- Email: [email protected]
Evaluation of Land-Use Efficiency Based on Regional Scale
Jun. 2007
Journal of China University of Mining & Technology
Vol.17
No.2
J China Univ Mining & Technol 2007, 17(2): 0215–0219
Evaluation of Land-Use Efficiency Based on Regional Scale —A Case Study in Zhanjiang, Guangdong Province CHEN Shi-yin1,2, LIU Yao-lin1, CHEN Cui-fang1 1
College of Resources and Environmental Science, Wuhan University, Wuhan, Hubei 430079, China 2 College of Agriculture, Guangdong Ocean University, Zhanjiang, Guangdong 524088, China
Abstract: Evaluating land use efficiency is critical to the revision of general land use planning. An assessment indicator system for regional land use efficiency was established in this paper from the aspects of society, economy, ecology and environment. The weight of each indicator was defined by an analytical hierarchy process (AHP) and the entropy method (EM). Then, a case study in Zhanjiang was carried out to analyze the regional land use efficiency from 1996 to 2004 and its development by using the method of multifactor composite evaluation and an analytical model of the degree of coordination. The results indicate that land use efficiency with respect to society and the economy improved, whereas the ecological and environmental efficiencies were found to decrease. The degree of coordination in Zhanjiang is still at the status of basic coordination. Finally, measures for enhancing the ecological and environmental establishment are suggested in order to improve the regulations of land use structure and patterns, establish ecological forests for the public good and green corridors and prevent the soil erosion. Key words: regional scale; land-use efficiency; degree of coordination; evaluation CLC Number: F 301.24
1
Introduction
The purpose of land use is to achieve economic, social, ecological and environmental efficiencies, which ought to be the ultimate results of the utilization of land resources. Evaluation of land use efficiency is essential to the revision of general land use planning and land use regulations. It is expected that it will exert considerable effect on the promotion of sustainable land use as well as a sustainable development of society and the economy. Increased land use efficiency on the basic premise of our country during the progress of socio-economic development, has aroused unprecedented attention. China is a country with a vast population and a scarcity of land on a per capita basis. The contradiction between land and population is evident in the annual decrease in the area of cultivated land, so studies about how to evaluate land use efficiency is very popular in China[1–9]. While recent studies are mainly focused on the evaluation of urban and single land use efficiencies,
reports on multiple land use efficiency are few. In order to optimize and regulate the regional land use structure and revise the general regional land use planning, an assessment indicator system for regional land use efficiency is established in our paper, from the point of view of society, the economy, ecology and the environment. By applying the methods of an analytical hierarchy process (AHP) and an entropy method (EM), the weight of each indicator was defined. A case study in Zhanjiang was carried out to analyze the regional multiple land use efficiency and its evolution from 1996 to 2004 by means of a multifactor composite evaluation and an analytical model for the degree of coordination.
2 2.1
Evaluation Indicator and Process Principle
An indicator is a measure of evaluation of land use efficiency. The following principles should be ob-
Received 25 August 2006; accepted 28 September 2006 Projects 20055090032 supported by the Committees of Scientific and Technological Planning Project of Guangdong Province and 0512127 by the Natural Science Foundation of Guangdong Ocean University Corresponding author. Tel: +86-13828247596; E-mail address: [email protected]
216
Journal of China University of Mining & Technology
served when choosing indicators. 1) Scientific: indicators and their choice must be scientifically based. 2) Comprehensive: land use efficiency should be comprehensively and objectively represented. 3) Comparable: the meaning of indicators should be as uniform as possible. 4) Obtainable: indicator data should be accessible and credible. 5) Accurate: multiple land use efficiency should be clearly and exactly reflected. 6) Dynamic: indicators should be able to reflect future prospects and accommodate changes in the land use ecosystem. 2.2
Indicators
We established 24 evaluation indicators for multiple efficiency in regional land use from the aspects of society, economy, ecology and environment according to the principles listed above and the characteristics of regional social, economic development and land use ecosystems. 2.2.1 Economic efficiency in land use (X1) Economic efficiency in land use refers to labor consumption (including physical and intellectual labor) and the labor products or values according to social requirements. The main indicators are: land use ratio (X11), GDP per unit of land (X12), average GDP per person (X13), average constructive land per person Table 1
