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Hydro-ecological impact of water conservancy projects in the Haihe River Basin
Acta Oecologica 44 (2012) 67e74
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Acta Oecologica journal homepage: www.elsevier.com/locate/actoec
Original article
Hydro-ecological impact of water conservancy projects in the Haihe River Basin Shanlong Lu a, Bingfang Wu a, *, Hao Wang a, Ninglei Ouyang a, Shuying Guo b a b
Institute of Remote Sensing Applications, CAS, No.1 Beichen West Road, 100101 Beijing, China Haihe River Water Resources Committee of China, 300170 Tianjin, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 January 2011 Accepted 13 July 2011 Available online 5 August 2011
Water conservancy projects are commonly constructed with different purposes. This usually results in improved flooding control, but may lead as well to environmental problems, such as river dry up, river morphology change, and reduction in biodiversity. The present study considers water conservancy projects in the Haihe river basin, following the major flood in 1963. It maps the water projects as well as the surface water bodies in 1964, 1980 and 2004, by using an integrated method of remote sensing and field surveys. The impact of the water conservancy projects on the hydro-ecological processes and the ecological environment is analyzed. Construction of the controlled reservoir resulted in a sharp drop of the river discharge and sediment. It also resulted in a reduction of river infiltration, an increase of evaporation and a change in regional water balance characteristics. Furthermore, the projects separated the hydraulic connection between upstream and downstream areas, weakened the river’s natural connectivity, and changed the dynamic conditions of the river water. On the basis of the study, we propose changing the operation mode of the existing controllable water conservancy projects and removing the projects with degraded and unreasonable functions as two optional ways to resolve the hydro-ecological problems of the basin. Ó 2011 Elsevier Masson SAS. All rights reserved.
Keywords: Runoff Sediment River infiltration Water surface evaporation Channel connectivity Flow continuity Biological diversity
1. Introduction The construction of water conservancy projects after major flooding can be guided by various purposes. We distinguish four categories, all leading to water management projects. When combined, these projects have as a common aim to protect human life and property, and to provide water and electricity, flood control and recreation services. The first purpose is to protect residential areas from the threat of floods and it requires establishment of levees, flood channels and flood catchments. The second purpose is to develop shipping facilities and industrial and agricultural production. It is mainly achieved by dredging activities and the construction of river channels. The third purpose is the intercept and transfer of available water. It can be achieved by the construction of reservoirs and water diversion projects. The fourth purpose is to meet the needs of leisure and entertainment, which leads to the construction of sluices and dams. Such projects, however, also lead to significant changes to the river ecological environment: river dikes cut off the relationship between river flood plains and river channels, and reduce wetland habitats, shipping and water recreational activities squeeze the space for
* Corresponding author. E-mail address: [email protected] (B. Wu). 1146-609X/$ e see front matter Ó 2011 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.actao.2011.07.003
aquatic organisms, river bank protection works reduce the area of aquatic habitats, and reservoirs and the water transfer projects change the spatial and temporal pattern of regional water resources. Among these, the environment that seriously damaged by dam construction and the dam-related activities (such as irrigated agriculture and water entertainment), resulting in a serious reduction in freshwater biodiversity. Currently, more than 60% of the world’s major rivers are subject to hydrological management. The wetlands were drained into agricultural land, and many fish stocks were plummeted (Zhou et al., 2007). In China, facing the increasingly serious environmental problems, the government has begun to improve upon the river management measures that have been used in previous years. Reflection on sustainable river management by making room for the river through protection and restoration of the natural river flow and of river hydrological processes, is gradually being accepted and practiced (Jiang et al., 2006; Rohdea et al., 2006). As a comparison, in the United States, nearly 500 dams have been removed to restore the natural fish populations and to reduce the harm to the local residents’ lives and property, caused by dams (Sparks et al., 2000). In order to prevent flood damage, improve watershed environmental quality, and to give more room for the river, the Netherlands proposed a series management measures called “Room for the river”, leading to broadening and deepening river channels, cleaning up the non-water conservancy facilities on
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the river bed and dredging the marshes and puddles at both sides of the rivers (Arnhem, 2006). Haihe River is one of the China’s seven major river systems. It has been subject to big changes during the last 2000 years. Changes to the two main subsidiaries, i.e. Weihe River, Zhanghe River, and the Hutuohe River in the south of the basin started as early as the Han Dynasty (1st century AD). Changes to the Yongdinghe River and the Jiyunhe River in the north of the basin, resulting in muddy rivers, started in the middle Min Dynasty (13th century AD) (Tan, 2002). To overcome the negative influence on the production and life caused by the river water regime in different stages, different management measures were taken. The Yongdinghe River, for example, experienced three significant changes on the management and development. During the Three Kingdoms period up to the Sui and Tang Dynasties, the river was mainly developed for irrigation and navigation, during Liao and Jin Dynasties to Min and Qing Dynasties the main management activities is dike construction, whereas during the years of the Republic of China, no maintenance was applied to the river due to the economic and social turmoil (Li, 2005). Since the founding of the People’s Republic of China, especially after the 1963 flood disaster in the Haihe River Basin, large-scale water conservancy projects have been constructed, in order to solve the long-term problems of flood disasters to the production and life of the basin, including reservoirs, man-made channels, ditches and dikes. Until 1980, a flood control and drainage system has been established, leading to a successful change in the frequent flooding. With the construction and implementation of the water conservancy projects, however, the basin environment has been degraded gradually (Haihe River Water Resources Committee, 2004). At present, the conflict of water supply and demand among socioeconomic development, production and living, and eco-system health is prominent. Development of water resources and utilization of the whole basin has increased above 120% (Zhang et al., 2008). The ecological environment is thus drying, following the reduction of the surface water, the continually groundwater level decline, and the increased surface and groundwater pollution (Yao, 2003). The objective of this study is to clarify the impact characteristics of the water conservancy projects construction on the hydrological regime and eco-environment, and to analyze the key processes of the eco-environment degradation. To do so, we use an integrated method of remote sensing and field surveys, and obtain the change information of the water conservancy projects and the surface water bodies in 1964, 1980 and 2004. This allows us to analyze the impact of the establishment of water conservancy projects on parameters of the hydro-ecological processes, such as river runoff and sedimentation, river infiltration capacity, water surface evaporation, river connectivity and biodiversity. The study proposes measures to adjust the function and spatial distribution pattern of the regional hydraulic projects. 2. Study area The Haihe River Basin is located in the Hebei Province in China, and contains the two major cities of Beijing and Tianjin; parts of Inner Mongolia autonomous region, and then Shanxi, Henan, Liaoning and Shandong Provinces. The catchment covers an area of 318,000 km2. The northwestern part of the basin has a higher elevation than the southeastern part. The basin receives its water in the west from the Shanxi Plateau and Taihang Mountains, and in the north from the Mongolia Plateau and the Yanshan Mountains. The area of the mountains accounts for 60% of the total basin area, whereas plains in the east and southeast account for 40% of the total basin area. The basin includes three river systems: the Haihe River, the Luanhe River, and the Tuhai-Majia River. Among these, the Haihe River is the major river system. It stretches between 111.96 and
118.48 E longitudes and between 35.00 and 41.61 N latitude (Fig. 1), and is composed of the Jiyunhe River, the Chaobaihe River, the Beiyunhe River, and the Yongdinghe River in the north of the basin, and the Daqinghe River, the Ziyahe River, the Zhangweihe River and the Heilongguangyundong River in the south of the basin, with an area of 234,600 km2. The study region belongs to the East Asian monsoon climate of the temperate zone with four distinct seasons. The annual average temperature is 1.5 e14 C, and the annual average relative humidity is 50%e70%. The average annual rainfall is 539 mm (calculated using the 1956e2000 rainfall series), concentrated mostly during the flood season from June to September (Editor Board of Haihe Records, 1997). The total population of the study area equals 109.55 million in 2007, accounting for 8.5% of the total population of China. Of these, 41.35 million (37.7%) live in cities. 3. Data and methodology In this study, the hydro-ecological impact analysis of the water conservancy projects construction has been divided into two parts. The first part is to assess the hydrological and ecological parameters in a quantitative way. This concerns information extraction of river runoff, sediment from hydrological yearbooks and extraction of hydraulic engineering numbers and river morphological changes from satellite remote sensing images and field surveys. The second part is to quantitatively characterize hydro-ecological processes. This will be based on the changes of surface water bodies (Tweed et al., 2009), river connectivity (Bednarek, 2001), and biodiversity. 3.1. Data sources The Haihe River Basin Hydrological Yearbooks (1954e2000) are used to obtain the river runoff and sediment data. The CORONA KH4A (resampled to a spatial resolution of 7.5 m) and CORONA KH-9 (resampled to a spatial resolution of 9 m) spy satellite images acquired in 1964 and 1980, and the SPOT 5 images (spatial resolution 2.5 m) in 2004 were used to map the hydraulic engineering. In addition, the KH-4A images of 1964, the Landsat MSS (57 m resolution) images of 1980, and the Landsat TM (30 m resolution) images of 2004 are used to map the changed surface water bodies. 3.2. Field survey The survey area covers the 5 sub-basins of the Chaobaihe River, Yongdinghe River, Daqinghe River, Ziyahe River, and ZhangWeihe River, including 28 rivers, 16 reservoirs, 7 flood catchments, 6 water control projects and 90 small-scale water conservancy projects. The purposes of field survey are establishing the satellite remote sensing image interpretation symbols and investigating the river channel morphological changes around the hydraulic engineering structures. Before the survey, some default field survey regions were based on the SPOT 5 satellite images. During the survey, the handheld GPS was used to obtain the precise position of each observation point. The relative positions between the observation points and the hydraulic engineering structures (their types, size, functions and conditions), the hydraulic contact between upstream and downstream of the project, the surrounding ecological environment, and land use were recorded. 3.3. Satellite remote sensing monitoring 3.3.1. Water conservancy project interpretation Referenced to the field survey photos and the SPOT 5 satellite images, the spatial distribution of the water conservancy projects
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Fig. 1. Location of the study area in northeast China.
