fragile eco-environment, weak self-regulation, and poor stability in these areas, where serious ecological degradation may occur under the man-made or natural disturbances. Therefore, they are the key areas of ecological risk prevention. These areas are designated as the restricted development zones, where limiting the activities of development and construction. The regulations in the moderately important eco-space include strengthening the conservation for the existing vegetations, prohibiting the activities of damaging eco-environment such as deforestation and other
unauthorized reclamations, and effective recovery or reconstruction for the destroyed vegetations. The area of moderately important ecological land is 69,615.45 hm2, accounting for 21% of the total area. These areas are mainly located in the southern regions of study area, including the transition zone of moderately sensitive area, the main catchment areas of surface runoff and the secondary areas of ecological buffer zone along rivers or lakes (see Fig. 6). From the start of protecting natural ecosystems, ecological regulations in these regions include adjusting the structure and layout of industrial, formatting the green industry with small environmental damage and high added value and building the ecological corridors and the eco-industrial development zone maintaining ecological security. The area of not important eco-space is 42,833.43 hm2, only accounting for 13% of the total area, which are mainly built-up areas and arable land and mainly responsible for human habitation and agricultural production. Therefore, the regulations in these areas include the reasonable controls of population size, the
Fig. 6. Integrated evaluation of ecological importance of space in Xingguo county.
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adjustments of industrial structure, and the development of ecoindustries. As one of the important theories in ecology, niche is widely used in the natural and socio-economic systems in recent years. The meaning of niche theory is constantly expanding, and gradually developed from species niche to biodiversity conservation niche and urban niche and so on (Costa et al., 2010). The spatial evaluation of ecological important must also consider the land demands from socio-economic development and urbanization in the future. Therefore, considering the scenarios of economic development and the effects from land-use in the surrounding area, some scenarios simulations for the ecological importance of regional space is the research direction using ecological bit cellular automata (CA) model in the future. 4. Conclusions The method of evaluating eco-space importance in this study is better than the existing ones. Firstly, the evaluation method developed in this study is based on the demands of maintaining regional eco-security. Secondly, compared to current studies, it has considered many factors including water security, biodiversity conservation, disaster avoidance and protection, natural recreation and human disturb. Thirdly, a GIS-based approach can propose the results of the explicit and feasible multi-scenarios, which facilitates the effective management of ecological space. The results show the spatial characteristics of eco-space for maintaining the water security, biodiversity, disaster protection and recreation, which indicate that the spatial method for ecological importance evaluation in this study is feasible. The area of extremely important eco-space accounts for 30% of the total area, which is the endangered and protected zones of geological hazards and the core areas of regional river systems, wetlands, nature reserves, forest parks, and scenic spots. These spaces are the bottom line for maintaining ecological security. For the spatial characteristics of ecological importance in different regions, some zoning regulations and measures should be proposed for environmental management. Acknowledgements This study was supported by the National Natural Science Foundation of China (No. 41361111 and No. 41461019), the Fok Ying Tung Foundation (No. 141084), the Natural Science Foundation of Jiangxi Province (No. 20142BAB203028), the Technology Foundation of Jiangxi Education Department of China (No. KJLD14033 and No. GJJ14346), and the Social Science Foundation of Jiangxi Province (No. 13GL05). References Allan, I., Peterson, J., 2002. Spatial modeling in decision support for land- use planning: a demonstration from the Lal Lal catchment, Victoria, Australia. Aust. Geog. Stud. 40, 84–92. Brouwer, R., van Ek, R., 2004. Integrated ecological: economic and social impact assessment of alternative flood control policies in the Netherlands. Ecol. Econ. 50, 1–21. Costa, G.C., Nogueira, C., Machado, R.B., 2010. Sampling bias and the use of ecological niche modeling in conservation planning: a field evaluation in a biodiversity hotspot. Biodivers. Conserv. 17, 883–899. He, X., Xue, P., Zhang, N., 2008. Evaluation of ecological suitability in Changping district of Beijing city. Acta Scientiarum Naturalium UN. 41, 50–56.
Li, X.B., 1996. Core of global environmental change research: frontier in land use and coverage change. Acta Geog. Sin. 51, 553–558. Liu, X., Su, J., Zhang, L., 2010. Research on applying minim a l cumulative resistance model in urban land ecological suitability assessment: as an example of Xiamen city. Acta Ecol. Sin. 30, 421–428. Maccagnani, B., Ferrari, R., Pozzati, M., 2013. Ecological infrastructure management for enhanced pollination and targeted precision biocontrol: the bicopoll project. Bull. Insectol. 66, 26. Malczewski, J., 2004. GIS-based land-use suitability analysis: a critical overview. Prog. Plann. 62, 3–65. Malczewski, J., Chapman, T., Flegel, C., Walters, D., Shrubsole, D., Healy, M.A., 2003. GIS – multicriteria evaluation with ordered weighted averaging (OWA): case study of developing watershed management strategies. Environ. Plann. A 35, 1769–1784. McHarg, I., 1969. Design with Nature. Natural History Press, New York. McHarg, I., 1981. Human planning at Pennsylvania. Landscape Plann. 8, 109–120. Moilanen, A., Arponen, A., 2011. Administrative regions in conservation: balancing local priorities with regional to global preferences in spatial planning. Biol. Conserv. 144, 1719–1725. Mokany, K., Westcott, D.A., Prasad, S., Ford, A.J., Metcalfe, D.J., 2014. Identifying priority areas for conservation and management in diverse tropical forests. PLoS One 9 doi:http://dx.doi.org/10.1371/journal.pone.0089084. Nhancale, B.A., Smith, R.J., 2011. The influence of planning unit characteristics on the efficiency and spatial pattern of systematic conservation planning assessments. Biodivers. Conserv. 