| Water ecological function zoning is the basis for the realization of “zoning,classification,grading and staging” management of the water environment in the basin,and is an important part of the water environment management technology system.Beijing is one of the regions with the fastest economic development in my country,but the contradiction between ecological environment and economic development is becoming more and more prominent.The level of control objectives and control measures have become the top priority.Taking Beijing as an example,this paper divides the first,second,third,and fourth water ecological function zones,analyzes the water ecosystems at all levels,and then proposes management and control goals and strategies at all levels.The research content of this paper mainly includes the following parts.Based on the DPSIR method(driving force-pressure-state-impact-response),this study preliminarily screened out the zoning indicators applicable to various levels of water ecological functions in Beijing.This method can systematically analyze the internal relationship between land,water,society,policy and other elements.Firstly,the spatial variation degree and spatial autocorrelation analysis of each environmental index data were carried out.The results show that elevation can exhibit greater spatial variability at large scales,and land use types and population density have greater variability at med ium scales.Therefore,the first-level division uses the elevation to extract the boundaries of the five major water systems in Beijing,and uses the water system elements as the first-level division index;The secondary zoning mainly reflects the impact of human activities on water ecology,and the zoning indicators are elevation and land use.The third-level zoning calculates the weight of the proportion of environmental elements in each sub-basin,and selects the proportion of forest land,slope,and river network density to reflect the characteristics of Beijing’s water ecological functions.From the perspective of protection needs,the fourth-level zoning mainly considers the location of sensitive water bodies and nature reserves in Beijing.(2)In this zoning process,the principle of genetics,the principle of regional connectivity,the principle of water-land consistency,the principle of watershed boundary integrity,etc.are mainly adopted,and the combination of "top-down and bottom-up" is adopted.method,carry out zoning from two aspects: land area and water area.The first and second-level areas are firstly divided according to the top-down driving mechanism of water ecological functions in the land area,and then Beijing is divided into 1085 sub-basins by using the Hydrology module of Arc GIS.Merge,complete the division of ecological function characteristics in the water area from bottom to top,so as to reflect the zoning principle of "combining water and land,and determining land by water".(3)There are 49 water ecological function zones in Beijing,including 5 first-grade zones,13 second-grade zones,30 third-grade zones,and 49 fourth-grade zones.The second-level partition corresponds to the habitat conditions,including two types of habitat damage areas and good habitat areas;the third-level partition is divided into different ecological function types,including four types: habitat maintenance area,urban support area,agricultural production maintenance area,and water conservation area.;The four-level division is mainly divided into two types of Beijing natural reserves and water-sensitive areas(five reservoirs).The Chaobai River Basin in the northern part of Beijing and the Daqing River Basin in the southern part of Beijing have good water quality and good water ecological conditions;the Jiyun River and Yongding River Basins are second;the North Canal Basin in the middle is poor.On the whole,there are certain differences in water quality and water ecosystem health in different water ecological function zones,and more targeted management and control measures are proposed. |
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