Results of Eco-hydrological Regionalization of Henan Water Receiving Area in the Middle Route of South-to-North Water Transfer Project

Combined with the actual situation, the cluster analysis results are further adjusted, merged and named, and the eco-hydrological regionalization results of Henan water receiving area in the first phase of South-to-North Water Transfer Project are obtained.

4.3. 1 Naming standard

According to the results of SP SS cluster analysis and adjustment, the water receiving area in Henan Province was divided into three eco-hydrological zones, and each eco-hydrological zone was named. The specific naming principle is: geographical location+hydrological characteristics+influence degree of human activities. Among them, the geographical location is represented by the geographical location of most counties (cities) in the eco-hydrological region of Henan Province; Hydrological characteristics are the comprehensive reflection of groundwater depth, precipitation depth, runoff depth, water surface evaporation and other indicators, which are divided into three levels: level water, little water and water shortage; The influence degree of human activities is a comprehensive reflection of the ratio of cultivated land, woodland, grassland, water area, construction land, unused land and soil erosion area, which is divided into three levels: intensity, moderate and light activity.

After calculation, the average index value of each eco-hydrological area in Henan water receiving area of the first phase of the Middle Route of South-to-North Water Transfer Project is shown in Table 4.4.

Table 4.4 average index Value Table of Eco-hydrological Zone in Henan Water Receiving Area of the Middle Route of South-to-North Water Transfer Project.

For the convenience of naming, the hydrological characteristics of each eco-hydrological area are measured by the difference between evaporation and precipitation; The degree of human activities is measured by the area occupied by cultivated land and construction land. See Table 4.5 for specific standards.

Table 4.5 Naming Standard Table of Eco-hydrological Zone in Henan Water Receiving Area of the First Phase of the Middle Route of South-to-North Water Transfer Project

According to the above naming principles and zoning results, the ecological hydrological regionalization results and zoning map of Henan water receiving area in the first phase of the Middle Route of South-to-North Water Transfer Project are shown in Figure 4.5 and Table 4.6.

Fig. 4.5 Schematic diagram of eco-hydrological regionalization of Henan water receiving area in the first phase of the Middle Route of South-to-North Water Transfer Project.

Fig. 4.5 Eco-hydrological Zoning Map of Middle Route of South-to-North Water Transfer Project 1 Henan Water Receiving Area

Table 4.6 Results of Eco-hydrological Regionalization of Henan Water Receiving Area in the First Phase of the Middle Route of South-to-North Water Transfer Project

Partition overview

4.3.2.1Ⅰ Water shortage intensity eco-hydrological active area in south-central Henan Province

The geographical location of this area is located in the south-central part of Henan Province, and the terrain is stepped. This area includes Dengzhou, Xinye, Sheqi, Tanghe and Fangcheng in Nanyang, Henan Province, Shangshui in Linying, Yancheng and Zhoukou in Luohe, Yexian, Baofeng and Jiaxian in Pingdingshan, Xuchang, Xiangxiang, Yuzhou and Changge in Xuchang, Xinzheng, Zhongmou and Xingyang in Zhengzhou and wen county and Wuyi in Jiaozuo. This area is located in the transition zone from subtropical zone to warm temperate zone, and belongs to the typical semi-humid climate of monsoon continent, with four distinct seasons, abundant sunshine and rainfall. The average elevation is 90.93m, the average groundwater depth is 4.74m, the average precipitation depth for many years is 724.20mm, the average water surface evaporation for many years is 927.35 mm, and the evaporation-precipitation is 203. 15mm, so the hydrological characteristics belong to water shortage. The proportion of cultivated land is significant, followed by construction land. Cultivated land accounts for 57.84% of the total area, construction land accounts for 3 1.67%, and cultivated land+construction land accounts for 89.5 1% of the total area. The degree of human activity belongs to intensity.

Moderately active eco-hydrological region with water shortage in the middle Arctic of 4.3.2.2 Ⅱ in central Henan Province.