including reservoirs, dams, and sluices in 2004 was mapped, using visual interpretation. Similarly, water conservancy projects constructed in 1964 and 1980 were mapped from the CORONA KH-4A and CORONA KH-9 spy satellite images. 3.3.2. Surface water body mapping The K-Means unsupervised classification method was used to map surface water body from the grey-scaled CORONA KH-4A images, whereas incorrectly mapped water body boundaries and polygons were manually modified. Fig. 2 presents the integrated water body mapping method combining the Normalized Difference Water Index (NDWI) (McFeeters, 1996) and the slope data to map water bodies from the 1980 Landsat MSS images. The NDWI was used to extract the initial water body boundaries, and the slope data generated from the digital DEM were used to eliminate the influence of the mountain
Fig. 2. Water body mapping method for Landsat MSS images.
shade (Lu, 2008). During mapping, the histogram of each NDWI images was used to obtain the threshold (T1) between water bodies and other features. Thresholds for the NDWI images of the study area range from 0.1 to 0.5. Similarly, a slope threshold of 10 was used to eliminate the influence of the mountain shade (Lu, 2008). Then the final accurately distributed water bodies were mapped. For water body mapping with Landsat TM images, we combined the Modified Normalized Difference Water Index (MNDWI) (Xu, 2005), the Tasseled Cap Wetness Index (TCW) (Huang et al., 2002), and slope data (Fig. 3). The MNDWI extracts the initial water body boundaries, the TCW enhances the accuracy of the shallow water wetland boundary extraction (Ouma and Tateishi, 2006; Ordoyne and Friedl, 2008), and the slope data eliminates
Fig. 3. Water body mapping method for Landsat TM images.
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the influence of the mountain shade (Lu, 2008). The histogram of each MNDWI images provided the threshold (T3) between water bodies and other features. Thresholds for all MNDWI images within the study area range from 0.2 to 0.2. A TCW threshold equal to 0 was used to distinguish the boundaries between water and sediment mixing zone as the values of the water bodies are less than 0 in the TCW images. Finally, a slope threshold of 10 was used to eliminate the influence of the mountain shade (Lu et al., 2011).
being mainly constructed before 1964. The medium-sized reservoirs increased evenly, with 39 reservoirs constructed before 1964, 38 during the period of 1964e1980, and 30 between 1980 and 2004. The number of small reservoirs also increased. There are 399, 406, and 349 small reservoirs built in the three period of time, respectively. River dams, rubber dams, and sluices, were mainly constructed after 1980 (Table 1). 4.2. The hydro-ecological impact of the water conservancy projects
3.4. Hydro-ecological impact characterization The parameters of river infiltration, surface water evaporation, river connectivity and flow continuity were used to quantitatively characterize the hydro-ecological impact from the water conservancy projects of the study area. River infiltration plays an important role on maintaining the river ecological water balance. The infiltration changes caused by river water changes were calculated with the following formula:
Ds ¼
ðst s0 Þ t
(1)
DV ¼
1 t ðt þ 1Þ D s 365 s 2
(2)
where Ds is the change of the average annual river water area (km2), st and s0 are the river water area at the starting and ending time (km2), DV is the total changed volume of the river infiltration (m3), s is the permeability coefficient (m yr1), and t is the calculation time period. The changed surface water will influence the evaporation of the basin, and have an impact on the regional water resources (Tian et al., 2005). The evaporation water losses caused by surface water changes can be calculated by the formula (3):
1 2
D E ¼ E t s0 ðt þ 1Þ D s
(3)
where DE is the total evaporation water loss in the study period (m3) and E is the average annual pan evaporation (m). The conversion factor between the pan evaporation and actual evaporation equals 0.7 0.2 (Tweed et al., 2009). River connectivity (Rcon) is a key indicator to reflect the river habitat conditions. It equals the ratio of the total quantities (Dn) of the reservoirs, rubber dam, and sluices and the total length of the river (Rl). The formula is as follows:
Rcon ¼ Dn =Rl
(4)
A large Rcon value corresponds with a low channel connectivity. Flow continuity (Fcon) is the basis for the river hydrological continuity, nutrient delivery, and biological community continuity. It is calculated as the ratio of the river channel with water (Wl) and the total length of the river (Rl):
Fcon ¼ Wl =Rl
4.2.1. Changed river runoff Between 1964 and 2004, the average annual pan evaporation and precipitation of Haihe River Basin was equal to 1100 mm and 539 mm, respectively. As evaporation exceeds by far the precipitation, the construction of the water conservancy projects will reduce the river runoff. Monitoring of the runoff data from the Water Conservation Centre of Haihe River Water Resources Committee shows that the average annual runoff to the Suzhuang gauging Station reduced from 2.93 109 m3 to 0.95 109 m3, after construction of the Miyun Reservoir in 1960 (Fig. 4). The river runoff in other sub-basins also changed with the construction of the upstream water conservancy projects. In Fig. 5, the separation point of the precipitation and runoff downward curves indicates the starting point of an abrupt runoff change in each sub-basin. Such a significant changing time of the average annual runoff coincides with the time for the water conservancy project construction. For the Yongdinghe River Basin, changes in runoff are related with construction of the Guanting Reservoir between 1951 and 1954. The northern and southern Daqinghe River Basin is mainly controlled by the Wangkuai Reservoir and Xidayang Reservoir, built between 1958 and 1960. The Hutuohe River Basin is mainly impacted by the construction of the Huangbizhuang Reservoir and Gangnan Reservoir between 1958 and 1960. And the Fuyanghe River Basin is mainly controlled by the construction of the Dongwushi Reservoir between 1958 and 1959 (Table 2).
(5)
A large Fcon values indicates a high flow continuity. 4. Results 4.1. The changes of the water conservancy projects construction Interpretation of the satellite remote sensing images of 1964, 1980, and 2004 shows that the number of water conservancy projects dramatically increased during the last 40 years. The reservoirs number increased from 462 to 1287, the large reservoirs
4.2.2. Reduced sediment transfer The construction of the large number of water conservancy projects resulted in substantial blocking of sediment. At the end of 2000, most small reservoirs upstream of the Guanting Reservoir have already overwhelmed. The total deposit volume is 147 106 m3, whereas the total deposit volume for the large and the medium-sized reservoirs equals 441 106 m3 (Liu and Hu, 2004). For the Miyun Reservoir, for example, the average annual sediment transferred to the Suzhuang gauging station reduced from 907.8 tons to 40.7 tons, accounting for a 95.5% reduction, immediately after building the reservoir in 1960 (Fig. 4). 4.2.3. Decreased river infiltration volume From previous studies (Fan et al., 2008; Hu et al., 2009) we know that the average permeability coefficient of the Haihe river bed ranges between 0.0347 and 0.21 m day1. The changed infiltration volume caused by the changed river water area in different periods is calculated using equations (1) and (2) and taking the minimum average permeability coefficient of 0.0347 m day1 and the three Table 1 Water conservancy projects constructed in 1964, 1980, and 2004. Year
Water conservancy projects (Quantities) Reservoir
1964 1980 2004
Dam
Large
Medium
Small
River dam
Rubber dam
24 26 26
39 77 107
399 805 1154
11 12 346
0 0 59
Sluice
Total
33 69 481
506 989 2173
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Fig. 4. The runoff and sediment data measured on the Suzhuang gauging station downstream of the Miyun Reservoir (The data is provided by the Water Conservation Centre of Haihe River Water Resources Committee).