20, 1821–1835. Ouyang, Z., Wang, R., Fu, G., 1996. Ecological niche suitability model and its application in land suitability assessment. Acta Ecol. Sin. 16, 113–120. Rouget, M., Cowling, R.M., Pressey, R.L., Richardson, D.M., 2003. Identifying spatial components of ecological and evolutionary processes for regional conservation planning in the Cape Floristic Region South Africa. Divers. Distrib. 9, 191–210. Scholz, M., Hedmark, A., Hartley, W., 2012. Recent advances in sustainable multifunctional land and urban management in Europe: a review. J. Environ. Plann. Manag. 55, 833–854. Seppelt, R., Voinov, A., 2002. Optimization methodology for land use patterns using spatially explicit landscape models. Ecol. Modell. 125–142. Smith, R.J., Di Minin, E., Linke, S., Segan, D.B., Possingham, H.P., 2010. An approach for ensuring minimum protected area size in systematic conservation planning. Biol. Conserv. 143, 2525–2531. Steiner, F., 2000. A watershed at a watershed: the potential for environmentally sensitive area protection in the upper San Pedro Srainage Basin (Mexico and USA). Landscape Urban Plann. 129–148. Steinitz, C., 1990. A framework for theory applicable to the education of landscape architects and other environmental design professionals. Landscape J. 136–143. Steinitz, C., 1993. A framework for theory and practice in landscape planning. GIS Eur. 42–45. Toumi, S., Meddi, M., Mahe, G., Brou, Y.T., 2013. Remote sensing and GIS applied to the mapping of soil loss by erosion in the Wadi Mina catchment. Hydrol. Sci. J. – J. Sci. Hydrol. 58, 1542–1558. Vitousek, P.M., Mooney, H.A., Lubchenco, J., Melillo, J.M., 1997. Human domination of Earth’s ecosystems. Science 277, 494–499. Wiersma, Y.F., Nudds, T.D., 2009. Efficiency and effectiveness in representative reserve design in Canada: the contribution of existing protected areas. Biol. Conserv. 142, 1639–1646. Xie, G.D., Lu, C.X., Leng, Y.F., Zheng, D., Li, S.C., 2003. Ecological assets valuation of the Tibetan Plateau. J. Nat. Resour. 18, 189–196. Xie, H., 2008. GIS-based land-use eco-security evaluation in typical agro-pastoral zone. Chin. J. Ecol. 27, 135–139. Xie, H., Liu, Z., Wang, P., Liu, G., Lu, F., 2014. Exploring the mechanisms of ecological land change based on the spatial autoregressive model: a case study of the Poyang lake eco-economic zone, China. Int. J. Environ. Res. Public Health 11, 583–599. Xie, H.L., Kung, C.C., Zhang, Y.T., Li, X.B., 2012. Simulation of regionally ecological land based on a cellular automation model: a case study of Beijing, China. Int. J. Environ. Res. Public Health 9, 2986–3001. Yan, L., Xu, X.G., Xie, Z.L., 2009. Integrated assessment on ecological sensitivity for Beijing. Acta Ecol. Sin. 29, 3117–3125. Yu, K.J., Qiao, Q., Li, D.H., 2009. Ecological land use in three towns of eastern Beijing: a case study based on landscape security pattern analysis. Chin. J. Appl. Ecol. 20, 1932–1939. Yu, S., Wang, Y., Li, J., 2008. Appraisal of eco-sensitivity on small sized industrial city in Northern China: set the Shahe city as an example. J. Fudan Univ.: Nat. Sci. 47, 501–508. Zagas, T.D., Raptis, D.I., Zagas, D.T., 2011. Identifying and mapping the protective forests of southeast Mt. Olympus as a tool for sustainable ecological and silvicultural planning, in a multi-purpose forest management framework. Ecol. Eng. 37, 286–293. Zhao, T., Ouyang, Z., Zhang, H., 2004. Forest ecosystem services and their valuation in China. J. Nat. Resour. 19, 480–491.
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Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China Hualin Xie a, *, Guanrong Yao a , Guiying Liu b a b
Institute of Poyang Lake Eco-Economics, Jiangxi University of Finance and Economics, Nanchang 330013, China School of Economics and Management, Jiangxi Agriculture University, Nanchang 330045, China
A R T I C L E I N F O
A B S T R A C T
Article history: Received 7 May 2014 Received in revised form 1 August 2014 Accepted 26 August 2014
How to assort with the relationship between the urban construction and the maintenance of ecological security is a hot issue during the process of urbanization. The purpose of this study is to identify the key ecological land maintaining ecological security and to put forward some measures for environmental management. Based on the GIS technology, from the view of water security, biodiversity conservation, disaster protection, natural recreation security, and human disturbance, an integrated index is put forward to evaluate the ecological importance of regional space. Then, a GIS-based approach for evaluating ecological importance was created, with Xingguo county of China as a case study. The results show that the area of core eco-space in the study area accounts for 30% of the total area. These areas mainly consist of the core areas of regional river systems, wetlands, nature reserves, forest parks, and scenic spots and the endangered and protected zone of geological hazards. According to the spatial characteristics of ecological importance for different regions, this study proposes some zoning regulations and measures for environmental management. ã 2014 Elsevier Ltd. All rights reserved.
Keywords: Ecological land Ecological security Environmental management Land use management GIS
1. Introduction Land is fundamental to human survival and development, the sources of food and clothing, and the space carrier of human activities (Scholz et al., 2012). Land use is the process of managing and reforming land by human through a series of biological and technical means for certain economic and social purposes (Li, 1996; Vitousek et al., 1997). According to the development goals of land use management, land use types can be divided into cultivated land, construction land and ecological land and so on (see Fig. 1). As seen in Fig. 1, the conversion between different land-use types can bring conflicts between the goals of ecological protection, production, and life. Ecological land is considered as a land-use type with soil and water conservation, sand-fixing, cleaning air, provision of habitat, recreation, and other important ecological functions, and it has drawn increasing attention from many scholars (Xie et al., 2014, 2012; Yu et al., 2009). In contrast with the construction land meeting the need of urban development and the farmland supporting food security, ecological land is defined as the land resources that provide natural ecosystem services and maintain regional ecological security(Rouget et al., 2003; Xie et al.,
* Corresponding author. Tel.: +86 139 7912 1643. E-mail address: [email protected] (H. Xie).