The geographical location of this area is located in the north-central part of Henan Province, and the terrain is stepped. This area includes Xiuwu County in Jiaozuo City, Henan Province, Huixian County in Xinxiang City, Weihui County and Qixian County in Hebi City. The climatic conditions in this area are the same as those in Area I, with an average elevation of 80.33m, an average groundwater depth of 8.5m, an average annual precipitation depth of 627.29mm, and an average annual water surface evaporation of118.18 mm. Evaporation-precipitation of 490.89mm is extremely short of water. The proportion of cultivated land is significant, followed by construction land. Cultivated land accounts for 45.88% of the total area, construction land accounts for 2 1.24%, and cultivated land+construction land accounts for 67. 12% of the total area. Human activities are moderate.

4.3.2.3 ⅲ active eco-hydrological region with extreme water shortage intensity in northern Henan Province

The geographical position of this area is in the north of Henan Province. This area includes Xun County of Hebi City, Puyang County of Puyang City, Anyang County of Anyang City, hua county, Tangyin and Neihuang. The climatic conditions in this area are the same as those in Area I ... The average elevation is 66.57m, the average buried depth of groundwater is 14.36m, the average annual precipitation depth is 569.62mm, and the average annual water surface evaporation is1054.43 mm. Evaporation-precipitation is 484.8 1mm, which is characterized by extreme water shortage. The proportion of cultivated land is significant, followed by construction land. Cultivated land accounts for 66.56% of the total area, construction land accounts for 26.55%, and cultivated land+construction land accounts for 93. 1 1% of the total area. The degree of human activity belongs to intensity.

summary

Based on the comprehensive analysis of the spatial differentiation characteristics of eco-hydrological conditions in Henan water receiving area of the first phase of the Middle Route of South-to-North Water Transfer Project, the 12 zoning index was selected. Taking 32 county-level cities (districts and counties) involved in the water receiving area of Henan Province in the first phase of the Middle Route of South-to-North Water Transfer Project as a unit, the database was established by using the index system value of eco-hydrological regionalization, and the clustering analysis was carried out by using the zoning method combining qualitative and quantitative methods. Finally, the eco-hydrological regionalization scheme of Henan water receiving area in the first phase of the Middle Route of South-to-North Water Transfer Project is put forward, that is, the Henan water receiving area in the first phase of the Middle Route of South-to-North Water Transfer Project is divided into three eco-hydrological regions, namely: ⅰ. the eco-hydrological active region with water shortage intensity in central and southern Henan; Ⅱ. Eco-hydrological region with moderate water shortage in the Central Arctic of Henan Province: Class III active eco-hydrological region with extreme water shortage intensity in northern Henan Province. The results of zoning can lay a foundation for the in-depth evaluation of the eco-environmental impact benefits of the water-affected areas in Henan Province in the first phase of the Middle Route of South-to-North Water Transfer Project, and provide an important basis and platform for the eco-environmental protection in local water resources planning and sustainable management.

A comprehensive analysis of the groundwater variation trends in three eco-hydrological areas in the study area shows that in recent years, there is a serious shortage of water in this area, frequent human activities, over-exploitation of groundwater and increasing groundwater depth year by year. This is due to the long-term serious shortage of surface water resources in this area and the increasing demand for water for economic and social development, which leads to serious over-exploitation of groundwater. Although some measures have been taken in various parts of the receiving area, due to the lack of alternative water sources, the groundwater in the receiving area will still be over-exploited and will continue to deteriorate before the opening of the middle route of South-to-North Water Transfer Project. It is urgent to solve the water supply problem in these areas as soon as possible. With the approach of the water supply target, it is particularly urgent and important for all parts of the water receiving area to make a good connection of policies and regulations on the utilization of various water sources, such as surface water and groundwater, foreign water and local water, especially to strictly control the exploitation of groundwater to make room for the North Water Transfer Project.