Basic situation of Henan water receiving area in the middle route of South-to-North Water Transfer Project

In this study, the first phase of the middle route of South-to-North Water Transfer Project in Henan Province is selected as the research object. This area belongs to the semi-humid monsoon climate zone, influenced by atmospheric circulation, with the characteristics of drought and windy in spring, hot and rainy in summer, sunny and cool in autumn and cold and dry in winter. See Figure 4. 1 for the location of Henan water receiving area in the first phase of the Middle Route of South-to-North Water Transfer Project.

Fig. 4. 1 Schematic diagram of the location of water receiving area in the first phase of the Middle Route of South-to-North Water Transfer Project

Fig. 4. 1 Middle Route of South-to-North Water Transfer Project 1 Location of Project Water Receiving Area

4. 1. 1 water receiving area

According to the General Report on Feasibility Study of the First Phase of the Middle Route of South-to-North Water Transfer Project, the first phase of the Middle Route of South-to-North Water Transfer Project takes water from the first sluice of Taocha Canal in Danjiangkou Reservoir of Hanjiang River, crosses Fangchengyakou, a watershed in the Yangtze River Basin and Huaihe River Basin, excavates channels along the western edge of Huanghuaihai Plain, crosses the Yellow River through tunnels or aqueducts in Gubaizui, west of Zhengzhou, and goes north along the west side of Beijing-Guangzhou Railway, which can basically flow to Beijing and Tianjin by itself. The water supply targets of the first phase of the Middle Route of South-to-North Water Transfer Project are mainly Beijing, Tianjin, Shijiazhuang, Zhengzhou and other towns. Because the location of the main canal of the middle route project is higher than the whole water receiving area, emergency water supply can be implemented when extreme drought occurs in some parts of North China.

There are 1 1 provincial cities and 32 counties (including 7 county-level cities) in Henan's water receiving area of the Middle Route of South-to-North Water Transfer Project. See Table 4. 1 for the water receiving area. 1 1 Among the provincial cities, there are 6 in the south of the Yellow River (Nanyang, Pingdingshan, Luohe, Zhoukou, Xuchang and Zhengzhou), 5 in the north of the Yellow River (Xinxiang, Jiaozuo, Hebi, Anyang and Puyang), 0/8 in the south of the Yellow River and 0/4 in the north of the Yellow River.

Table 4. 1 Water Receiving Area of Henan Province in the First Phase of the Middle Route of South-to-North Water Transfer Project

4. 1.2 Physical geography of water receiving area

The Middle Route of South-to-North Water Diversion Project is distributed in a strip shape along the main canal of Henan Province, and the Henan section of the Middle Route Project is 73 1km. Nanyang basin in the south belongs to the Hanshui River basin of the Yangtze River. It is surrounded by Tongbai Mountain and Funiu Mountain in the west, north and east, and adjoins Jianghan Plain in the south. The basin edge is hilly and undulating. The terrain in the basin is gentle, with the ground elevation of 80 ~ 150m and the ground slope of 1/500 ~ 1/65438+. North of Fangcheng and south of the Yellow River, it belongs to Huaihe River Basin, piedmont hilly area and Huaibei Plain area. The surface inclines to the southeast, with an elevation of 45 ~ 150m and a ground slope of1/3000 ~110000. The north of the Yellow River belongs to the alluvial plain in front of Taihang Mountain in the Yellow River and Haihe River basins. The terrain inclines from southwest to northeast, with an altitude of 50 ~ 1 100 m, and the ground ratio drops to 1/3000 ~ 1/4000. Most of the water receiving areas are flat and open, and the ground slopes from west to east, so they can deliver water by themselves. Part of the water receiving area is located in the hilly area west of the main canal, with an altitude of150 ~170 m.

There are more than 400 large and small rivers crossing the central main canal in the receiving area, and the three rivers in the south, middle and north flow in the south, southeast and northeast directions, which are orthogonal to the main water diversion canal. The main rivers with basin area greater than 100km2 are: Diaohe River, Turbulent River, Baihe River and Zhaoqian River in Tangbai River Basin; There are Shahe, Beiruhe, Heying and Jia Luhe in the Huaihe River Basin. The Yellow River and Haihe River basins include Qinhe River, Dasha River, Tanghe River and Anyang River.