2014). In the past 50 years, some irrational activities of land use have made some ecological space maintaining regional ecosystem health and safety destroyed which leading to a series of ecological and environmental problems such as biodiversity reduction, soil erosion, wetland destruction, and land contamination (Vitousek et al., 1997). The department of land management in China has not paid sufficient attention to land functions that support and maintain the stability of natural and artificial ecosystems (Xie et al., 2014). As the increasing demand for construction land, ecological land in China faces the threat of agricultural exploitation due to the land policy “cultivated land requisition–compensation balance” (Xie et al., 2014). Therefore, an urgent need to evaluate the ecological importance of regional space and to develop some measures to zoning control. This will prevent ecological issues bringing from regional development and construction, guide regional planning for sustainable development, and will carry out ecological conservation and construction. The main objectives are to evaluate the ecological importance of space and to identify the ecological infrastructure (EI) maintaining regional security and healthy of the land. Because ecological infrastructure (EI) can provide sustainable ecosystem services for residents, and it is the rigid restrictions inviolable by urban expansion and land development (Maccagnani et al., 2013). In essence, ecological infrastructure is the natural systems for
http://dx.doi.org/10.1016/j.ecolind.2014.08.042 1470-160X/ ã 2014 Elsevier Ltd. All rights reserved.
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Ecological Land
Arable
Food
Land
Security
Land use
Goals Construction Land
Ecological Security
Urban Development
Fig. 1. Trade-offs of land use and development goal in regional space.
maintaining regional sustainable development. A new comprehensive national land use plan in China (2006–2020) has clearly outlined the requirements for eco-space, which will focus on the overall arrangements for living, life and ecological space, protect the productive land, give priority to the protection of natural eco-spaces, and promote the development of regional ecological civilization. Ecological civilization is a new concept proposed by Hu Jintao and focuses on a list of elements including the right relationship between man and nature. The ecological evaluation based on GIS was firstly proposed by McHarg in 1960s (McHarg, 1969, 1981). In his book “Design with Nature”, McHarg developed the “pastry mode” of land suitability assessment (McHarg, 1969, 1981). Steinitz developed a landscape evaluation model on behalf of conservation planning ideas, namely, how to determine the biodiversity, appearance, cost, nutrition flow, public health, and other conditions (Steinitz, 1990, 1993). Steiner, McHarg’s student, proposed a model of Environmentally Sensitive Area (ESA) in 2000 (Steiner, 2000). In addition, Malczewski developed a multi-criteria method for the land suitability evaluation based on GIS (Malczewski, 2004; Malczewski et al., 2003). Currently, the importance evaluation of ecological land has primarily focus on a single characteristic such as water security, biodiversity conservation, and soil erosion protection. For example, some studies developed a evaluation method to identify new priority areas that best meet desired the targets in combination with any existing protected areas (PAs) (Moilanen and Arponen, 2011). This method, however, is likely to produce portfolios with a large number of small and isolated protected areas (PAs), and such portfolios are less ecologically and economically feasible (Nhancale and Smith, 2011; Smith et al., 2010; Wiersma and Nudds, 2009). Some studies assessed the degree to which macroecological modelling can overcome shortfalls in our knowledge of biodiversity in tropical forests and help identify priority areas for their conservation and management (Mokany et al., 2014). Through identifying the key areas of water security, some scholars analyzed the ecological, social and economic impacts of their protection and restoration (Brouwer and van Ek, 2004). Some studies identified the key areas of soil erosion protection using GIS and Universal Soil Loss Equation (USLE) (Toumi et al., 2013). In addition, some studies on eco-space are more concerned about how to configure the eco-space to maintain the security of regional ecological environment, and mostly for these studies at small watershed scale. Seppelt took the Hunting Creek small watershed in the southern United States as the experimental area and have designed a spatial configuration scheme of land use and maximum standard amount of chemical fertilizer distribution
to control pollution caused by fertilizers using GIS and spatial differentiation model (Seppelt and Voinov, 2002). For the importance evaluation of regional ecological space, Chinese scholars have mainly focused on ecological sensitivity and ecological suitability (He et al., 2008; Yu et al., 2008). Yu constructed a comprehensive evaluation model for ecological sensitivity based on GIS, which includes ecological protection sensitivity, ecological buffer sensitivity, landscape visual sensitivity, and ecological security sensitivity (Yu et al., 2008). The methods of ecological assessment based on GIS mainly included overlapping factors method, logical combination method (Yan et al., 2009), ecological fitness model (Ouyang et al., 1996), and minimum cumulative resistance model (Liu et al., 2010). The current studies on ecological evaluation mainly focused on the aspects of natural ecology, and the results did not reflect the spatial characteristics of regional ecosystem and maintaining ecological security. The ecological importance evaluation of regional space is to emphasize on the harmonious development between production space, living space, and ecological space, to focus on the symbiosis between man and other organisms, and to maintain the natural foundation of urban development using applied principles in ecology. Based on the analysis of ecological characteristics, ecological importance evaluation is to explore the spatial distribution of regional ecological importance and to provide some measures for preventing ecological security issues from the regional development and construction. The main purposes of this study are (1) to construct an integrated index at spatial scale to assess the importance of regional space maintaining water security, biodiversity conservation, disaster avoidance and protection, natural recreation, (2) to establish an GIS-based approach to identify the key space maintaining ecological security, (3) to propose some zoning regulations and measures for environmental management. 2. Materials and methods 2.1. Study area The study area (115 010 –115 510 E, 26 030 –26 410 N) is Xingguo county in Jiangxi province of China (Fig. 2), which is located in the mid-southern areas and lies to the North of Ganzhou City, at the headwaters of Pinggu River. It is surrounded by the mountains in the east, north, and west. There is a valley basin centered in the county in the south-central, mostly lowmountains and hills. In 2005, the GDP of Xingguo totaled 3.32 billion Yuan. The proportion of three industrial structures is 39.3:31.3: 29.4, and the rural per capita net income is 2376 Yuan in 2005. The study area covers an area of 15.5 km2, and the resident population was 121,000.
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Fig. 2. Study area.
The county belongs to the subtropical southeast monsoon climate, with an annual average temperature of 18.9 C, an extreme maximum temperature of 39.9 C, and an extreme minimum temperature of under 6.3 C. The annual average frost-free period amounts to 248 days. The average annual rainfall is 1516 mm, which is concentrated in April and June, with rainfall from April to June accounts for 48.5% of annual precipitation. 2.2. Data The data of land use, ecosystem type, DEM and NDVI in this study were derived from the National Ecological Environment Decade Change Assessment Database System. The zoning map of Drinking Water Conservation Areas, the map of nature reserves, forest parks, geological parks and scenic areas, and the basic geographic information data of Xingguo county derived from Data Center for Resources and Environmental Sciences of the Chinese Academy of Sciences. Climatic data were derived from the China Meteorological Data Sharing Service System. The soil data in the study were derived from the Second National Soil Survey of China, and the related physicochemical properties and types of soil from the database were collected and analyzed by the Institute of Soil Science at the Chinese Academy of Sciences. Before processing operations, all graphical data were first preprocessing by projection transformation, using the ALBERS equal-area conic projection (Krasovsky_1940_Albers). Through resampling, the spatial resolution is converted to the raster of 50m 50 m. The two operations are realized, respectively, by projecting and resampling, to make sure the projection and precision of the graphics output uniform.