phases from Table 3 as the basic data. For the period from 1964 to 1980, the total volume of the infiltration reduction caused by the reduced river water area is 73.09 109 m3 and the average annual decrease is 4.57 109 m3. From 1980 to 2004, the total volume of the infiltration reduction is 140.44 109 m3, with an average annual decrease of 5.85 109 m3. 4.2.4. Increased reservoir surface water evaporation water loss The total evaporation water loss of the reservoir surface water was calculated with the formula (3), using the 1952e2001 time series pan evaporation data and taking the three phases from
Table 3 as the basic data. The results show that from 1964 to 1980, the total reservoir evaporation water loss is between 12.86 109 m3 and 23.15 109 m3 and the average annual evaporation water loss is between 0.8 109 m3 and 1.45 109 m3. Between 1980 and 2004, the total evaporation water loss is between 15.33 109 m3 and 27.6 109 m3, with an average annual evaporation water loss between 0.64 109 m3 and 1.15 109 m3. 4.2.5. Changed river connectivity and flow continuity From 1964 to 2004, the connectivity of the Yongdinghe River, Chaobaihe River, Daqinghe River, Ziyahe River, and Zhangweihe
Fig. 5. Changes in the average annual precipitation and runoff of the Yongdinghe River Basin, the north of the Daqinghe River Basin, the south of the Daqinghe River Basin, Hutuohe River Basin, and Fuyanghe River Basin obtained by using the Mann-Kendall method (Liu et al., 2004). The thick solid line represents the precipitation, whereas the thin solid line represents the runoff. The vertical axis represents the sequential values of the statistic U(t) calculated with the Mann-Kendall method.
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5. Discussion
Table 2 Construction periods for several large reservoirs in Haihe River Basin. Basin
Reservoir
Construction period
Yongdinghe River Basin The north of the Daqinghe River Basin The south of the Daqinghe River Basin Hutuohe River Basin
Guanting Reservoir Xidayang Reservoir
1951e1954 1958e1960
Wangkuai Reservoir
1958e1960
Huangbizhuang Reservoir Gangnan Reservoir Dongwushi Reservoir
1958e1959
Fuyanghe River Basin
1958e1959
Table 3 River and reservoir surface water area in different time period (km2). Period
1964
1980
2004
River surface water area Reservoir surface water area
1928.1 1582.9
1249.2 1348.8
362.1 985.0
River decreases gradually. Before 1980, the Zhangweihe River has a higher connectivity than the Chaobaihe River and the Ziyahe River, whereas the Daqinghe River has a higher connectivity than the Yongdinghe River. At the end of 2004, the river with the lowest connectivity is the Chaobaihe River, followed by the Yongdinghe River, the Daqinghe River, the Zhangweihe River and the Ziyahe River. In the same period, the flow continuity of the Yongdinghe River, the Daqinghe River, and the Ziyahe River continuously decreases. The Chaobaihe River experienced a gradual recovery after years of connectivity decrease, whereas such a decrease occurred for the Zhangweihe River after 1980 (Table 4). 4.2.6. Reduced biodiversity Restrictions by available data, fish species in the wetlands are chosen as an indicator to reflect the biodiversity changes. Since 1960s, the fish species in the wetland are greatly decreased. Before the 1960s, the Qilihai wetland as a natural spawning field for the anadromous fish contained more than 30 fish species. After the mid 1970s, these fish species have become extinct (Wang et al., 2005). Similar conditions occurred to the Baiyangdian wetland, another wetland area in the Haihe River Basin, also called the Pearl of the North China Plain. From 1958 to 1998, the number of fish species in the Baiyangdian wetland sharply declined. Thereafter, the number slowly increased (Fig. 6).
In the past, the managers and scientists have had a widespread concern on hydro-ecological impacts caused by the construction of the water conservancy projects (Xu, 2004; Wang et al., 2005; Zhao et al., 2007; Yang and Tian, 2009). Usually, the river runoff and sediment deposition have been taken as the key indicators for analyzing the environmental changes and the impact of the human activities (Zhang et al., 2006; Fiener and Auerswald, 2006; Wang et al., 2008). Regional water resources distribution, however, as well as the hydrologic connectivity and continuity are rarely considered, because of scarcity of the data. With the help of satellite remote sensing images, this paper quantified the two important types of hydro-ecological parameters. Although, the infiltration in the agricultural land that irrigated by river water was not considered in the river infiltration and surface water evaporation calculation, and the impact of the acquisition time difference of the remote sensing images on surface water mapping was not considered in the river connectivity and flow continuity characterization, these quantitative data provide new way for river hydroecological process research. The main purpose of the Haihe River water conservancy projects construction has been flood controlling and irrigation (Wu and Lu, 2011). Potential floods can now be blocked and water resources can be stored, thus forming a basis for the water conservancy projects. During the past 40 years, however, there have been no large-scale floods, except for the storm floods in the south of the Haihe River Basin in 1996 (Yang et al., 2005). Therefore, many of the water conservancy projects have long been operated with a low or even negative efficiency. They have had a serious impact on the efficiency of using water resources for animal life, production and ecological requirements. The reservoirs constructed in the upstream stopped the fish moves down the river, and the construction of dam in the downstream cut off the anadromous migration channels for fishes. Which make many fish species came to extinct. For example, the water interception and water transfer from the upstream reservoirs of Baiyangdian wetland caused large changes in fish species diversity and in their quantities (Zhao et al., 2007). And the tide keeping sluice, constructed at the end of the 1960s and the early 1970s, resulted in a yearly decrease of anadromous fish species in Qilihai wetland (Wang et al., 2005). Furthermore, the decreased water yield and increased water pollution caused by climate
Table 4 Parameters of the river connectivity and the flow continuity in sub-basins of the Haihe River Basin.a Year
Sub-basin
River length (km)
Water conservancy projects (number)
River length with water (km)
River connectivity (number/km)
Flow continuity
1964
Yongdinghe River Chaobaihe River Daqinghe River Ziyahe River Zhangweihe River Yongdinghe River Chaobaihe River Daqinghe River Ziyahe River Zhangweihe River Yongdinghe River Chaobaihe River Daqinghe River Ziyahe River Zhangweihe River
920 777 474 1166 1337 920 777 474 1443b 1337 920 777 474 1443b 1337
16 8 5 12 5 43 19 18 22 10 104 105 50 74 84
751.9 685.2 448.4 1164.1 1082.5 619.2 557.7 419.3 1206.6 1148.9 610.4 616.5 230.0 947.7 449.0
0.017 0.010 0.011 0.010 0.004 0.047 0.024 0.038 0.015 0.007 0.113 0.135 0.105 0.051 0.063
0.818 0.882 0.946 0.998 0.810 0.673 0.718 0.884 0.836 0.860 0.664 0.794 0.485 0.657 0.336
1980
2004
a The rivers in each sub-basins: Yongdinghe River Basin (Yongdinghe River, Yongdingxinhe River, Yanghe River, Sangganhe River, Guishuihe River), Chaobaihe River Basin(Chaobaihe River, Chaohe River, Baihe River, Chaobaixinhe River), Daqinghe River Basin(Daqinghe River, Duliujianhe River, Haihe River, Baigouhe River, Zhongtinghe River, Zhaowangxinhe River, Caohe River), Zhangweihe River Basin(Zhangweixinhe River, Weiyunhe River, Zhanghe River, Zhuozhanghe River, Qingzhanghe River, Weihe River, Nanyunhe River), Ziyahe River Basin(Hutuohe River, Fuyanghe River, Ziyahe River, Fuyangxinhe River, Ziyaxinhe River). b It includes the length of the two canals namely Fuyangxinhe River and Ziyaxinhe River that were excavated between 1965 and 1967.