Garden land 1265.5
Climate control
787.5
1170.3
Headwater conservation
530.9
41.5
Erosion control
(yuan/hm2)
Water area
Residential area
Transportation land
Un-utilized land
707.9
－
－
－
－
796.4
407.0
－
－
－
707.9
18033.2
–6678
－
26.5
Woodland
Meadow
1902.5 1592.8 1769.7
－
796.8
796.8
102.9
－
3480
3480
－
Soil shape
1291.9
1291.9
2588.2
1725.5
8.8
－
－
17.7
Rubbish disposal
1451.2
722.1
1159.2
1159.2
16086.6
–2174.1
－
8.8
Biodiversity protection
628.2
16.6
1924.6
964.5
2203.3
－
－
300.8
Food yield
884.9
356.9
177
265.5
88.5
－
－
8.8
Raw materials produce
88.5
1145.4
1172.4
44.2
8.8
－
－
－
Recreation and culture
8.8
547.8
584
35.4
3840.2
－
－
8.8
6114.3
7354.8
13667.2
6509.4
40676.4
–5372.1
3480
371.4
Total
No.2
(X14), average farmland per person (X15), value of total industrial production per unit land (X16), value of total agricultural production per unit of land (X17), unit yield of food crop (X18), urbanization level (X19) and investment in fixed assets (X110). 2.2.2 Social efficiency in land use (X2) Social efficiency in land use refers to the degree of satisfaction in land use for social requirements and the effect of land use, including: population density (X21), ratio of self-sufficiency in food production (X22), proportion of land use for transportation (X23), Engel index (X24) and income per population (X25). 2.2.3 Ecological efficiency in land use (X3) Ecological efficiency in land use refers to the degree of effect and improvement of land use processes and the contribution to the maintenance of the ecological balance resulting from land utilization. Four indicators were adopted, which were the proportion of ecological land (X31), value of ecological services (X32), landscape diversity index (X33), degree of water and soil erosion (X34). 1) Value of ecological services Costanza et al. proposed a method for calculating the value of services of ecosystems in 1997 and Xie Gaodi et al have provided “the table of ecological service values of China’s ecosystem” based on the study by Costanza et al [10–11]. According to previous studies, we can obtain ecological service values of different land use types in Zhanjiang (Table 1).
Ecological service values of different land-use types
Cultivated land 442.4
Fume conditioning
Vol.17
Note: data from references [10] and [11].
2) Landscape diversity index We use as model the Gibbs-Mirtin’s diversity index to appraise landscape diversity:
GM = 1 −
n
∑ i =1
n
f i 2 /( ∑ f i ) 2
(1)
i =1
where GM represents the diversity index, fi denotes the area of different land types and n is the number of land types. 2.2.4 Environmental efficiency in land use (X4) Environmental efficiency in land use refers to the effects and changes of environment quality posed by
land utilization. Five indicators were selected: waste water per unit of industrial land (X41), exhaust emission per unit of industrial land (X42), waste residue per unit of industrial land (X43), fertilizer used per unit of cultivated land (X44) and pesticide used per unit of cultivated land (X45). 2.3
Process
2.3.1 Confirmation of weights Confirmation of weights of the multi-indicators is the key step of the evaluation process. Researchers have divided the methods of weight confirmation into
CHEN Shi-yin et al
217
Evaluation of Land-Use Efficiency Based on Regional Scale
two types: subjective and objective methods. The subjective methods obtain the weights of indicators by subjective estimation according to the experts’ experience, such as Delphli and AHP [12]. Weights given by objective methods come from the actual indicator data, which are entirely objective and do not depend on subjective estimates, such as Principal Component Analysis (PCA) and EM. In our study, we applied the combined methods of AHP and EM to confirm the weights of indicators and the weights are presented as average values of these two methods. We have constructed five matrices based on the important degree of each indicator marked 1 to 9 according to the AHP and ranked them generally on an Table 2
individual basis, so we could obtain the weights of 24 evaluation indicators (Table 2), which could, as well, pass the consistency test. Regional land use efficiency evaluation is a sort of comprehensive evaluation with multiple indicators and the degree of difference between the indicators could be shown by information entropy. We could, therefore, adopt the entropy method to calculate the weights of evaluation indicators of regional land use efficiency (Table 2). Detailed calculations can be seen in references [7] and [13] with k=1/log2n＞0 (k is an adjustment coefficient).