2.3. Methods 2.3.1. General idea of ecological importance evaluation According to the related studies (Allan and Peterson, 2002; Yu et al., 2009; Zagas et al., 2011), the spaces maintaining ecological security mainly consist of the areas for the maintenance of water security, biodiversity protection, disaster avoidance, and recreational area protection. In addition to this, we should consider the influence of human disturbance. Therefore, the general idea of ecological importance evaluation is shown in Fig. 3. 2.3.2. Principals of index selection As a measure of the index system for ecological importance evaluation, not only to be followed by the universal principles including objectivity, integrity and effectiveness, it should also be considered from the following three aspects. (1) Service for the optimization of ecological landscape pattern
The main purpose of ecological importance evaluation of regional space is to provide a basis for the optimization of ecological landscape pattern. Therefore, the evaluation indexes should be able to have spatial characteristics. The evaluation results should be combined with GIS into every land use patches and try to achieve the positioning and quantitative evaluation for ecological landscape, which can provide a theoretical basis for subsequent environmental planning and design. (2) Reflecting the problems of regional eco-security
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Fig. 3. General idea of ecological importance evaluation.
Spatial pattern of regional land use is the outcome caused by human and natural factors. Major eco-environmental problems in the study area include the protection of water and soil resources, biodiversity conservation, and disaster protection and so on. Therefore, considering the accessibility of data, the index system of ecological importance evaluation should be constructed from the eco-problems and by using evaluation methods of ecological sensitivity, with RS and GIS techniques. (3) Operability
The selected indexes should be operational for data collection. The data for selected indexes have some statistical basis, comparability, and testability. The data for selected indexes can be accurately collected, and to be able to quantify the extent possible. 2.3.3. Frame of index system for ecological importance evaluation According to the meaning of ecological importance evaluation and the above principals of indexes selection, a three-level index system has been established to evaluate the ecological importance of regional space (see Fig. 4). The first level of index system is the object layer, namely, the integrative index of ecological importance. The second level is the item layer, namely, the factors influencing the importance of eco-space. The third level is the index layer, which is the individual indexes measuring the influencing factors. 2.3.4. Grading criteria of indexes of ecological importance evaluation Different types of indexes have varied impacts and contributions on ecological importance. After the discussions, amendments and comprehensive evaluation from the dozen experts in relevant disciplines, the grade level of each single factor was determined. Each grade level (extremely important, moderately important, generally important, or not important) is assigned to 7, 5, 3, and 1, respectively. The grading criteria and assigned scores of each index for ecological importance evaluation are listed in Table 1.
2.3.5. Computation of indexes 2.3.5.1. Importance of water security. Water system is one of the important spaces maintaining regional ecosystem health. Identifying the key spaces maintaining water security is to start from the entire watershed, leaving the spaces of wetlands, and river buffers, which can meet the natural vent of flood. At the same time, it also includes the spaces of water sources protection and water storage. Therefore, four indexes have been selected to evaluate the importance of this type of space: the distance to a river or lake, the type of flood storage areas, the type of water source protection areas, and the importance of water storage. With the spatial distributions of rivers and lakes, the index of the buffering distance to a river or lake can be obtained using the module of straight-line distance function in software ArcGIS9.3. The index of the type of flood conditioning storage areas can be obtained from the digitized zoning maps of land use, wetlands, and detention basins. The index of the type of water source protection areas can be obtained from the digitized zoning map of water source protection areas. The index of the importance of water storage can be obtained from the quantity of the water storage of different ecosystems. The formula of the quantity of water storage from different ecosystems is as follows: Q ¼ A J R0 Rg
J ¼ J0 K
(1)
where Q is the increasing quantity of water storage from different ecosystems such as forest or grass ecosystem by the comparison with bare land, A is the area of ecosystem, J is the annual rainfall runoff (P > 20 mm) of average years in the study area, J0 is the annual total rainfall of average years in the study area, K is the proportion of rainfall runoff on total rainfall, R0 is the effectiveness coefficient of bare land reducing runoff. Rg is the effectiveness coefficient of other ecosystems reducing runoff. In this study, the values of K and R refer to the relevant studies (Zhao et al., 2004).Using Formula (1) and
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Distance index to a river or lake Type index of flood storage areas
Water security
Type index of water source protection area Importance index for water storage Habitat sensitivity index Biodiversity
Vegetation coverage
conservation Habitat quality index Integrative Sensitivity index of geological hazards
index of
Disaster protection
Importance index of soil conservation
ecological Importance index of land desertification protection
importance
Natural recreation
Suitability index of natural recreation
Strength index of main roads Human disturbance
Strength index of building land of urban Population congregation index
Fig. 4. Index system for evaluating ecological importance of regional space.
after standardization, we calculated the importance index of water storage for each spatial unit using the module of spatial analysis in software ArcGIS9.3. And then using the standard deviation (1 SD) classification, the importance index of water storage is to divide into four rankings (extremely important, moderately important, generally important, and not important). We used a disjunction function to calculate the ecological importance index of the space maintaining water security (EIIw) for each grid, where the four indexes represent four aspects of maintaining regional water security. The equation is as follows: EIIw ¼ Maxðs1 ; s2 ; s3 ; s4 Þ
(2)
where EIIw represents the ecological importance index of the space maintaining water security, s1 is the index of the distance to a river
or lake, s2 is the index of the type of flood conditioning storage areas, s3 is the index of the type of water source protection areas, and s4 is the index of the importance for water storage. Using Eq. (2), we calculated the ecological importance index of the space maintaining water security for each grid using software ArcGIS9.3. Finally, using the raking standards in Table 1, we obtained the spatial grade map of water security importance. 2.3.5.2. Importance of biodiversity conservation. Biodiversity conservation indexes mainly refer to the influencing factors maintaining regional biodiversity conservation. In this study, three indexes habitat scarcity, vegetation coverage, and habitat quality have been selected to evaluate the ecological importance of the space maintaining biodiversity.