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Fig. 6. The number of fish species in the Baiyangdian Wetland from 1958 until 2007 (Zhao et al., 2007).
change, land and tourism development also increased the reduction of the fish resources (Cao et al., 2003). From 1964 to 2004, the reservoir surface area of the basin gradually reduced, with a total reduction equal to 597.9 km2 (37.8%) (Table 3). Many of the dried up reservoirs in the basin have lost their original function (Fig. 7) as they not only did not play the role of water reserving, but also blocked runoff formation from precipitation, increased the evaporation water loss, and consequently have an impact on rainfall supplies to the downstream rivers. The estimation results in sub-sections 4.2.3 and 4.2.4 show that the basin water resources loss due to the reservoir water reserving and reduction of the river runoff reaches to 52.1 109 to 73 109 m3 per year. This value is equivalent to 56%e78% of the water requirement that should be transferred from outside of the basin (Zhang et al., 2003). In addition, small hydraulic engineering constructions such as river dam, rubber dam and sluices to meet water demand for the local agricultural production, daily life and recreation (Fig. 8, September 15th, 2008), exacerbated the regional hydro-ecological environment degradation. They cut off the river flow into different parts, thus increasing the evaporation and blocking migration routes of fish (Wang et al., 2005). Therefore, for water conservancy projects with degraded or unreasonable functions, changes in the operation mode (Zheng et al., 2005) or removing the projects (Graf, 2002) could be reasonable choices. This may alter negative impacts on river water dynamic conditions and water resources distribution. To return to the original conditions of the natural river flow, existing
Fig. 8. The concrete river dam (top) and rubber dam (bottom) in the Chaobaihe River Basin.
controllable engineering facilities could be used. This could lead to a new operation mode of storing water in flooding time, releasing it in the dry season. This may help to restore the river flow dynamics, and ensure a minimum instream ecological flow (Liu et al., 2010). In this sense, the function of the existing water conservancy projects should be evaluated, both from the point of view of engineering operation efficiency and from a sustainability point of view. Projects with degraded and unreasonable functions, such as abandoned reservoirs and small flow engineering blocks, should then be removed. In this way, the longitudinal river connectivity, and the vertical and lateral water exchange in the river channel can be restored. Engineering practices and researches in last decade already indicate that dam removal is an effective river restoration method (Bednarek, 2001; Schmitz et al., 2009). In the study period, the changing patterns of river connectivity and flow continuity are different in different sub-basins. Different
Fig. 7. Change detection of the Baohe Reservoir in the Daqinghe River Basin.
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control measures should have been installed to protect or restore the river hydro-ecological environment. For the Yongdinghe River Basin, the Daqinghe River Basin, and the Ziyahe River Basin, restoration of the flow continuity by changing the operation mode of the existing water conservancy projects could be good choices at present. For the Chaobaihe River Basin, under the premise of maintaining the growth trends of the flow continuity, removal of some small hydraulic engineering constructions (Fig. 8) may be an attractive way to restore aquatic biodiversity. Because there are some reservoirs including another large reservoir will be built upstream of the Zhangweihe River Basin (Department of Hebei Water Resources, 2007) in the near future, for the Zhangweihe River Basin, stopping or reducing the planned water conservancy projects construction is most likely the best option. 6. Conclusions The construction of the water conservancy projects greatly changed the hydrological characteristics of the Haihe River. During the period of 1951e1960, influenced by the controllable reservoir construction in each sub-basin, the discharge and sediment flow downstream to all the rivers sharply declined. The changed water surface area of the rivers and reservoirs resulted in the reduction of the river infiltration and increasing of the water surface evaporation. This, in turn, changed the regional water balance of the basin. In addition, water conservancy projects blocked the hydraulic connection between upstream and downstream, and destroyed the river’s natural connectivity. Which resulted in the decreasing of the fish species. On the basis of this study, we propose of changing the operation mode of the existing projects and removing the projects with degraded and unreasonable functions as the two optional ways to solve the current hydro-ecological environmental problems in the basin. Acknowledgments We would like to acknowledge the financial support of the Key Innovation Project of the Chinese Academy of Sciences (KZCX1-YW08-03, KSCX1-YW-09-01). Thanks to the Haihe River Water Resources Committee of China for providing the archived SPOT 5 images. We also thank the National Data Sharing Network of Earth System Science (www.geodata.cn) and the U.S. Geological Survey Data Sharing Network (http://glovis.usgs.gov) for providing the Landsat MSS/TM/ETMþ images. References Arnhem, M.A.W., 2006. Spatial Planning Key Decision ‘Room for the River’. http:// www.ruimtevoorderivier.nl (12.01.09). Bednarek, A.T., 2001. Undamming rivers: a review of the ecological impacts of dam removal. Environmental Management 27, 803e814. Cao, Y.P., Wang, W., Zhang, Y.B., 2003. Present situation of fish stocks in Baiyangdian Lake. Chinese Journal of Zoology 38, 65e68. Department of Hebei Water Resources, 2007. Flood Control Planning in Hebei Province. http://www.cjw.com.cn/index/detail/20071219/98310.asp. Editor Board of Haihe Records, 1997. Haihe Records, vol. I. China Water Power Press, Beijing, China. Fan, X.M., Liu, G.H., Shu, L.C., Liu, Q.S., 2008. Field measuring the hydraulic conductivity of different sediments in Yellow River Delta. Journal of Water Resources & Water Engineering 19, 6e10. Fiener, P., Auerswald, K., 2006. Seasonal variation of grassed waterway effectiveness in reducing runoff and sediment delivery from agricultural watersheds in temperate Europe. Soil & Tillage Research 87, 48e58. Graf, W.L., 2002. Dam removal research status and prospects. In: Proceedings of The Heinz Center’s Dam Removal Research Workshop October 23e24, 2002. The H. John Heinz III Center for Science, Economics and the Environment. http://www. heinzctr.org. Haihe River Water Resources Committee, 2004. Water Resources Protection Plan for the Ecological Environment Restoration of Hai Basin.
Hu, J.F., Wang, J.S., Teng, Y.G., Yang, Y.Q., 2009. Experiment 0f permeability of riverbed sediment in the Yellow River. Hydrogeology and Engineering Geology 3, 25e28. Huang, C.Q., Wylie, B., Yang, L.M., Homer, C., Zylstra, G., 2002. Derivation of a tasseled cap transformation based on Landsat 7 at satellite reference. International Journal of Remote Sensing 23, 1741e1748. Jiang, L.G., Yu, X.B., Li, L.F., 2006. In: Smits, A.J.M., Nienhuis, P.H., Leuven, R.S.E.W. (Eds.), New Approaches to River Management. Science Press, Beijing, China. Li, H.Y., 2005. Development and restoration history analysis of Yongdinghe River. Beijing Water Resources 6, 56e57. Liu, C.Z., Liu, Z.Y., Xue, Z.H., 2004. Study of trends in runoff for the Haihe River Basin in recent 50 years. Journal of Applied Meteorological Science 15, 385e393. Liu, C., Zhao, C., Xia, J., Sun, C., Wang, R., Liu, T., 2010. An instream ecological flow method for data-scarce regulated rivers. Journal of Hydrology. doi:10.1016/ j.jhydrol.2010.11.026. Liu, S.H., Hu, C.H., 2004. The calculation of the soil held up by the soil and water conservation project in Guanting Reservoir catchment, in the last 20 years. Journal of Sediment Research 2, 67e71. Lu, S.L., 2008. Numerical Environment Modeling of Jinqu Basin Based on the Geological Factors. PhD Dissertation, Zhejiang University, China. Lu, S.L., Wu, B.F., Li, F.P., 2011. Wetland pattern change in Hai Basin. Journal of Remote Sensing 15, 349e371. McFeeters, S.K., 1996. The use of normalized difference water index (NDWI) in the delineation of open water features. International Journal of Remote Sensing 17, 1425e1432. Ordoyne, C., Friedl, M.A., 2008. Using MODIS data to characterize seasonal inundation patterns in the Florida Everglades. Remote Sensing of Environment 112, 4107e4119. Ouma, Y.O., Tateishi, R., 2006. A water index for rapid mapping of shoreline changes of five East African Rift Valley lakes: an empirical analysis using Landsat TM and ETMþ data. International Journal of Remote Sensing 27, 3153e3181. Rohdea, S., Hostmannb, M., Peter, A., Ewald, K.C., 2006. Room for rivers: an integrative search strategy for floodplain restoration. Landscape and Urban Planning 78, 50e70. Schmitz, D., Blank, M., Ammondt, S., Patten, D.T., 2009. Using historic aerial photography and paleohydrologic techniques to assess long-term ecological response to two Montana dam removals. Journal of Environmental Management 90, S237eS248. Sparks, R.E., Braden, J., Demissie, M., Mitral, P., Schneider, D., White, D., Xia, R., 2000. Technical support of public decisions to restore floodplain ecosystems: a status report on the Illionis river project (USA). In: Smits, A.J.M., Nienhuis, P.H., Leuven, R.S.E.W. (Eds.), New approaches to river management. Backhuys Publishers, Leiden, pp. 225e247. Tan, X.M., 2002. Water environment evolution and impact of Haihe River Basin. Water Resources Development Research 2, 15e20. Tian, J.H., Cui, Q., Xu, J.H., Zhou, X., 2005. Water surface evaporation impact on water resources of large and middle reservoirs in the Yellow River valley. Journal of Shandong Agricultural University (Natural Science) 36, 391e394. Tweed, S., Leblanc, M., Cartwright, I., 2009. Groundwater-surface water interaction and the impact of a multi-year drought on lakes conditions in South-East Australia. Journal of Hydrology. doi:10.1016/j.jhydrol.2009.09.043. Wang, G.Q., Zhang, J.Y., He, R.M., Jiang, N.Q., Jing, X.A., 2008. Runoff reduction due to environmental changes in the