Weights of evaluation indices of regional land-use efficiency
Indicators
X1
X2
X3
X4
X21
X22
X23
X24
X25
AHP
0.4373
0.2789
0.1206
0.1632
0.1534
0.1816
0.2566
0.2184
0.19
EM
0.4184
0.2073
0.1654
0.2092
0.1996
0.1999
0.2006
0.2
0.1999
Weights
0.4278
0.2431
0.143
0.1862
0.176 5
0.1908
0.2286
0.2092
0.1950
λmax = 4.0355; CI = 0.0118; RI = 0.90
λmax = 5.0028; CI = 0.0007; RI = 1.12
Indicators
X11
X12
X13
X14
X15
X16
X17
X18
X19
X110
AHP
0.0539
0.1329
0.1050
0.0678
0.0627
0.1360
0.0981
0.0776
0.0865
0.1795
EM
0.0988
0.1011
0.1002
0.0989
0.099
0.1018
0.1001
0.099
0.099
0.1022
Weights
0.0764
0.1170
0.1026
0.0833
0.0808
0.1189
0.0991
0.0883
0.0927
0.1409
Indicators
X31
X32
X33
X34
X41
X42
X43
X44
X45
AHP
0.2764
0.1943
0.1653
0.364
0.2732
0.1912
0.2623
0.1317
0.1416
EM
0.2498
0.2498
0.2498
0.2506
0.1991
0.201
0.2042
0.1982
0.1975
Weights
0.2631
0.2221
0.2076
0.3073
0.2362
0.1961
0.2333
0.1650
0.1696
λmax = 10.0201; CI = 0.00223; RI = 1.49
λmax = 4.0091; CI = 0.003; RI = 0.90
λmax = 5.0100; CI = 0.0025; RI = 1.12
Note: data from Zhanjiang statistics yearbook (2005); where λmax is the biggest characteristic root of matrix vector, CI is the consistency index and RI is the average Stochastic consistency index.
2.3.2 Indicator standardization Since the evaluation indicators of regional land use efficiency will be compared among different indices, they must be standardized. In order to make the result more accessible, an improved efficacy function was adopted [6], which is widely used in related studies
U A( X i )
⎧ X i − bi ⎪ a −b ⎪ i i =⎨ ⎪ ai − X i ⎪⎩ ai − bi
Positive efficacy
(2) Negative efficacy
where U A( X i ) represents the value of the efficacy function, Xi denotes the indicator, bi implies the lower limit of indicators (the minimum of all indicators in our paper) and ai implies the upper limit of indicators (the maximum of all indicators). 2.3.3 Efficiency index of multiple land use We obtained the regional land use multiple efficiency indices using the method of linear weighted sum (LWS) after calculating the efficiency values of the selected indicators and their individual weights. Therefore, the efficiency index of multiple land use
can be defined as follows: F = U1 ⋅ W1 + U 2 ⋅ W2 + " + U n ⋅ Wn = n
∑U
i
⋅ Wi
(3)
i =1
where F represents the efficiency index of multiple land use, Wi is the weight of indicator i and Ui denotes the efficacy value of the indicator. 2.3.4 Degree of coordination In essence, land use efficiency evaluation aims to obtain not only the index value of multiple land use efficiency but also the degree of coordination of each land use efficiency subsystem[9]. According to this systemic point, the degree of coordination of land use efficiency refers to the degree of consistency in each individual subsystem in the total ecosystem during the regional land use process. If the values of the degrees of coordination of each subsystem are close, the process of regional land use will be more harmonious. The degree of coordination of regional land use can be defined as follows:
218
Journal of China University of Mining & Technology
Hi = 1 – Si / Mi (i =1, 2, 3, …, n)
3 Land-Use Efficiency Evaluation in Zhanjiang Zhanjiang is located in the southwest of Guangdong province (109°41′–110°58′E, 20°07′– 21°57′N), and bordered by the sea at the east, south and west. Administrative regions include two counties (Xuwen and Suixi), three county-level cities (Wuchuan, Lianjiang and Leizhou), four districts (Chikan, Xiashan, Potou and Mazhang), the Zhanjiang economic and technological development zone and the Donghaidao
4
Value indicators for evaluation land-use efficiency in Zhanjiang from 1996 to 2004
Index
1996
1997
1998
1999
2000
2001
2002
2003
2004
Economic
0.2274
0.2988
0.3846
0.3990
0.3423
0.3744
0.4948
0.5423
0.7538
Social
0.0680
0.2361
0.2954
0.5545
0.5436
0.5987
0.5496
0.6984
0.8345
Ecological
0.4852
0.5827
0.5618
0.5867
0.5822
0.6481
0.5435
0.4511
0.3858
Environmental
0.8591
0.6465
0.5554
0.4766
0.6850
0.5766
0.4233
0.4070
0.3154
Multiple
0.3431
0.3889
0.4201
0.4781
0.4894
0.5057
0.5019
0.5421
0.6392
Coordinate degree
0.1577
0.5381
0.7076
0.8334
0.7332
0.7808
0.8839
0.7546
0.5461
Development of Land-Use Efficiency
The changes in efficiency of the subsystems and multiple land use system are obvious in Zhanjiang from 1996 to 2004 (Fig. 1).