Table 1 Grading criteria and assigned scores for the indexes of the ecological importance evaluation. Index
Extremely important
Moderately important
Generally important
Not important
Distance index to a river or lake (s1) Type index of flood storage areas (s2)
<50 m Wetland areas
50–100 m Core areas of detention basins
>150 m Other areas
Type index of water source protection area (s3) Importance index for water storage (s4) Habitat sensitivity index (s5) Vegetation coverage (s6) Habitat quality index (s7) Sensitivity index of geological hazards (s8) Importance index of soil conservation (s9)
First-grade protection zones of water resources 0.6–1 0.6–1 >0.6 0.6–1 First-grade protection zones of water resources Extremely sensitive
Second-grade protection zones of water resources 0.4–0.6 0.4–0.6 0.4–0.6 0.4–0.6 Second-grade protection zones of water resources Highly sensitive
100–150 m Non-core areas of detention basins Quasi-watershed protection zone 0.2–0.4 0.2–0.4 0.2–0.4 0.2–0.4 Quasi-watershed protection zone Moderately sensitive
Importance index of land desertification protection (s10) Suitability index of natural recreation (s11) Strength index of main roads (s12) Strength index of building land of urban (s13) Population congregation index (s14) Assigned score
Extremely sensitive
Highly sensitive
Moderately sensitive
Extremely suitable
Moderately suitable
Generally suitable
Mildly sensitive/not sensitive Mildly sensitive/not sensitive Not suitable
>500 m >1000 m
200–500 m 500–1000 m
100–200 m 200–500 m
<100 m <200 m
<300 7
300–400 5
400–500 3
>500 1
None 0–0.2 0–0.2 <0.2 0–0.2 None
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According to the equivalent quantum of biodiversity service for different land-use types and the protection grades of different regions, we developed a habitat scarcity index (HSI). The equation for the habitat scarcity index (HSI) is as follows: HSI ¼ nl m
(3)
where, HSI is the scarcity index of habitats, nl is the equivalent quantum of biodiversity service for land use type l,m is the corrected value of the protection ranking. For the nature reserves, parks, scenic areas, and other land-use types, m are assigned values of to 1.75, 1.5, 1.25, and 1, respectively. The index vegetation type can be obtained from the digitized maps of ecosystem type. The index of vegetation coverage (VC) can be obtained from the map of Normalized Difference Vegetation Index (NDVI). The index of the habitat quality reflects the level of biodiversity. The formula of habitat quality index (HQI) is as follows: $ !% Dzxj z þ k HQIxj ¼ Hj 1 Dzxj
Dxj ¼
XY r
XR r¼1
y¼1
irxy ¼ 1
dxy drmax
!
wr
PR
r¼1
wr
ry irxy bx Sjr
(4)
where HQIxj is the habitat quality of the grid x for the land use type j, Hj represents the habitat suitability of land use type j, Dxj refers to the habitat stress level of the grid x for the land use type j. irxy refers to the stress role of the factor r of grid y on the grid x, dxy refers to a straight line between grid x and grid y. drmax represents the maximum effect distance of the stress factor r. wr is the weight of stress factor, which represents the relative damage of a stress factor on all habitats. bx represents the level of accessibility grid x. Sjr represents the sensitivity of the stress factor r on the land use type j. k is the constant of half-saturation. When the formula z 1 ðDzxj =Dzxj þ k Þ is equal to 0.5, the k value is equal to D value. The stress factors considered in this study include natural factors (i.e., natural disaster, landslide and mudslides) and human factors (i.e., road, urban settlements, and farmland). The spatial
distribution data of different stress factors come from the topographic map and the land use map in the study area. We used a product method to calculate the ecological importance index of the space maintaining biodiversity (EIIb) for each grid, where the three indexes represent three aspects of maintaining regional biodiversity. The equation is as follows: vffiffiffiffiffiffiffiffiffiffi u n Y u n (5) EIIb ¼ t Si i¼1
where EIIb represents the ecological importance index of the space maintaining biodiversity, Si represents the assigned score of evaluation indicator i, which is obtained using the raking standards in Table 2. In the importance evaluation of biodiversity conservation, evaluation indicators include habitat scarcity index, vegetation coverage and habitat quality index. Using Eq. (5), we calculated the ecological importance index of the space maintaining biodiversity for each grid using software ArcGIS9.3. Finally, we can obtain a spatial grade map of biodiversity conservation importance using the raking standards in Table 1. 2.3.5.3. Importance of disaster protection. Disaster protection evaluation is to mainly identify the ecological space of disaster risk aversion and disaster protection. In this study, three indexes sensitivity of geological hazard zones (s8), importance of soil conservation (s9), and importance of land desertification protection (s10) are selected to evaluate the importance space of disaster protection. The spatial distribution of geo-disaster danger area can be obtained from the digitized map of sensitivity analysis for landslide and debris flow. The index sensitivity of geological hazard zones is obtained from sensitivity evaluation of the geological hazards in the study area including landslides and debris flows. Using the universal soil loss equation (USLE), we evaluated the soil erosion sensitivity in the study area. The universal soil loss equation (USLE) includes five indexes rainfall and runoff (R), soil erodibility (K), slope and slope length and crop/vegetation and management (C). We also evaluated land desertification sensitivity using four indexes humidity, the days with wind speed greater than 6 m/s in winter and spring, soil texture and vegetation coverage in winter and spring. The evaluation method for soil erosion sensitivity and land desertification sensitivity refers to the related studies (Xie, 2008; Yan et al., 2009).
