Study On Land-sea Overall Management Zoning About Nitrogen Pollution Of Bohai Sea Rim

Nitrogen pollution is a serious problem in Bohai Sea, which is mainly from terrestrial water pollution. Strengthen the control of nitrogen pollution in Bohai Rim and implementation of land-sea overall management is the key to solve the problem of nitrogen pollution of Bohai Sea. Implementation of land-sea overall management is based on zoning. In this paper, Bohai Rim is spatial extent, nitrogen pollution is object for study, following the natural process of water pollution, search for a way to solve Bohai Sea environment problem by land-sea overall zoning, which is significant for Bohai Sea environment management. Thesis contents and conclusions are as follows:(1) Using high resolution DEM and vector river data, through terrain revise technique and river correction technique, solve the problem of watershed extraction in plain ground. Through a process of refinement and generalization after defined of catchment unit and coast unit, clearly defined boundary in coastal area. Based on the method above,119watersheds is extracted in Bohai Rim.(2) An uneven distribution simulation of socio-economic data is implemented by land-use area weight method, and achieved socio-economic data transition between zoning systems. Compared witch traditional method, it presents more real spatial distribution, is more accuracy, shows more objective regional differences. Based on watershed area, spatial distribution analysis on TN and related socio-economic data is taken by land-use area weight method.(3) Sea area nitrogen pollution response zoning is carried out on the basis of spatial interpolation based on following field. Compared with common spatial interpolation methods, spatial interpolation based on following field presents more real characteristics of pollutant dispersion driven by sea fluid power, gains more accuracy. Sea area nitrogen pollution response zoning is analyzed based on the interpolation result. Analysis of contradiction between sea water management requirements and sea water status is taken on sea area nitrogen pollution response zoning. It is concluded that44%areas cannot reach the management requirement, which is significant difficult in some areas, different functional zones shows different characteristics, preserve area and protection area has large areas of low conformity, protection area and fishing area has very low conformity, contradiction areas is spatially concentrated. (4) It is finished land-sea overall zoning of Bohai Rim, which integrated source area and influence area of nitrogen pollution, provide spatial bases for land-sea overall management. Water quality management objective is defined which characterized as continuous and practical, and conformity between water quality objective and water quality status is improved. Management key points, strategies and suggestions are studied and listed in the end.