Fig. 1
No.2
economic development zone. There are 88 villages or towns, 31 neighborhood offices, 1501 village committees and 273 community neighborhood committees in 2004. It covers an area of 13225.4 km2 with a population of 7.159 million, of which the non-agricultural population is 1.915 million. The area is for 26.8 % urbanized. The population density is 574 persons/km2 and per capita land resources 0.18 hm2. In 2004, its GDP, in current prices, was 60.816 billion yuan with 8495 yuan per capita. We calculated the multiple land use efficiency indices and degrees of coordination after standardizing the original values of the evaluation indicators (Table 3): As the results show, the index of social efficiency was the highest in 2004 with a value of 0.8345 and the index of economic efficiency reached 0.7538, which reflects higher social and economic returns, but ecological and environmental efficiency were low, 0.3858 and 0.3154 respectively. The comprehensive land use efficiency index was 0.6392 with the value of 0.5461 for the degree of coordination of the ecosystem, showing that the ecosystem retained the status of basic coordination.
(4)
where Hi represents the degree of coordination, Si denotes the standard deviation of four indices and Mi is the average value of the four indices. The degree of coordination Hi is between 0 and 1 and the ecosystem will be more harmonious if this value is large. Generally, when Hi≥0.7, it indicates that each subsystem of regional land use ecosystem is highly harmonious while the ecosystem is in basic harmony with 0.4≤Hi＜0.7 and when Hi＜0.4 , the ecosystem is not harmonious[14].
Table 3
Vol.17
Development of land-use efficiency in Zhanjiang from 1996 to 2004
There was a remarkable increase in economic efficiency and social efficiency, especially the social efficiency, which jumped from 0.068 to 0.8345 with the average annual growth ratio of 9.58%. However, the ecological and environmental efficiencies declined. A noticeable decrease was observed in environmental efficiency, which fell from 0.8591 to 0.3154 with average annual decline of 6.79%. The multiple efficiency was relatively stable, growing at a rate of 3.7%. From the point of view of the change of degree of coordination, there is no clear indication in the change of the degree of coordination. Between 1996 to 2004, the land use ecosystem, as measured by the degree of coordination,was very similar in 1997 and 2004. Except for 1996 when the degree of coordination was 0.1577, denoting a highly un-coordinated state, the degree of coordination in the other years remained fairly steady, especially in the years 1999 and 2002, when it reached a high level of coordination with the highest degree of coordination in the year 2002.
CHEN Shi-yin et al
Evaluation of Land-Use Efficiency Based on Regional Scale
5 Conclusion The results indicated that the social and economic efficiency of land use in Zhanjiang were high, while ecological and environmental efficiency became low, leading to a low degree of coordination of land use efficiency and a basic coordination status at present. Therefore, in order to ensure the sustainable use of land resources and sustainable socio-economic development, land use must be maintained in the context of social and economic efficiency and ecological and environmental establishment of land use should be strengthened. The following suggestions might be observed in the revision of general land use planning: 1) We must strengthen the adjustment of land use structures and patterns to ensure the implementation of returning farmland to forest and grassland projects and increase the diversity of land use patterns. 2) The establishment of ecological forests for public welfare should be addressed. Forests are important
219
in improving the ecological environment. There are few woodlands and low forest coverage in the southwest of Zhanjiang. The Leizhou Peninsula often suffers from water shortages. Therefore, demands for the development of forests, the establishment of ecological forests for the public good and improving the local ecological environment are very urgent. Natural reserved areas, forest parks, sources of rivers, reservoirs, coastal areas and other ecologically sensitive areas are recommended as the predominant areas for the establishment of public ecological forests. 3) Green corridors might be established. By planting forest and fruit trees and establishing grasslands, we can turn roads, river banks and railways into green corridors. 4) We must strengthen the management in combatting problems of soil erosion. Measures of planting and other engineering techniques could be adopted to prevent soil erosion, depending on local conditions.