Table 2 Results of the evaluation of ecological importance in Xingguo county. Evaluation factors
Importance ranking
Areas (hm2 align="center")
Percentage of total area (%)
Cumulative percentage of total area (%)
Water security
Extremely important Moderately important Generally important Not important
67987.98 127930.95 55904.22 69178.86
21.18 39.85 17.42 21.55
21.18 61.03 78.45 100.00
Biodiversity conservation
Extremely important Moderately important Generally important Not important
26190.72 154256.49 74277.36 66277.44
8.16 48.05 23.14 20.65
8.16 56.21 79.35 100.00
Extremely important Moderately important Generally important Not important
31997.52 130165.92 81725.85 77112.72
9.97 40.55 25.46 24.02
9.97 50.52 75.98 100.00
Extremely important Moderately important Generally important Not important
3687.84 8942.49 116311.32 192048.48
1.15 2.79 36.23 59.83
1.15 3.93 40.17 100.00
align="left" Disaster protection align="left"
align="left" Natural recreation
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We used a disjunction operation to calculate the ecological importance index of the space protecting disasters for each grid. The equation is as follows: EIId ¼ Maxðs8 ; s9 ; s10 Þ
(6)
where EIId represents the ecological importance index of the space protecting disasters, s8 is the sensitivity index of geological hazard zones, s9 is the importance index of soil conservation, and s10 is the importance for land desertification protection. 2.3.5.4. Importance of natural recreation security. Ecological land not only can preserve soil and water conservation, provide habitats for the species and protect disaster, but also has the function of natural recreations. In this study, we identified the important space maintaining natural recreation security with a natural recreation suitability index. The ecosystems with high entertainment value are important for residents to enjoy natural recreation activities. Based on land use type and the equivalent quantum of entertainment service established by previous studies (Xie et al., 2003; Yan et al., 2009), we corrected the equivalent quantum of recreation service. The formula of the natural recreation suitability index is given as follow: EIIr ¼ pl q
(7)
where EIIr is the ecological importance index of space providing natural recreation, pl is the equivalent quantum of entertainment service for land use type l, and q is the corrected recreation ranking value. Parks, scenic areas, nature reserves and other lands are assigned the values of 1.75, 1.5, 1.25, and 1, respectively. Using the Eq. (4), we calculated the natural recreation suitability index for each spatial unit using the module of spatial analysis in software ArcGIS9.3. And then using the standard deviation (1 SD) classification, the natural recreation suitability is to divide into four rankings (extremely suitable, moderately suitable, generally suitable, and not suitable). 2.3.5.5. Influence of human disturbance. Human disturbance evaluation mainly reflects the degree of interference of human activities on ecological space, and its influence is inversely proportional with ecological importance. In other words, the higher the human interference coefficient is, the lower the ecological importance of the space will be. In this study, three indexes strength of main roads, strength of construction land of urban and town, and population congregation are selected to evaluate the degree of interference of human activities. With the spatial distributions of the road and construction land of urban and town, the two indexes of the strength of main roads and the strength of building land of urban and town can be obtained using the module of straight-line distance function in software ArcGIS9.3. These two indexes reflect the impacts of transportation and construction land on eco-environment and the attenuation characteristics with distance. The index of the population aggregation reflects the degree of human disturbance on ecological land. The larger population aggregation index and the greater the degree of interference with the ecological land is, the lower the ecological importance of the space will be. The formula of population aggregation index (PAI) is as follows: PAIj ¼
pj nl
(8)
where PAIj is the value of population aggregation index of the residential area j, pj is the total population of the demographic areas j, n is the total number settlements in the j-th statistical area. l Is a weighting value, which is an inverse distance weighted value by the distance from the urban or town centers and roads. Based on
7
the above formula, the spatial distribution of population aggregation index can be interpolated by Kriging model. The integrated index of human disturbance was obtained by the same method of ecological importance index of the space maintaining biodiversity (EIIb). Using Formula (8), we calculated the integrated index of human disturbance (EIIh) for each grid using software ArcGIS9.3. Finally, we can obtain a spatial grade map of human disturbance influence using the raking standards in Table 1. 2.3.6. Integrated evaluation of ecological importance Due to the different eco-spaces maintaining ecological security are independent, in order to highlight the importance status of ecosystem maintaining ecological security, a comprehensive evaluation of eco-space importance is conducted by using the maximum value method. Based on the evaluation of eco-space importance, we considerd the influence of human disturbance. Its formula of the ecological importance of integrated evaluation for space (EIIS) is as follows: EIIS ¼ MaxðEIIw ; EIIb ; EIId ; EIIr ÞIEIIh
(9)
where EIIS is the ecological importance of integrated evaluation for regional space, EIIw is the ecological importance index of the space maintaining water security, EIIb is the ecological importance index of the space maintaining biodiversity conservation, EIId is the ecological importance index of the space maintaining disaster protection security, EIIr is the ecological importance index of the space providing natural recreation, EIIh is the integrated index of human disturbance. 3. Results and discussion The results of importance evaluation for the space maintaining single ecological security in Xingguo county are listed Table 2 and shown in Fig. 5. For the importance of water security, the area of extremely important is 67,987.98 hm2, accounting for 21% of the total area (see Table 2). These areas are extremely valuable for the maintenance of local water security, including water resource conservation and flood regulation and storage. Fig. 5(a) shows that the key spaces maintaining water security mainly consist of woodlands and regional river systems, which located in the northern and southern mountains in the study area. There are good quality and significant functions of water conservation for the woodlands in these areas, and the lake-river system in these areas plays a vital role in flood control. For biodiversity conservation, the results of importance evaluation are shown in Fig. 5(b) and Table 2. From Table 2, the area of extremely important for maintaining biodiversity conservation accounts for 8% of the total area. These areas mainly consist of the core area of Mountain Nature Reserve (see Fig. 5(b)). The sunny and half-sunny slopes of these areas contain deciduous broad-leaved forest, mainly consisting of fir and pine, which is the core habitat of most biological species. Although there is a small key area for biodiversity conservation, it mostly covers the habitats of regionally rare species and key species. Therefore, it is important for maintaining biodiversity security to identify the ecological processes of biodiversity conservation and to build an urban and rural local continuous habitation and bio-corridor system. The area of moderately important for maintaining biodiversity is 154,256.49 hm2, which mainly consist of woodlands, which acts as the buffer for native biological species and locate in the mountains. The area of extremely important, moderately important, and important for maintaining biodiversity makes up close to 60% of the total area.
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Fig. 5. Results of evaluation of ecological importance for single security in Xingguo county.