Sanchuanhe river basin. International Journal of Sediment Research 23, 174e180. Wang, Z.W., Liu, M.D., Li, Z.J., Lu, S.S., 2005. Degeneration characteristics and rehabilitation of Qilihai wetland environment ecological system. Research of Soil and Water Conservation 12, 244e247. Wu, B.F., Lu, S.L., 2011. Watershed remote sensing: methodology and a paradigm in Hai Basin. Journal of Remote Sensing 15, 201e223. Xu, H.Q., 2005. A study on information extraction of water body with the modified normalized difference water index (MNDW1). Journal of Remote Sensing 9, 589e595. Xu, J., 2004. A study of anthropogenic seasonal rivers in China. Catena 55, 17e32. Yang, P., Yu, Y., Yang, M., Cheng, B.F., 2005. The “63.8” and “96.8” floods in south of the Haihe River Basin. Hebei Water Resources 1, 1e3. Yang, Y., Tian, F., 2009. Abrupt change of runoff and its major driving factors in Haihe River Catchment, China. Journal of Hydrology. doi:10.1016/ j.jhydrol.2009.06.040. Yao, Q.N., 2003. Water resources and hydro-ecological environment of Haihe River Basin. Haihe Water Resources 6, 26e28. Zhang, G.H., Chen, S.E., Fei, Y.H., Nie, Z.L., 2003. Property of water resources shortage in Hai River basin and counter measure. Journal of Hydraulic Engineering 10, 113e118. Zhang, L.P., Xia, J., Lin, Z.H., Xiong, Z., 2008. Variation and transport feature of atmospheric water resources in Haihe River Basin. Journal of Hydraulic Engineering 39, 206e217. Zhang, Q., Xu, C.Y., Becker, S., Jiang, T., 2006. Sediment and runoff changes in the Yangtze River basin during past 50 years. Journal of Hydrology 331, 511e523. Zhao, C.L., Xiao, G.H., Luo, N.T., Yuan, Q.Y., Deng, P.C., 2007. The fish composition of Baiyangdian Wetlands. Hebei Fisheries 11, 49e50. Zheng, J.P., Chen, M.J., Xu, Z.X., Wang, F., Hua, Z.L., Cu, J.D., 2005. Calculation of minimum ecological flux of rivers for Haihe River Basin. Advances in Science and Technology of Water Resources 25, 12e15. Zhou, Y.M., Yu, X.B., Li, L.F., Zhang, C., 2007. New Concepts and Cases of River Management, WWF. Science Press, Beijing, China.
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Original article
Hydro-ecological impact of water conservancy projects in the Haihe River Basin Shanlong Lu a, Bingfang Wu a, *, Hao Wang a, Ninglei Ouyang a, Shuying Guo b a b
Institute of Remote Sensing Applications, CAS, No.1 Beichen West Road, 100101 Beijing, China Haihe River Water Resources Committee of China, 300170 Tianjin, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 January 2011 Accepted 13 July 2011 Available online 5 August 2011
Water conservancy projects are commonly constructed with different purposes. This usually results in improved flooding control, but may lead as well to environmental problems, such as river dry up, river morphology change, and reduction in biodiversity. The present study considers water conservancy projects in the Haihe river basin, following the major flood in 1963. It maps the water projects as well as the surface water bodies in 1964, 1980 and 2004, by using an integrated method of remote sensing and field surveys. The impact of the water conservancy projects on the hydro-ecological processes and the ecological environment is analyzed. Construction of the controlled reservoir resulted in a sharp drop of the river discharge and sediment. It also resulted in a reduction of river infiltration, an increase of evaporation and a change in regional water balance characteristics. Furthermore, the projects separated the hydraulic connection between upstream and downstream areas, weakened the river’s natural connectivity, and changed the dynamic conditions of the river water. On the basis of the study, we propose changing the operation mode of the existing controllable water conservancy projects and removing the projects with degraded and unreasonable functions as two optional ways to resolve the hydro-ecological problems of the basin. Ó 2011 Elsevier Masson SAS. All rights reserved.
Keywords: Runoff Sediment River infiltration Water surface evaporation Channel connectivity Flow continuity Biological diversity
1. Introduction The construction of water conservancy projects after major flooding can be guided by various purposes. We distinguish four categories, all leading to water management projects. When combined, these projects have as a common aim to protect human life and property, and to provide water and electricity, flood control and recreation services. The first purpose is to protect residential areas from the threat of floods and it requires establishment of levees, flood channels and flood catchments. The second purpose is to develop shipping facilities and industrial and agricultural production. It is mainly achieved by dredging activities and the construction of river channels. The third purpose is the intercept and transfer of available water. It can be achieved by the construction of reservoirs and water diversion projects. The fourth purpose is to meet the needs of leisure and entertainment, which leads to the construction of sluices and dams. Such projects, however, also lead to significant changes to the river ecological environment: river dikes cut off the relationship between river flood plains and river channels, and reduce wetland habitats, shipping and water recreational activities squeeze the space for
* Corresponding author. E-mail address: [email protected] (B. Wu). 1146-609X/$ e see front matter Ó 2011 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.actao.2011.07.003
aquatic organisms, river bank protection works reduce the area of aquatic habitats, and reservoirs and the water transfer projects change the spatial and temporal pattern of regional water resources. Among these, the environment that seriously damaged by dam construction and the dam-related activities (such as irrigated agriculture and water entertainment), resulting in a serious reduction in freshwater biodiversity. Currently, more than 60% of the world’s major rivers are subject to hydrological management. The wetlands were drained into agricultural land, and many fish stocks were plummeted (Zhou et al., 2007). In China, facing the increasingly serious environmental problems, the government has begun to improve upon the river management measures that have been used in previous years. Reflection on sustainable river management by making room for the river through protection and restoration of the natural river flow and of river hydrological processes, is gradually being accepted and practiced (Jiang et al., 2006; Rohdea et al., 2006). As a comparison, in the United States, nearly 500 dams have been removed to restore the natural fish populations and to reduce the harm to the local residents’ lives and property, caused by dams (Sparks et al., 2000). In order to prevent flood damage, improve watershed environmental quality, and to give more room for the river, the Netherlands proposed a series management measures called “Room for the river”, leading to broadening and deepening river channels, cleaning up the non-water conservancy facilities on
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the river bed and dredging the marshes and puddles at both sides of the rivers (Arnhem, 2006). Haihe River is one of the China’s seven major river systems. It has been subject to big changes during the last 2000 years. Changes to the two main subsidiaries, i.e. Weihe River, Zhanghe River, and the Hutuohe River in the south of the basin started as early as the Han Dynasty (1st century AD). Changes to the Yongdinghe River and the Jiyunhe River in the north of the basin, resulting in muddy rivers, started in the middle Min Dynasty (13th century AD) (Tan, 2002). To overcome the negative influence on the production and life caused by the river water regime in different stages, different management measures were taken. The Yongdinghe River, for example, experienced three significant changes on the management and development. During the Three Kingdoms period up to the Sui and Tang Dynasties, the river was mainly developed for irrigation and navigation, during Liao and Jin Dynasties to Min and Qing Dynasties the main management activities is dike construction, whereas during the years of the Republic of China, no maintenance was applied to the river due to the economic and social turmoil (Li, 2005). Since the founding of the People’s Republic of China, especially after the 1963 flood disaster in the Haihe River Basin, large-scale water conservancy projects have been constructed, in order to solve the long-term problems of flood disasters to the production and life of the basin, including reservoirs, man-made channels, ditches and dikes. Until 1980, a flood control and drainage system has been established, leading to a successful change in the frequent flooding. With the construction and implementation of the water conservancy projects, however, the basin environment has been degraded gradually (Haihe River Water Resources Committee, 2004). At present, the conflict of water supply and demand among socioeconomic development, production and living, and eco-system health is prominent. Development of water resources and utilization of the whole basin has increased above 120% (Zhang et al., 2008). The ecological environment is thus drying, following the reduction of the surface water, the continually groundwater level decline, and the increased surface and groundwater pollution (Yao, 2003). The objective of this study is to clarify the impact characteristics of the water conservancy projects construction on the hydrological regime and eco-environment, and to analyze the key processes of the eco-environment degradation. To do so, we use an integrated method of remote sensing and field surveys, and obtain the change information of the water conservancy projects and the surface water bodies in 1964, 1980 and 2004. This allows us to analyze the impact of the establishment of water conservancy projects on parameters of the hydro-ecological processes, such as river runoff and sedimentation, river infiltration capacity, water surface evaporation, river connectivity and biodiversity. The study proposes measures to adjust the function and spatial distribution pattern of the regional hydraulic projects. 2. Study area The Haihe River Basin is located in the Hebei Province in China, and contains the two major cities of Beijing and Tianjin; parts of Inner Mongolia autonomous region, and then Shanxi, Henan, Liaoning and Shandong Provinces. The catchment covers an area of 318,000 km2. The northwestern part of the basin has a higher elevation than the southeastern part. The basin receives its water in the west from the Shanxi Plateau and Taihang Mountains, and in the north from the Mongolia Plateau and the Yanshan Mountains. The area of the mountains accounts for 60% of the total basin area, whereas plains in the east and southeast account for 40% of the total basin area. The basin includes three river systems: the Haihe River, the Luanhe River, and the Tuhai-Majia River. Among these, the Haihe River is the major river system. It stretches between 111.96 and