References [1] Luo G F, Wu C F. Comparative study on urban land use efficiency. Economic Geography, 2003, 03: 367–369. (In Chinese) [2] Yuan L L. Analysis on the evolvement and problems of urban land use efficiency of Wuhan. Geography and Geo-information Science, 2006, 02: 92–96. (In Chinese) [3] Jiao Y F. Probing into the estimation of the economic benefit of urban land of Chongqing. Journal of Chongqing Normal University (Natural Science), 2006, 01: 76–79. (In Chinese) [4] Li M Y, Jiang H. An evaluation of land use effect in Guangzhou. Scientific and Technological Management of Land and Resources, 2005, 03: 36–38. (In Chinese) [5] Liu J, Huang X J, Zhai W X, et al. Studies on the spatial inequality of benefits of urban land use. Journal of Southern Yangtze University (Human and Social Science), 2005, 06: 67–71. (In Chinese) [6] Li Z B. A comprehensive evaluation method of urban land use efficiency. City Planning Review, 2000, 08: 62. (In Chinese) [7] Zhou T, Yang Q Y, Tan J, et al. An analysis on the evolvement of urban land use multiple efficiency of super cities’ accessory center regions. Journal of Southwest China Normal University (Natural Science Edition), 2004, 04: 686–690. (In Chinese) [8] Ma L Y, Zhan J M, Zhu Y F. Analysis on the economic benefit of land use and countermeasure research in Xinjiang. Journal of Shihezi University (Philosophy and Social Science), 2006, 01: 12–15. (In Chinese) [9] Peng J, Jiang Y Y, Li Z G, et al. Evaluation of land use efficiency. Resources and Environment in the Yangtze Basin, 2005, 03: 304–309. (In Chinese) [10] Costanza R, Arge R, Groot R, et al. The value of the world’s ecosystem services and natural capital. Nature, 1997, 387: 253–260. [11] Xie G D, Lu C X, Leng Y F, et al. Ecological assets valuation of the tibetan plateau. Journal of Natural Resources, 2003, 02: 189–196. (In Chinese) [12] Chen Q, Hu K, Luo K L, et al. Study on the synthetical assessment model of mine eco-environments based on AHP. Journal of China University of Mining and Technology, 2006, 03: 377–383. (In Chinese) [13] Chen Y G, Liu M H. The basic laws of the shannon entropy values of urban land use composition. Human Geography, 2001, 04: 20–24. (In Chinese) [14] Dou Q J. Study on ability of sustainable city development in Hebei Province. Journal of Shijiazhuang University of Economics, 2001, 05: 486–490. (In Chinese)
Journal of China University of Mining & Technology
Vol.17
No.2
J China Univ Mining & Technol 2007, 17(2): 0215–0219
Evaluation of Land-Use Efficiency Based on Regional Scale —A Case Study in Zhanjiang, Guangdong Province CHEN Shi-yin1,2, LIU Yao-lin1, CHEN Cui-fang1 1
College of Resources and Environmental Science, Wuhan University, Wuhan, Hubei 430079, China 2 College of Agriculture, Guangdong Ocean University, Zhanjiang, Guangdong 524088, China
Abstract: Evaluating land use efficiency is critical to the revision of general land use planning. An assessment indicator system for regional land use efficiency was established in this paper from the aspects of society, economy, ecology and environment. The weight of each indicator was defined by an analytical hierarchy process (AHP) and the entropy method (EM). Then, a case study in Zhanjiang was carried out to analyze the regional land use efficiency from 1996 to 2004 and its development by using the method of multifactor composite evaluation and an analytical model of the degree of coordination. The results indicate that land use efficiency with respect to society and the economy improved, whereas the ecological and environmental efficiencies were found to decrease. The degree of coordination in Zhanjiang is still at the status of basic coordination. Finally, measures for enhancing the ecological and environmental establishment are suggested in order to improve the regulations of land use structure and patterns, establish ecological forests for the public good and green corridors and prevent the soil erosion. Key words: regional scale; land-use efficiency; degree of coordination; evaluation CLC Number: F 301.24
1
Introduction
The purpose of land use is to achieve economic, social, ecological and environmental efficiencies, which ought to be the ultimate results of the utilization of land resources. Evaluation of land use efficiency is essential to the revision of general land use planning and land use regulations. It is expected that it will exert considerable effect on the promotion of sustainable land use as well as a sustainable development of society and the economy. Increased land use efficiency on the basic premise of our country during the progress of socio-economic development, has aroused unprecedented attention. China is a country with a vast population and a scarcity of land on a per capita basis. The contradiction between land and population is evident in the annual decrease in the area of cultivated land, so studies about how to evaluate land use efficiency is very popular in China[1–9]. While recent studies are mainly focused on the evaluation of urban and single land use efficiencies,
reports on multiple land use efficiency are few. In order to optimize and regulate the regional land use structure and revise the general regional land use planning, an assessment indicator system for regional land use efficiency is established in our paper, from the point of view of society, the economy, ecology and the environment. By applying the methods of an analytical hierarchy process (AHP) and an entropy method (EM), the weight of each indicator was defined. A case study in Zhanjiang was carried out to analyze the regional multiple land use efficiency and its evolution from 1996 to 2004 by means of a multifactor composite evaluation and an analytical model for the degree of coordination.