As can be seen from Fig. 5(c) and Table 3, for disaster avoidance and protection, the area of extremely important is 31,997.52 hm2, accounting for 10% of the total area. These areas are the extremely dangerous areas due to geological hazard such as landslide and mudflow. Considering the security of residents, construction development should be avoided in these areas. Meanwhile, the region is characterized by sparse vegetation, thick loess cover, and severe soil erosion. Large areas prone to geomorphic hazards, such as landslides, mudslides, and soil erosion, should be regarded as the emphasis region of evasion and protection. The area of moderately important is 130,165.92 hm2, accounting for 40% of the total area. These areas of extremely important, moderately important, and important should be vigorously for planting trees and grass, reforestation and to avoid large-scale development and construction activities. From Fig. 5(d) and Table 2, for natural recreation importance, the area of extreme importance and moderate importance accounts for 4% of the total area. These areas primarily consist of the core areas of forest parks, scenic spots and river systems. These areas have high values for natural recreation due to land use types are wetlands and woodlands. As the growing demands for outdoor recreation, wetlands and forests have become the open recreational spaces for the residents. For the sustainable development in these areas, some measures should be put forward, including controlling the capacity for tourists, avoiding the over
exploitation from tourism, and protecting the natural landscape with high recreational value. According to above results of importance evaluation for the spaces maintaining water security, biodiversity protection, disaster avoidance, and recreational area protection, we then considered the impacts of human disturbance and obtained the integrated result of evaluation eco-space importance in Xingguo county (see Table 3 and Fig. 6). From Fig. 6, we can see that the extremely important ecological land is mountains and mainly located in the north and east of study area. These areas mainly consist of the core areas of river systems, wetlands, nature reserves and forest land, and the protection zones of soil erosion, which are the ecological barrier for maintaining homeland security. There are high vegetation cover, rich biodiversity, and weak resistance to natural disasters in the areas of extremely important ecological land, where man-made disturbances can not afford. The area of the extremely important ecological land is 96,025.68 hm2, accounting for 30% of the total area, which are the ecological “red line” for the maintenance of regional eco-security and should be strictly protected and included in prohibited exploitation zone, and prohibited any exploitation and construction activities. The concept of the ecological “red line” is established to provide more space provided for nature to restore itself. Ecological “red line” requires all regions to optimize, prioritize, restrict, or prohibit their industrial development
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Table 3 Integrated evaluation result of the eco-space importance in Xingguo county. Importance ranking
Areas (hm2 align="left")
Percentage of total area (%)
Cumulative percentage of total area (%)
Extremely important Moderately important Generally important Not important
96025.68 112527.45 69615.45 42833.43
29.91 35.06 21.69 13.34
29.91 64.97 86.66 100.00
according to their defined nature. The directions of ecological protection and construction in these areas are focused on the ecological conservation, the improvement of water conservation function, the construction of ecological projects in forestry, the purification for water and the protection of biodiversity. The areas of moderately important ecological land are 112,527.45 hm2, accounting for 35% of the total area. These areas are located in the buffer zone of the extremely important ecological land, including the ecological buffer zones of the river systems and the core area of biodiversity conservation (see Fig. 6). There are fragile eco-environment, weak self-regulation, and poor stability in these areas, where serious ecological degradation may occur under the man-made or natural disturbances. Therefore, they are the key areas of ecological risk prevention. These areas are designated as the restricted development zones, where limiting the activities of development and construction. The regulations in the moderately important eco-space include strengthening the conservation for the existing vegetations, prohibiting the activities of damaging eco-environment such as deforestation and other
unauthorized reclamations, and effective recovery or reconstruction for the destroyed vegetations. The area of moderately important ecological land is 69,615.45 hm2, accounting for 21% of the total area. These areas are mainly located in the southern regions of study area, including the transition zone of moderately sensitive area, the main catchment areas of surface runoff and the secondary areas of ecological buffer zone along rivers or lakes (see Fig. 6). From the start of protecting natural ecosystems, ecological regulations in these regions include adjusting the structure and layout of industrial, formatting the green industry with small environmental damage and high added value and building the ecological corridors and the eco-industrial development zone maintaining ecological security. The area of not important eco-space is 42,833.43 hm2, only accounting for 13% of the total area, which are mainly built-up areas and arable land and mainly responsible for human habitation and agricultural production. Therefore, the regulations in these areas include the reasonable controls of population size, the
Fig. 6. Integrated evaluation of ecological importance of space in Xingguo county.
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adjustments of industrial structure, and the development of ecoindustries. As one of the important theories in ecology, niche is widely used in the natural and socio-economic systems in recent years. The meaning of niche theory is constantly expanding, and gradually developed from species niche to biodiversity conservation niche and urban niche and so on (Costa et al., 2010). The spatial evaluation of ecological important must also consider the land demands from socio-economic development and urbanization in the future. Therefore, considering the scenarios of economic development and the effects from land-use in the surrounding area, some scenarios simulations for the ecological importance of regional space is the research direction using ecological bit cellular automata (CA) model in the future. 4. Conclusions The method of evaluating eco-space importance in this study is better than the existing ones. Firstly, the evaluation method developed in this study is based on the demands of maintaining regional eco-security. Secondly, compared to current studies, it has considered many factors including water security, biodiversity conservation, disaster avoidance and protection, natural recreation and human disturb. Thirdly, a GIS-based approach can propose the results of the explicit and feasible multi-scenarios, which facilitates the effective management of ecological space. The results show the spatial characteristics of eco-space for maintaining the water security, biodiversity, disaster protection and recreation, which indicate that the spatial method for ecological importance evaluation in this study is feasible. The area of extremely important eco-space accounts for 30% of the total area, which is the endangered and protected zones of geological hazards and the core areas of regional river systems, wetlands, nature reserves, forest parks, and scenic spots. These spaces are the bottom line for maintaining ecological security. For the spatial characteristics of ecological importance in different regions, some zoning regulations and measures should be proposed for environmental management. Acknowledgements This study was supported by the National Natural Science Foundation of China (No. 41361111 and No. 41461019), the Fok Ying Tung Foundation (No. 141084), the Natural Science Foundation of Jiangxi Province (No. 20142BAB203028), the Technology Foundation of Jiangxi Education Department of China (No. KJLD14033 and No. GJJ14346), and the Social Science Foundation of Jiangxi Province (No. 13GL05). References Allan, I., Peterson, J., 2002. Spatial modeling in decision support for land- use planning: a demonstration from the Lal Lal catchment, Victoria, Australia. Aust. Geog. Stud. 40, 84–92. Brouwer, R., van Ek, R., 2004. Integrated ecological: economic and social impact assessment of alternative flood control policies in the Netherlands. Ecol. Econ. 50, 1–21. Costa, G.C., Nogueira, C., Machado, R.B., 2010. Sampling bias and the use of ecological niche modeling in conservation planning: a field evaluation in a biodiversity hotspot. Biodivers. Conserv. 17, 883–899. He, X., Xue, P., Zhang, N., 2008. Evaluation of ecological suitability in Changping district of Beijing city. Acta Scientiarum Naturalium UN. 41, 50–56.