118.48 E longitudes and between 35.00 and 41.61 N latitude (Fig. 1), and is composed of the Jiyunhe River, the Chaobaihe River, the Beiyunhe River, and the Yongdinghe River in the north of the basin, and the Daqinghe River, the Ziyahe River, the Zhangweihe River and the Heilongguangyundong River in the south of the basin, with an area of 234,600 km2. The study region belongs to the East Asian monsoon climate of the temperate zone with four distinct seasons. The annual average temperature is 1.5 e14 C, and the annual average relative humidity is 50%e70%. The average annual rainfall is 539 mm (calculated using the 1956e2000 rainfall series), concentrated mostly during the flood season from June to September (Editor Board of Haihe Records, 1997). The total population of the study area equals 109.55 million in 2007, accounting for 8.5% of the total population of China. Of these, 41.35 million (37.7%) live in cities. 3. Data and methodology In this study, the hydro-ecological impact analysis of the water conservancy projects construction has been divided into two parts. The first part is to assess the hydrological and ecological parameters in a quantitative way. This concerns information extraction of river runoff, sediment from hydrological yearbooks and extraction of hydraulic engineering numbers and river morphological changes from satellite remote sensing images and field surveys. The second part is to quantitatively characterize hydro-ecological processes. This will be based on the changes of surface water bodies (Tweed et al., 2009), river connectivity (Bednarek, 2001), and biodiversity. 3.1. Data sources The Haihe River Basin Hydrological Yearbooks (1954e2000) are used to obtain the river runoff and sediment data. The CORONA KH4A (resampled to a spatial resolution of 7.5 m) and CORONA KH-9 (resampled to a spatial resolution of 9 m) spy satellite images acquired in 1964 and 1980, and the SPOT 5 images (spatial resolution 2.5 m) in 2004 were used to map the hydraulic engineering. In addition, the KH-4A images of 1964, the Landsat MSS (57 m resolution) images of 1980, and the Landsat TM (30 m resolution) images of 2004 are used to map the changed surface water bodies. 3.2. Field survey The survey area covers the 5 sub-basins of the Chaobaihe River, Yongdinghe River, Daqinghe River, Ziyahe River, and ZhangWeihe River, including 28 rivers, 16 reservoirs, 7 flood catchments, 6 water control projects and 90 small-scale water conservancy projects. The purposes of field survey are establishing the satellite remote sensing image interpretation symbols and investigating the river channel morphological changes around the hydraulic engineering structures. Before the survey, some default field survey regions were based on the SPOT 5 satellite images. During the survey, the handheld GPS was used to obtain the precise position of each observation point. The relative positions between the observation points and the hydraulic engineering structures (their types, size, functions and conditions), the hydraulic contact between upstream and downstream of the project, the surrounding ecological environment, and land use were recorded. 3.3. Satellite remote sensing monitoring 3.3.1. Water conservancy project interpretation Referenced to the field survey photos and the SPOT 5 satellite images, the spatial distribution of the water conservancy projects
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Fig. 1. Location of the study area in northeast China.
including reservoirs, dams, and sluices in 2004 was mapped, using visual interpretation. Similarly, water conservancy projects constructed in 1964 and 1980 were mapped from the CORONA KH-4A and CORONA KH-9 spy satellite images. 3.3.2. Surface water body mapping The K-Means unsupervised classification method was used to map surface water body from the grey-scaled CORONA KH-4A images, whereas incorrectly mapped water body boundaries and polygons were manually modified. Fig. 2 presents the integrated water body mapping method combining the Normalized Difference Water Index (NDWI) (McFeeters, 1996) and the slope data to map water bodies from the 1980 Landsat MSS images. The NDWI was used to extract the initial water body boundaries, and the slope data generated from the digital DEM were used to eliminate the influence of the mountain
Fig. 2. Water body mapping method for Landsat MSS images.
shade (Lu, 2008). During mapping, the histogram of each NDWI images was used to obtain the threshold (T1) between water bodies and other features. Thresholds for the NDWI images of the study area range from 0.1 to 0.5. Similarly, a slope threshold of 10 was used to eliminate the influence of the mountain shade (Lu, 2008). Then the final accurately distributed water bodies were mapped. For water body mapping with Landsat TM images, we combined the Modified Normalized Difference Water Index (MNDWI) (Xu, 2005), the Tasseled Cap Wetness Index (TCW) (Huang et al., 2002), and slope data (Fig. 3). The MNDWI extracts the initial water body boundaries, the TCW enhances the accuracy of the shallow water wetland boundary extraction (Ouma and Tateishi, 2006; Ordoyne and Friedl, 2008), and the slope data eliminates
Fig. 3. Water body mapping method for Landsat TM images.
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the influence of the mountain shade (Lu, 2008). The histogram of each MNDWI images provided the threshold (T3) between water bodies and other features. Thresholds for all MNDWI images within the study area range from 0.2 to 0.2. A TCW threshold equal to 0 was used to distinguish the boundaries between water and sediment mixing zone as the values of the water bodies are less than 0 in the TCW images. Finally, a slope threshold of 10 was used to eliminate the influence of the mountain shade (Lu et al., 2011).
being mainly constructed before 1964. The medium-sized reservoirs increased evenly, with 39 reservoirs constructed before 1964, 38 during the period of 1964e1980, and 30 between 1980 and 2004. The number of small reservoirs also increased. There are 399, 406, and 349 small reservoirs built in the three period of time, respectively. River dams, rubber dams, and sluices, were mainly constructed after 1980 (Table 1). 4.2. The hydro-ecological impact of the water conservancy projects
3.4. Hydro-ecological impact characterization The parameters of river infiltration, surface water evaporation, river connectivity and flow continuity were used to quantitatively characterize the hydro-ecological impact from the water conservancy projects of the study area. River infiltration plays an important role on maintaining the river ecological water balance. The infiltration changes caused by river water changes were calculated with the following formula:
Ds ¼
ðst s0 Þ t
(1)
DV ¼
1 t ðt þ 1Þ D s 365 s 2
(2)
where Ds is the change of the average annual river water area (km2), st and s0 are the river water area at the starting and ending time (km2), DV is the total changed volume of the river infiltration (m3), s is the permeability coefficient (m yr1), and t is the calculation time period. The changed surface water will influence the evaporation of the basin, and have an impact on the regional water resources (Tian et al., 2005). The evaporation water losses caused by surface water changes can be calculated by the formula (3):
1 2
D E ¼ E t s0 ðt þ 1Þ D s
(3)
where DE is the total evaporation water loss in the study period (m3) and E is the average annual pan evaporation (m). The conversion factor between the pan evaporation and actual evaporation equals 0.7 0.2 (Tweed et al., 2009). River connectivity (Rcon) is a key indicator to reflect the river habitat conditions. It equals the ratio of the total quantities (Dn) of the reservoirs, rubber dam, and sluices and the total length of the river (Rl). The formula is as follows:
Rcon ¼ Dn =Rl
(4)
A large Rcon value corresponds with a low channel connectivity. Flow continuity (Fcon) is the basis for the river hydrological continuity, nutrient delivery, and biological community continuity. It is calculated as the ratio of the river channel with water (Wl) and the total length of the river (Rl):
Fcon ¼ Wl =Rl
4.2.1. Changed river runoff Between 1964 and 2004, the average annual pan evaporation and precipitation of Haihe River Basin was equal to 1100 mm and 539 mm, respectively. As evaporation exceeds by far the precipitation, the construction of the water conservancy projects will reduce the river runoff. Monitoring of the runoff data from the Water Conservation Centre of Haihe River Water Resources Committee shows that the average annual runoff to the Suzhuang gauging Station reduced from 2.93 109 m3 to 0.95 109 m3, after construction of the Miyun Reservoir in 1960 (Fig. 4). The river runoff in other sub-basins also changed with the construction of the upstream water conservancy projects. In Fig. 5, the separation point of the precipitation and runoff downward curves indicates the starting point of an abrupt runoff change in each sub-basin. Such a significant changing time of the average annual runoff coincides with the time for the water conservancy project construction. For the Yongdinghe River Basin, changes in runoff are related with construction of the Guanting Reservoir between 1951 and 1954. The northern and southern Daqinghe River Basin is mainly controlled by the Wangkuai Reservoir and Xidayang Reservoir, built between 1958 and 1960. The Hutuohe River Basin is mainly impacted by the construction of the Huangbizhuang Reservoir and Gangnan Reservoir between 1958 and 1960. And the Fuyanghe River Basin is mainly controlled by the construction of the Dongwushi Reservoir between 1958 and 1959 (Table 2).