The water receiving area is located in the transition zone from subtropical zone to warm temperate zone, which belongs to continental monsoon climate. The average rainfall for many years is 900 ~ 550 mm, which decreases from west to north, including 900 ~ 800 mm in Tanghe River Basin, 850 ~ 650 mm in Huaihe River Basin and 600 ~ 550 mm in Haihe River Basin. The precipitation varies greatly from year to year and is unevenly distributed during the year. The difference between the maximum and minimum rainfall in wet and dry years is 2 ~ 3 times, and the rainfall in flood season from June to September accounts for 60% ~ 75% of the whole year. The annual average temperature in the water receiving area is 13 ~ 15℃, and the frost-free period is 190 ~ 230 days. The plain area has good soil quality and is suitable for the growth of various crops. It is a major agricultural producing area.

The average annual precipitation in the receiving area is 72 1.8mm, showing a trend of more in the south and less in the north. According to Annex 4 Urban Water Resources Planning of South-to-North Water Transfer Project, the surface water resources in this area are 128.9× 108 m3, the non-repetitive groundwater resources are 57.3× 108 m3, and the total water resources are 186.2× 108 m3. The temporal and spatial heterogeneity of surface runoff is significant, and the runoff is the largest from June to September, accounting for 90% of the whole year. Due to the serious over-exploitation of groundwater, the groundwater level continues to decline, the recharge is decreasing year by year, and the groundwater resources are decreasing day by day.

4. 1.3 Socio-economic status of the water receiving area

The first phase of the Middle Route of South-to-North Water Transfer Project is located in the North China Plain, with abundant natural resources and superior geographical location. It is the political, economic and cultural center of China. The water-receiving area is densely populated, with a high level of overall economic development and good industrial and agricultural production infrastructure. It is an important industrial base, an important grain, cotton and oil producing area and a key economic zone in China. The counties (cities) involved in this water-receiving area have a very important strategic position in China's economic and social development and food security. Pingdingshan, Jiaozuo, Hebi and Puyang are the main production bases of coal, electric power and petrochemical industries. The textile, metallurgy, building materials, electronics and household appliances industries in Zhengzhou, Xinxiang and Anyang have developed rapidly, while those in Nanyang, Luohe, Xuchang and Zhoukou are mainly textile, metallurgy, machinery, food, medicine and industry. The economic construction of these cities has an important leading position in the national social and economic development.

The study area is densely populated, with many large and medium-sized cities, developed economy and rapid development. According to statistics, the administrative division area of 1999 water receiving area is 5805km2, of which the built-up area is 839km2. The population of urban built-up area is 8.28 million, and the water consumption population is 9.55 million. The city's gross national product 108 1 100 million yuan, the output value of secondary and tertiary industries 59%, 4 1%, and the per capita GDP 13045 yuan; The total industrial output value135.2 billion yuan, including general industry128.8 billion yuan and electric power industry 6.3 billion yuan, accounting for 95.3% and 4.7% of the total industrial output value respectively. In 2005, the total population of the water receiving area was 59.29 million, and the gross domestic product was 743.3 billion yuan. The cultivated land area is 62.85 million mu, the grain output is 2889× 104 t, and the per capita GDP of the water receiving area is 654.38+0.25 million yuan/person, which is lower than the national average of 654.38+0.39 million yuan/person.

4. 1.4 water resources in the receiving area

The surface water in Henan Province varies greatly from year to year, and the runoff decreases from south to north. 70% of runoff is concentrated in the flood season, often concentrated in several rainstorms. Most rivers in the northern plain are basically cut off in non-flood season and become seasonal rivers. Most cities, counties and towns within the planning scope of the water receiving area along the line lack surface water source projects. Except for a few cities, large and medium-sized reservoirs and yellow river diversion channels in the west can take water and supply water, and the water supply mainly depends on the exploitation of groundwater. Urban groundwater exploitation is serious, and there is a middle-deep groundwater funnel area centered on urban water source. Industry and cities occupy more and more agricultural water, and the underground water source of urban water plants continues to expand to the suburbs of cities. The water conservancy project originally planned for agricultural water supply turned to urban water supply, which aggravated the contradiction between water supply and water use between regions and between industry and agriculture, and the shortage of water resources became the main factor affecting and restricting Henan's economic development.