2 2.1
Evaluation Indicator and Process Principle
An indicator is a measure of evaluation of land use efficiency. The following principles should be ob-
Received 25 August 2006; accepted 28 September 2006 Projects 20055090032 supported by the Committees of Scientific and Technological Planning Project of Guangdong Province and 0512127 by the Natural Science Foundation of Guangdong Ocean University Corresponding author. Tel: +86-13828247596; E-mail address: [email protected]
216
Journal of China University of Mining & Technology
served when choosing indicators. 1) Scientific: indicators and their choice must be scientifically based. 2) Comprehensive: land use efficiency should be comprehensively and objectively represented. 3) Comparable: the meaning of indicators should be as uniform as possible. 4) Obtainable: indicator data should be accessible and credible. 5) Accurate: multiple land use efficiency should be clearly and exactly reflected. 6) Dynamic: indicators should be able to reflect future prospects and accommodate changes in the land use ecosystem. 2.2
Indicators
We established 24 evaluation indicators for multiple efficiency in regional land use from the aspects of society, economy, ecology and environment according to the principles listed above and the characteristics of regional social, economic development and land use ecosystems. 2.2.1 Economic efficiency in land use (X1) Economic efficiency in land use refers to labor consumption (including physical and intellectual labor) and the labor products or values according to social requirements. The main indicators are: land use ratio (X11), GDP per unit of land (X12), average GDP per person (X13), average constructive land per person Table 1
Garden land 1265.5
Climate control
787.5
1170.3
Headwater conservation
530.9
41.5
Erosion control
(yuan/hm2)
Water area
Residential area
Transportation land
Un-utilized land
707.9
－
－
－
－
796.4
407.0
－
－
－
707.9
18033.2
–6678
－
26.5
Woodland
Meadow
1902.5 1592.8 1769.7
－
796.8
796.8
102.9
－
3480
3480
－
Soil shape
1291.9
1291.9
2588.2
1725.5
8.8
－
－
17.7
Rubbish disposal
1451.2
722.1
1159.2
1159.2
16086.6
–2174.1
－
8.8
Biodiversity protection
628.2
16.6
1924.6
964.5
2203.3
－
－
300.8
Food yield
884.9
356.9
177
265.5
88.5
－
－
8.8
Raw materials produce
88.5
1145.4
1172.4
44.2
8.8
－
－
－
Recreation and culture
8.8
547.8
584
35.4
3840.2
－
－
8.8
6114.3
7354.8
13667.2
6509.4
40676.4
–5372.1
3480
371.4
Total
No.2
(X14), average farmland per person (X15), value of total industrial production per unit land (X16), value of total agricultural production per unit of land (X17), unit yield of food crop (X18), urbanization level (X19) and investment in fixed assets (X110). 2.2.2 Social efficiency in land use (X2) Social efficiency in land use refers to the degree of satisfaction in land use for social requirements and the effect of land use, including: population density (X21), ratio of self-sufficiency in food production (X22), proportion of land use for transportation (X23), Engel index (X24) and income per population (X25). 2.2.3 Ecological efficiency in land use (X3) Ecological efficiency in land use refers to the degree of effect and improvement of land use processes and the contribution to the maintenance of the ecological balance resulting from land utilization. Four indicators were adopted, which were the proportion of ecological land (X31), value of ecological services (X32), landscape diversity index (X33), degree of water and soil erosion (X34). 1) Value of ecological services Costanza et al. proposed a method for calculating the value of services of ecosystems in 1997 and Xie Gaodi et al have provided “the table of ecological service values of China’s ecosystem” based on the study by Costanza et al [10–11]. According to previous studies, we can obtain ecological service values of different land use types in Zhanjiang (Table 1).
Ecological service values of different land-use types
Cultivated land 442.4
Fume conditioning
Vol.17
Note: data from references [10] and [11].
2) Landscape diversity index We use as model the Gibbs-Mirtin’s diversity index to appraise landscape diversity:
GM = 1 −
n
∑ i =1
n
f i 2 /( ∑ f i ) 2
(1)
i =1
where GM represents the diversity index, fi denotes the area of different land types and n is the number of land types. 2.2.4 Environmental efficiency in land use (X4) Environmental efficiency in land use refers to the effects and changes of environment quality posed by
land utilization. Five indicators were selected: waste water per unit of industrial land (X41), exhaust emission per unit of industrial land (X42), waste residue per unit of industrial land (X43), fertilizer used per unit of cultivated land (X44) and pesticide used per unit of cultivated land (X45). 2.3
Process
2.3.1 Confirmation of weights Confirmation of weights of the multi-indicators is the key step of the evaluation process. Researchers have divided the methods of weight confirmation into
CHEN Shi-yin et al
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Evaluation of Land-Use Efficiency Based on Regional Scale
two types: subjective and objective methods. The subjective methods obtain the weights of indicators by subjective estimation according to the experts’ experience, such as Delphli and AHP [12]. Weights given by objective methods come from the actual indicator data, which are entirely objective and do not depend on subjective estimates, such as Principal Component Analysis (PCA) and EM. In our study, we applied the combined methods of AHP and EM to confirm the weights of indicators and the weights are presented as average values of these two methods. We have constructed five matrices based on the important degree of each indicator marked 1 to 9 according to the AHP and ranked them generally on an Table 2
individual basis, so we could obtain the weights of 24 evaluation indicators (Table 2), which could, as well, pass the consistency test. Regional land use efficiency evaluation is a sort of comprehensive evaluation with multiple indicators and the degree of difference between the indicators could be shown by information entropy. We could, therefore, adopt the entropy method to calculate the weights of evaluation indicators of regional land use efficiency (Table 2). Detailed calculations can be seen in references [7] and [13] with k=1/log2n＞0 (k is an adjustment coefficient).