Li, X.B., 1996. Core of global environmental change research: frontier in land use and coverage change. Acta Geog. Sin. 51, 553–558. Liu, X., Su, J., Zhang, L., 2010. Research on applying minim a l cumulative resistance model in urban land ecological suitability assessment: as an example of Xiamen city. Acta Ecol. Sin. 30, 421–428. Maccagnani, B., Ferrari, R., Pozzati, M., 2013. Ecological infrastructure management for enhanced pollination and targeted precision biocontrol: the bicopoll project. Bull. Insectol. 66, 26. Malczewski, J., 2004. GIS-based land-use suitability analysis: a critical overview. Prog. Plann. 62, 3–65. Malczewski, J., Chapman, T., Flegel, C., Walters, D., Shrubsole, D., Healy, M.A., 2003. GIS – multicriteria evaluation with ordered weighted averaging (OWA): case study of developing watershed management strategies. Environ. Plann. A 35, 1769–1784. McHarg, I., 1969. Design with Nature. Natural History Press, New York. McHarg, I., 1981. Human planning at Pennsylvania. Landscape Plann. 8, 109–120. Moilanen, A., Arponen, A., 2011. Administrative regions in conservation: balancing local priorities with regional to global preferences in spatial planning. Biol. Conserv. 144, 1719–1725. Mokany, K., Westcott, D.A., Prasad, S., Ford, A.J., Metcalfe, D.J., 2014. Identifying priority areas for conservation and management in diverse tropical forests. PLoS One 9 doi:http://dx.doi.org/10.1371/journal.pone.0089084. Nhancale, B.A., Smith, R.J., 2011. The influence of planning unit characteristics on the efficiency and spatial pattern of systematic conservation planning assessments. Biodivers. Conserv. 20, 1821–1835. Ouyang, Z., Wang, R., Fu, G., 1996. Ecological niche suitability model and its application in land suitability assessment. Acta Ecol. Sin. 16, 113–120. Rouget, M., Cowling, R.M., Pressey, R.L., Richardson, D.M., 2003. Identifying spatial components of ecological and evolutionary processes for regional conservation planning in the Cape Floristic Region South Africa. Divers. Distrib. 9, 191–210. Scholz, M., Hedmark, A., Hartley, W., 2012. Recent advances in sustainable multifunctional land and urban management in Europe: a review. J. Environ. Plann. Manag. 55, 833–854. Seppelt, R., Voinov, A., 2002. Optimization methodology for land use patterns using spatially explicit landscape models. Ecol. Modell. 125–142. Smith, R.J., Di Minin, E., Linke, S., Segan, D.B., Possingham, H.P., 2010. An approach for ensuring minimum protected area size in systematic conservation planning. Biol. Conserv. 143, 2525–2531. Steiner, F., 2000. A watershed at a watershed: the potential for environmentally sensitive area protection in the upper San Pedro Srainage Basin (Mexico and USA). Landscape Urban Plann. 129–148. Steinitz, C., 1990. A framework for theory applicable to the education of landscape architects and other environmental design professionals. Landscape J. 136–143. Steinitz, C., 1993. A framework for theory and practice in landscape planning. GIS Eur. 42–45. Toumi, S., Meddi, M., Mahe, G., Brou, Y.T., 2013. Remote sensing and GIS applied to the mapping of soil loss by erosion in the Wadi Mina catchment. Hydrol. Sci. J. – J. Sci. Hydrol. 58, 1542–1558. Vitousek, P.M., Mooney, H.A., Lubchenco, J., Melillo, J.M., 1997. Human domination of Earth’s ecosystems. Science 277, 494–499. Wiersma, Y.F., Nudds, T.D., 2009. Efficiency and effectiveness in representative reserve design in Canada: the contribution of existing protected areas. Biol. Conserv. 142, 1639–1646. Xie, G.D., Lu, C.X., Leng, Y.F., Zheng, D., Li, S.C., 2003. Ecological assets valuation of the Tibetan Plateau. J. Nat. Resour. 18, 189–196. Xie, H., 2008. GIS-based land-use eco-security evaluation in typical agro-pastoral zone. Chin. J. Ecol. 27, 135–139. Xie, H., Liu, Z., Wang, P., Liu, G., Lu, F., 2014. Exploring the mechanisms of ecological land change based on the spatial autoregressive model: a case study of the Poyang lake eco-economic zone, China. Int. J. Environ. Res. Public Health 11, 583–599. Xie, H.L., Kung, C.C., Zhang, Y.T., Li, X.B., 2012. Simulation of regionally ecological land based on a cellular automation model: a case study of Beijing, China. Int. J. Environ. Res. Public Health 9, 2986–3001. Yan, L., Xu, X.G., Xie, Z.L., 2009. Integrated assessment on ecological sensitivity for Beijing. Acta Ecol. Sin. 29, 3117–3125. Yu, K.J., Qiao, Q., Li, D.H., 2009. Ecological land use in three towns of eastern Beijing: a case study based on landscape security pattern analysis. Chin. J. Appl. Ecol. 20, 1932–1939. Yu, S., Wang, Y., Li, J., 2008. Appraisal of eco-sensitivity on small sized industrial city in Northern China: set the Shahe city as an example. J. Fudan Univ.: Nat. Sci. 47, 501–508. Zagas, T.D., Raptis, D.I., Zagas, D.T., 2011. Identifying and mapping the protective forests of southeast Mt. Olympus as a tool for sustainable ecological and silvicultural planning, in a multi-purpose forest management framework. Ecol. Eng. 37, 286–293. Zhao, T., Ouyang, Z., Zhang, H., 2004. Forest ecosystem services and their valuation in China. J. Nat. Resour. 19, 480–491.
Please cite this article in press as: Xie, H., et al., Spatial evaluation of the ecological importance based on GIS for environmental management: A case study in Xingguo county of China. Ecol. Indicat. (2014), http://dx.doi.org/10.1016/j.ecolind.2014.08.042