There are more than 400 rivers crossing the central main canal in the receiving area, and the per capita water resources are less than the national average 1/8. Urban status: 1999, groundwater exploitation 12.56× 108 m3, of which deep groundwater is 5.36× 108 m3, 1997 ~ 1999. According to the three-year average statistics, the city overexploits groundwater by 7.93× 65438 every year. In the case of water shortage, there is no clean water source to maintain the water environment of rivers, most rivers dry up in non-flood season, and a small amount of runoff comes from sewage discharged by cities, which deteriorates the water quality.

The main characteristics of water resources in Henan receiving area of the first phase of the Middle Route of South-to-North Water Transfer Project are that the total amount of water resources is small, the spatial and temporal distribution is uneven, and continuous dry years often occur. In recent years, due to the combined influence of climate drought and human activities, the amount of water resources has obviously decreased. This change of water resources is an important reason for the serious water shortage in the receiving area. There are the following outstanding problems in the utilization of water resources: ① The water resources in the receiving area are short, and the contradiction between supply and demand of urban water resources is becoming increasingly prominent, which is the main problem in the development and utilization of water resources. The water supply of surface water source project is limited, and the present situation of water supply from large reservoirs to cities has reached or exceeded the planned water supply to cities; The water supply project of diverting water from the river is poorly guaranteed, and the water quality of the river does not meet the drinking water standard; The water supply of the Yellow River in the city is not guaranteed. (3) Overexploitation of groundwater in the water receiving area along the main canal of the Middle Route Project generally leads to a series of environmental geological problems. (4) Urban rivers are mostly sewage channels, and the water pollution is serious. ⑤ Insufficient water-saving investment and low water-saving efficiency.

4. 1.5 Eco-environmental conditions of water receiving area

Henan Province is located in the Central Plains, with an area of 16.7× 104 km2, accounting for 1.74% of the total land area in China, belonging to the Yangtze River, Huaihe River, Yellow River and Haihe River. Henan province is a typical province with a large population, agriculture, economy and culture, which plays an important strategic role in national and regional economic and social development. Henan is rich in resources, and the per capita water resources are only 1/5 of the national average. The contradiction between water resources carrying capacity and economic and social development and ecological environment is increasingly prominent. As the main water source and water receiving area of the middle route project, Henan Province will not only make important contributions to the construction and operation of the project, but also share the huge economic, social and environmental benefits brought by the project.

The water-receiving areas in Henan are mostly mineral resources-rich areas and industrial agglomeration areas, and the shortage of water resources makes it impossible to transform resource advantages into economic advantages. The implementation of the mid-line project will promote the transformation of local resource advantages into economic advantages through industrialization and promote the optimization and adjustment of industrial structure. Adequate water supply is helpful to break the shackles of small-scale peasant economy, develop modern agriculture and food processing industry, and accelerate agricultural industrialization and rural modernization; It is conducive to the optimization and adjustment of industrial layout and industrial structure, improving industrial productivity and promoting the development of new processing industries and modern high-tech industries.

The implementation of the mid-line project will promote the expansion of the city scale and the improvement of urbanization level in the water-receiving area. It is predicted that the urban population of Henan's water-receiving areas 1 1 provincial cities will increase from 1065438+ million at the end of 2004 to10/2.2 million in 20 10/765440 in 2020. The main canal runs through the densely populated urban areas of Henan Province, which will affect the urban form and functional structure of these towns. The improvement of water supply reliability will be conducive to the optimization of regional urban and rural land structure and spatial layout, promote the improvement of urban system, and provide permanent power for the healthy development of urbanization in Henan. Cross-administrative projects will promote the coordinated development between regions, which is manifested in frequent economic exchanges and policy coordination along the line. Reliable water supply system will promote the development of local secondary and tertiary industries and the extension of industrial chain, help upgrade industrial structure and urban functions, and strengthen the agglomeration and radiation of cities. The water receiving area of the mid-line project covers most areas of the Central Plains urban agglomeration. Under the interaction of regional coordination and urban development and expansion, it will produce driving factors that are conducive to the development of urban agglomerations, accelerate the development of urban agglomerations in the Central Plains with Zhengzhou as the center, lead the rise of the Central Plains and promote the rise of central China.