(5)
A large Fcon values indicates a high flow continuity. 4. Results 4.1. The changes of the water conservancy projects construction Interpretation of the satellite remote sensing images of 1964, 1980, and 2004 shows that the number of water conservancy projects dramatically increased during the last 40 years. The reservoirs number increased from 462 to 1287, the large reservoirs
4.2.2. Reduced sediment transfer The construction of the large number of water conservancy projects resulted in substantial blocking of sediment. At the end of 2000, most small reservoirs upstream of the Guanting Reservoir have already overwhelmed. The total deposit volume is 147 106 m3, whereas the total deposit volume for the large and the medium-sized reservoirs equals 441 106 m3 (Liu and Hu, 2004). For the Miyun Reservoir, for example, the average annual sediment transferred to the Suzhuang gauging station reduced from 907.8 tons to 40.7 tons, accounting for a 95.5% reduction, immediately after building the reservoir in 1960 (Fig. 4). 4.2.3. Decreased river infiltration volume From previous studies (Fan et al., 2008; Hu et al., 2009) we know that the average permeability coefficient of the Haihe river bed ranges between 0.0347 and 0.21 m day1. The changed infiltration volume caused by the changed river water area in different periods is calculated using equations (1) and (2) and taking the minimum average permeability coefficient of 0.0347 m day1 and the three Table 1 Water conservancy projects constructed in 1964, 1980, and 2004. Year
Water conservancy projects (Quantities) Reservoir
1964 1980 2004
Dam
Large
Medium
Small
River dam
Rubber dam
24 26 26
39 77 107
399 805 1154
11 12 346
0 0 59
Sluice
Total
33 69 481
506 989 2173
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Fig. 4. The runoff and sediment data measured on the Suzhuang gauging station downstream of the Miyun Reservoir (The data is provided by the Water Conservation Centre of Haihe River Water Resources Committee).
phases from Table 3 as the basic data. For the period from 1964 to 1980, the total volume of the infiltration reduction caused by the reduced river water area is 73.09 109 m3 and the average annual decrease is 4.57 109 m3. From 1980 to 2004, the total volume of the infiltration reduction is 140.44 109 m3, with an average annual decrease of 5.85 109 m3. 4.2.4. Increased reservoir surface water evaporation water loss The total evaporation water loss of the reservoir surface water was calculated with the formula (3), using the 1952e2001 time series pan evaporation data and taking the three phases from
Table 3 as the basic data. The results show that from 1964 to 1980, the total reservoir evaporation water loss is between 12.86 109 m3 and 23.15 109 m3 and the average annual evaporation water loss is between 0.8 109 m3 and 1.45 109 m3. Between 1980 and 2004, the total evaporation water loss is between 15.33 109 m3 and 27.6 109 m3, with an average annual evaporation water loss between 0.64 109 m3 and 1.15 109 m3. 4.2.5. Changed river connectivity and flow continuity From 1964 to 2004, the connectivity of the Yongdinghe River, Chaobaihe River, Daqinghe River, Ziyahe River, and Zhangweihe
Fig. 5. Changes in the average annual precipitation and runoff of the Yongdinghe River Basin, the north of the Daqinghe River Basin, the south of the Daqinghe River Basin, Hutuohe River Basin, and Fuyanghe River Basin obtained by using the Mann-Kendall method (Liu et al., 2004). The thick solid line represents the precipitation, whereas the thin solid line represents the runoff. The vertical axis represents the sequential values of the statistic U(t) calculated with the Mann-Kendall method.
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5. Discussion
Table 2 Construction periods for several large reservoirs in Haihe River Basin. Basin
Reservoir
Construction period
Yongdinghe River Basin The north of the Daqinghe River Basin The south of the Daqinghe River Basin Hutuohe River Basin
Guanting Reservoir Xidayang Reservoir
1951e1954 1958e1960
Wangkuai Reservoir
1958e1960
Huangbizhuang Reservoir Gangnan Reservoir Dongwushi Reservoir
1958e1959
Fuyanghe River Basin
1958e1959
Table 3 River and reservoir surface water area in different time period (km2). Period
1964
1980
2004
River surface water area Reservoir surface water area
1928.1 1582.9
1249.2 1348.8
362.1 985.0
River decreases gradually. Before 1980, the Zhangweihe River has a higher connectivity than the Chaobaihe River and the Ziyahe River, whereas the Daqinghe River has a higher connectivity than the Yongdinghe River. At the end of 2004, the river with the lowest connectivity is the Chaobaihe River, followed by the Yongdinghe River, the Daqinghe River, the Zhangweihe River and the Ziyahe River. In the same period, the flow continuity of the Yongdinghe River, the Daqinghe River, and the Ziyahe River continuously decreases. The Chaobaihe River experienced a gradual recovery after years of connectivity decrease, whereas such a decrease occurred for the Zhangweihe River after 1980 (Table 4). 4.2.6. Reduced biodiversity Restrictions by available data, fish species in the wetlands are chosen as an indicator to reflect the biodiversity changes. Since 1960s, the fish species in the wetland are greatly decreased. Before the 1960s, the Qilihai wetland as a natural spawning field for the anadromous fish contained more than 30 fish species. After the mid 1970s, these fish species have become extinct (Wang et al., 2005). Similar conditions occurred to the Baiyangdian wetland, another wetland area in the Haihe River Basin, also called the Pearl of the North China Plain. From 1958 to 1998, the number of fish species in the Baiyangdian wetland sharply declined. Thereafter, the number slowly increased (Fig. 6).