Weights of evaluation indices of regional land-use efficiency
Indicators
X1
X2
X3
X4
X21
X22
X23
X24
X25
AHP
0.4373
0.2789
0.1206
0.1632
0.1534
0.1816
0.2566
0.2184
0.19
EM
0.4184
0.2073
0.1654
0.2092
0.1996
0.1999
0.2006
0.2
0.1999
Weights
0.4278
0.2431
0.143
0.1862
0.176 5
0.1908
0.2286
0.2092
0.1950
λmax = 4.0355; CI = 0.0118; RI = 0.90
λmax = 5.0028; CI = 0.0007; RI = 1.12
Indicators
X11
X12
X13
X14
X15
X16
X17
X18
X19
X110
AHP
0.0539
0.1329
0.1050
0.0678
0.0627
0.1360
0.0981
0.0776
0.0865
0.1795
EM
0.0988
0.1011
0.1002
0.0989
0.099
0.1018
0.1001
0.099
0.099
0.1022
Weights
0.0764
0.1170
0.1026
0.0833
0.0808
0.1189
0.0991
0.0883
0.0927
0.1409
Indicators
X31
X32
X33
X34
X41
X42
X43
X44
X45
AHP
0.2764
0.1943
0.1653
0.364
0.2732
0.1912
0.2623
0.1317
0.1416
EM
0.2498
0.2498
0.2498
0.2506
0.1991
0.201
0.2042
0.1982
0.1975
Weights
0.2631
0.2221
0.2076
0.3073
0.2362
0.1961
0.2333
0.1650
0.1696
λmax = 10.0201; CI = 0.00223; RI = 1.49
λmax = 4.0091; CI = 0.003; RI = 0.90
λmax = 5.0100; CI = 0.0025; RI = 1.12
Note: data from Zhanjiang statistics yearbook (2005); where λmax is the biggest characteristic root of matrix vector, CI is the consistency index and RI is the average Stochastic consistency index.
2.3.2 Indicator standardization Since the evaluation indicators of regional land use efficiency will be compared among different indices, they must be standardized. In order to make the result more accessible, an improved efficacy function was adopted [6], which is widely used in related studies
U A( X i )
⎧ X i − bi ⎪ a −b ⎪ i i =⎨ ⎪ ai − X i ⎪⎩ ai − bi
Positive efficacy
(2) Negative efficacy
where U A( X i ) represents the value of the efficacy function, Xi denotes the indicator, bi implies the lower limit of indicators (the minimum of all indicators in our paper) and ai implies the upper limit of indicators (the maximum of all indicators). 2.3.3 Efficiency index of multiple land use We obtained the regional land use multiple efficiency indices using the method of linear weighted sum (LWS) after calculating the efficiency values of the selected indicators and their individual weights. Therefore, the efficiency index of multiple land use
can be defined as follows: F = U1 ⋅ W1 + U 2 ⋅ W2 + " + U n ⋅ Wn = n
∑U
i
⋅ Wi
(3)
i =1
where F represents the efficiency index of multiple land use, Wi is the weight of indicator i and Ui denotes the efficacy value of the indicator. 2.3.4 Degree of coordination In essence, land use efficiency evaluation aims to obtain not only the index value of multiple land use efficiency but also the degree of coordination of each land use efficiency subsystem[9]. According to this systemic point, the degree of coordination of land use efficiency refers to the degree of consistency in each individual subsystem in the total ecosystem during the regional land use process. If the values of the degrees of coordination of each subsystem are close, the process of regional land use will be more harmonious. The degree of coordination of regional land use can be defined as follows:
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Journal of China University of Mining & Technology
Hi = 1 – Si / Mi (i =1, 2, 3, …, n)
3 Land-Use Efficiency Evaluation in Zhanjiang Zhanjiang is located in the southwest of Guangdong province (109°41′–110°58′E, 20°07′– 21°57′N), and bordered by the sea at the east, south and west. Administrative regions include two counties (Xuwen and Suixi), three county-level cities (Wuchuan, Lianjiang and Leizhou), four districts (Chikan, Xiashan, Potou and Mazhang), the Zhanjiang economic and technological development zone and the Donghaidao
4
Value indicators for evaluation land-use efficiency in Zhanjiang from 1996 to 2004
Index
1996
1997
1998
1999
2000
2001
2002
2003
2004
Economic
0.2274
0.2988
0.3846
0.3990
0.3423
0.3744
0.4948
0.5423
0.7538
Social
0.0680
0.2361
0.2954
0.5545
0.5436
0.5987
0.5496
0.6984
0.8345
Ecological
0.4852
0.5827
0.5618
0.5867
0.5822
0.6481
0.5435
0.4511
0.3858
Environmental
0.8591
0.6465
0.5554
0.4766
0.6850
0.5766
0.4233
0.4070
0.3154
Multiple
0.3431
0.3889
0.4201
0.4781
0.4894
0.5057
0.5019
0.5421
0.6392
Coordinate degree
0.1577
0.5381
0.7076
0.8334
0.7332
0.7808
0.8839
0.7546
0.5461
Development of Land-Use Efficiency
The changes in efficiency of the subsystems and multiple land use system are obvious in Zhanjiang from 1996 to 2004 (Fig. 1).