Water shortage in this area belongs to resource water shortage, and a series of economic, social and ecological environmental problems caused by excessive utilization of water resources cannot be solved by saving water and reusing sewage. The continuous decrease of water resources and the continuous deterioration of ecological environment will cause irreparable serious consequences. Therefore, it is necessary to implement the inter-basin water transfer and the middle route project of South-to-North Water Transfer to supplement the water supply in North China Plain. Only through the rational allocation of water resources between north and south can the contradiction between supply and demand of water resources in North China Plain be alleviated and the sustainable development of national economy and society in this area be supported. According to the principle of "saving water first, draining water first and using water first" in the South-to-North Water Transfer Project, all localities will pay more attention to ecological environment protection and water pollution control. The introduction of water resources and the adjustment and upgrading of industrial structure will be beneficial to the optimal allocation and rational utilization of water resources in economic activities, and the utilization efficiency of water resources will be improved through the combination of water saving, water pollution control and reclaimed water reuse. With the alleviation of water supply contradiction, ecological water can be guaranteed, which will effectively improve the wetland function of regional water system and the urban and rural ecological environment.

In addition to the above beneficial effects, the middle route project of South-to-North Water Transfer Project will inevitably have some negative effects on the ecological environment of Henan water receiving area. The construction of Danjiangkou Reservoir has flooded 362km2 of land in Xichuan County, including more than half of the county's cultivated land and a population of 220,000. The migrants' life has not been properly settled, which has caused the problem of returning home. After heightening the reservoir dam, 70km2 of flooded land was added, and 654.38+05,000 immigrants were added. A large number of land inundation and population migration in a short period of time will further aggravate the contradiction between man and land and the pressure of resources and environmental capacity. Long-distance water transfer across four major water systems in the Middle Route Project. Large-scale engineering construction will cause drastic changes in the local environment in a short time, change the topography and climate environment in some areas to a certain extent, reduce some land and forest resources, affect the original water system and vegetation ecology, and may also cause soil erosion and the destruction of wetland structure. And this adverse impact on the ecosystem is irreversible in the short term.

At the same time, the crossing area of the Middle Route Project is a region with profound historical and cultural heritage in China and an important birthplace of ancient civilization in China, with many cultural relics and a long span. Engineering construction is bound to bring great influence to the protection of cultural relics. On the one hand, engineering construction will inevitably cause damage to areas with dense cultural relics, especially underground cultural relics; On the other hand, the flooding of a large amount of land by reservoirs will lead to the flooding of cultural relics on the ground, which will increase the difficulty of cultural relics protection and bring losses to cultural tourism.

The main eco-environmental problems in this study area are as follows: First, the surface water dries up. The water consumption in the upper reaches and surrounding areas of the first-phase project of the Middle Route of Henan Province has increased rapidly, and the continuous drought in the north has significantly reduced the annual precipitation, resulting in the drying up of rivers, the extreme shrinkage of wetlands and water areas, and the obvious reduction of surface water. Second, groundwater overexploitation is serious. The surface runoff in the receiving area is reduced, and the degree of water resources protection is low. Overexploitation of groundwater has become a serious environmental problem in the receiving area. For example, the shallow groundwater level along the main canal of the first phase of the South-to-North Water Transfer Project in Henan Province is decreasing year by year, and the exploitation of the middle and deep groundwater in the city is increasing year by year. Due to the over-exploitation of urban groundwater, many environmental geological and engineering geological problems have arisen, resulting in land subsidence, groundwater funnel, ground cracks and other problems. Third, the degree of water pollution has intensified. In recent years, with the rapid development of social economy, urban water consumption and sewage discharge have also increased accordingly. A large amount of untreated wastewater is discharged into rivers, seepage wells and pits, and excessive use of pesticides and fertilizers has seriously polluted rivers, lakes and groundwater. Urban drinking water sources are also threatened by pollution, and nearly half of shallow groundwater in plain areas is polluted. Although all cities in the water receiving area of the first phase of the Central Line Project have strengthened urban sewage treatment and strictly controlled sewage discharge, the water environment pressure is still very high. Water pollution has aggravated the already serious water shortage.