In the past, the managers and scientists have had a widespread concern on hydro-ecological impacts caused by the construction of the water conservancy projects (Xu, 2004; Wang et al., 2005; Zhao et al., 2007; Yang and Tian, 2009). Usually, the river runoff and sediment deposition have been taken as the key indicators for analyzing the environmental changes and the impact of the human activities (Zhang et al., 2006; Fiener and Auerswald, 2006; Wang et al., 2008). Regional water resources distribution, however, as well as the hydrologic connectivity and continuity are rarely considered, because of scarcity of the data. With the help of satellite remote sensing images, this paper quantified the two important types of hydro-ecological parameters. Although, the infiltration in the agricultural land that irrigated by river water was not considered in the river infiltration and surface water evaporation calculation, and the impact of the acquisition time difference of the remote sensing images on surface water mapping was not considered in the river connectivity and flow continuity characterization, these quantitative data provide new way for river hydroecological process research. The main purpose of the Haihe River water conservancy projects construction has been flood controlling and irrigation (Wu and Lu, 2011). Potential floods can now be blocked and water resources can be stored, thus forming a basis for the water conservancy projects. During the past 40 years, however, there have been no large-scale floods, except for the storm floods in the south of the Haihe River Basin in 1996 (Yang et al., 2005). Therefore, many of the water conservancy projects have long been operated with a low or even negative efficiency. They have had a serious impact on the efficiency of using water resources for animal life, production and ecological requirements. The reservoirs constructed in the upstream stopped the fish moves down the river, and the construction of dam in the downstream cut off the anadromous migration channels for fishes. Which make many fish species came to extinct. For example, the water interception and water transfer from the upstream reservoirs of Baiyangdian wetland caused large changes in fish species diversity and in their quantities (Zhao et al., 2007). And the tide keeping sluice, constructed at the end of the 1960s and the early 1970s, resulted in a yearly decrease of anadromous fish species in Qilihai wetland (Wang et al., 2005). Furthermore, the decreased water yield and increased water pollution caused by climate
Table 4 Parameters of the river connectivity and the flow continuity in sub-basins of the Haihe River Basin.a Year
Sub-basin
River length (km)
Water conservancy projects (number)
River length with water (km)
River connectivity (number/km)
Flow continuity
1964
Yongdinghe River Chaobaihe River Daqinghe River Ziyahe River Zhangweihe River Yongdinghe River Chaobaihe River Daqinghe River Ziyahe River Zhangweihe River Yongdinghe River Chaobaihe River Daqinghe River Ziyahe River Zhangweihe River
920 777 474 1166 1337 920 777 474 1443b 1337 920 777 474 1443b 1337
16 8 5 12 5 43 19 18 22 10 104 105 50 74 84
751.9 685.2 448.4 1164.1 1082.5 619.2 557.7 419.3 1206.6 1148.9 610.4 616.5 230.0 947.7 449.0
0.017 0.010 0.011 0.010 0.004 0.047 0.024 0.038 0.015 0.007 0.113 0.135 0.105 0.051 0.063
0.818 0.882 0.946 0.998 0.810 0.673 0.718 0.884 0.836 0.860 0.664 0.794 0.485 0.657 0.336
1980
2004
a The rivers in each sub-basins: Yongdinghe River Basin (Yongdinghe River, Yongdingxinhe River, Yanghe River, Sangganhe River, Guishuihe River), Chaobaihe River Basin(Chaobaihe River, Chaohe River, Baihe River, Chaobaixinhe River), Daqinghe River Basin(Daqinghe River, Duliujianhe River, Haihe River, Baigouhe River, Zhongtinghe River, Zhaowangxinhe River, Caohe River), Zhangweihe River Basin(Zhangweixinhe River, Weiyunhe River, Zhanghe River, Zhuozhanghe River, Qingzhanghe River, Weihe River, Nanyunhe River), Ziyahe River Basin(Hutuohe River, Fuyanghe River, Ziyahe River, Fuyangxinhe River, Ziyaxinhe River). b It includes the length of the two canals namely Fuyangxinhe River and Ziyaxinhe River that were excavated between 1965 and 1967.
S. Lu et al. / Acta Oecologica 44 (2012) 67e74
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Fig. 6. The number of fish species in the Baiyangdian Wetland from 1958 until 2007 (Zhao et al., 2007).
change, land and tourism development also increased the reduction of the fish resources (Cao et al., 2003). From 1964 to 2004, the reservoir surface area of the basin gradually reduced, with a total reduction equal to 597.9 km2 (37.8%) (Table 3). Many of the dried up reservoirs in the basin have lost their original function (Fig. 7) as they not only did not play the role of water reserving, but also blocked runoff formation from precipitation, increased the evaporation water loss, and consequently have an impact on rainfall supplies to the downstream rivers. The estimation results in sub-sections 4.2.3 and 4.2.4 show that the basin water resources loss due to the reservoir water reserving and reduction of the river runoff reaches to 52.1 109 to 73 109 m3 per year. This value is equivalent to 56%e78% of the water requirement that should be transferred from outside of the basin (Zhang et al., 2003). In addition, small hydraulic engineering constructions such as river dam, rubber dam and sluices to meet water demand for the local agricultural production, daily life and recreation (Fig. 8, September 15th, 2008), exacerbated the regional hydro-ecological environment degradation. They cut off the river flow into different parts, thus increasing the evaporation and blocking migration routes of fish (Wang et al., 2005). Therefore, for water conservancy projects with degraded or unreasonable functions, changes in the operation mode (Zheng et al., 2005) or removing the projects (Graf, 2002) could be reasonable choices. This may alter negative impacts on river water dynamic conditions and water resources distribution. To return to the original conditions of the natural river flow, existing
Fig. 8. The concrete river dam (top) and rubber dam (bottom) in the Chaobaihe River Basin.
controllable engineering facilities could be used. This could lead to a new operation mode of storing water in flooding time, releasing it in the dry season. This may help to restore the river flow dynamics, and ensure a minimum instream ecological flow (Liu et al., 2010). In this sense, the function of the existing water conservancy projects should be evaluated, both from the point of view of engineering operation efficiency and from a sustainability point of view. Projects with degraded and unreasonable functions, such as abandoned reservoirs and small flow engineering blocks, should then be removed. In this way, the longitudinal river connectivity, and the vertical and lateral water exchange in the river channel can be restored. Engineering practices and researches in last decade already indicate that dam removal is an effective river restoration method (Bednarek, 2001; Schmitz et al., 2009). In the study period, the changing patterns of river connectivity and flow continuity are different in different sub-basins. Different
Fig. 7. Change detection of the Baohe Reservoir in the Daqinghe River Basin.
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S. Lu et al. / Acta Oecologica 44 (2012) 67e74
control measures should have been installed to protect or restore the river hydro-ecological environment. For the Yongdinghe River Basin, the Daqinghe River Basin, and the Ziyahe River Basin, restoration of the flow continuity by changing the operation mode of the existing water conservancy projects could be good choices at present. For the Chaobaihe River Basin, under the premise of maintaining the growth trends of the flow continuity, removal of some small hydraulic engineering constructions (Fig. 8) may be an attractive way to restore aquatic biodiversity. Because there are some reservoirs including another large reservoir will be built upstream of the Zhangweihe River Basin (Department of Hebei Water Resources, 2007) in the near future, for the Zhangweihe River Basin, stopping or reducing the planned water conservancy projects construction is most likely the best option. 6. Conclusions The construction of the water conservancy projects greatly changed the hydrological characteristics of the Haihe River. During the period of 1951e1960, influenced by the controllable reservoir construction in each sub-basin, the discharge and sediment flow downstream to all the rivers sharply declined. The changed water surface area of the rivers and reservoirs resulted in the reduction of the river infiltration and increasing of the water surface evaporation. This, in turn, changed the regional water balance of the basin. In addition, water conservancy projects blocked the hydraulic connection between upstream and downstream, and destroyed the river’s natural connectivity. Which resulted in the decreasing of the fish species. On the basis of this study, we propose of changing the operation mode of the existing projects and removing the projects with degraded and unreasonable functions as the two optional ways to solve the current hydro-ecological environmental problems in the basin. Acknowledgments We would like to acknowledge the financial support of the Key Innovation Project of the Chinese Academy of Sciences (KZCX1-YW08-03, KSCX1-YW-09-01). Thanks to the Haihe River Water Resources Committee of China for providing the archived SPOT 5 images. We also thank the National Data Sharing Network of Earth System Science (www.geodata.cn) and the U.S. Geological Survey Data Sharing Network (http://glovis.usgs.gov) for providing the Landsat MSS/TM/ETMþ images. References Arnhem, M.A.W., 2006. Spatial Planning Key Decision ‘Room for the River’. http:// www.ruimtevoorderivier.nl (12.01.09). Bednarek, A.T., 2001. Undamming rivers: a review of the ecological impacts of dam removal. Environmental Management 27, 803e814. Cao, Y.P., Wang, W., Zhang, Y.B., 2003. Present situation of fish stocks in Baiyangdian Lake. Chinese Journal of Zoology 38, 65e68. Department of Hebei Water Resources, 2007. Flood Control Planning in Hebei Province. http://www.cjw.com.cn/index/detail/20071219/98310.asp. Editor Board of Haihe Records, 1997. Haihe Records, vol. I. China Water Power Press, Beijing, China. Fan, X.M., Liu, G.H., Shu, L.C., Liu, Q.S., 2008. Field measuring the hydraulic conductivity of different sediments in Yellow River Delta. Journal of Water Resources & Water Engineering 19, 6e10. Fiener, P., Auerswald, K., 2006. Seasonal variation of grassed waterway effectiveness in reducing runoff and sediment delivery from agricultural watersheds in temperate Europe. Soil & Tillage Research 87, 48e58. Graf, W.L., 2002. Dam removal research status and prospects. In: Proceedings of The Heinz Center’s Dam Removal Research Workshop October 23e24, 2002. The H. John Heinz III Center for Science, Economics and the Environment. http://www. heinzctr.org. Haihe River Water Resources Committee, 2004. Water Resources Protection Plan for the Ecological Environment Restoration of Hai Basin.
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