Fig. 1
No.2
economic development zone. There are 88 villages or towns, 31 neighborhood offices, 1501 village committees and 273 community neighborhood committees in 2004. It covers an area of 13225.4 km2 with a population of 7.159 million, of which the non-agricultural population is 1.915 million. The area is for 26.8 % urbanized. The population density is 574 persons/km2 and per capita land resources 0.18 hm2. In 2004, its GDP, in current prices, was 60.816 billion yuan with 8495 yuan per capita. We calculated the multiple land use efficiency indices and degrees of coordination after standardizing the original values of the evaluation indicators (Table 3): As the results show, the index of social efficiency was the highest in 2004 with a value of 0.8345 and the index of economic efficiency reached 0.7538, which reflects higher social and economic returns, but ecological and environmental efficiency were low, 0.3858 and 0.3154 respectively. The comprehensive land use efficiency index was 0.6392 with the value of 0.5461 for the degree of coordination of the ecosystem, showing that the ecosystem retained the status of basic coordination.
(4)
where Hi represents the degree of coordination, Si denotes the standard deviation of four indices and Mi is the average value of the four indices. The degree of coordination Hi is between 0 and 1 and the ecosystem will be more harmonious if this value is large. Generally, when Hi≥0.7, it indicates that each subsystem of regional land use ecosystem is highly harmonious while the ecosystem is in basic harmony with 0.4≤Hi＜0.7 and when Hi＜0.4 , the ecosystem is not harmonious[14].
Table 3
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Development of land-use efficiency in Zhanjiang from 1996 to 2004
There was a remarkable increase in economic efficiency and social efficiency, especially the social efficiency, which jumped from 0.068 to 0.8345 with the average annual growth ratio of 9.58%. However, the ecological and environmental efficiencies declined. A noticeable decrease was observed in environmental efficiency, which fell from 0.8591 to 0.3154 with average annual decline of 6.79%. The multiple efficiency was relatively stable, growing at a rate of 3.7%. From the point of view of the change of degree of coordination, there is no clear indication in the change of the degree of coordination. Between 1996 to 2004, the land use ecosystem, as measured by the degree of coordination,was very similar in 1997 and 2004. Except for 1996 when the degree of coordination was 0.1577, denoting a highly un-coordinated state, the degree of coordination in the other years remained fairly steady, especially in the years 1999 and 2002, when it reached a high level of coordination with the highest degree of coordination in the year 2002.
CHEN Shi-yin et al
Evaluation of Land-Use Efficiency Based on Regional Scale
5 Conclusion The results indicated that the social and economic efficiency of land use in Zhanjiang were high, while ecological and environmental efficiency became low, leading to a low degree of coordination of land use efficiency and a basic coordination status at present. Therefore, in order to ensure the sustainable use of land resources and sustainable socio-economic development, land use must be maintained in the context of social and economic efficiency and ecological and environmental establishment of land use should be strengthened. The following suggestions might be observed in the revision of general land use planning: 1) We must strengthen the adjustment of land use structures and patterns to ensure the implementation of returning farmland to forest and grassland projects and increase the diversity of land use patterns. 2) The establishment of ecological forests for public welfare should be addressed. Forests are important
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in improving the ecological environment. There are few woodlands and low forest coverage in the southwest of Zhanjiang. The Leizhou Peninsula often suffers from water shortages. Therefore, demands for the development of forests, the establishment of ecological forests for the public good and improving the local ecological environment are very urgent. Natural reserved areas, forest parks, sources of rivers, reservoirs, coastal areas and other ecologically sensitive areas are recommended as the predominant areas for the establishment of public ecological forests. 3) Green corridors might be established. By planting forest and fruit trees and establishing grasslands, we can turn roads, river banks and railways into green corridors. 4) We must strengthen the management in combatting problems of soil erosion. Measures of planting and other engineering techniques could be adopted to prevent soil erosion, depending on local conditions.
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