Response of river nitrogen and phosphorus output to spatial land use loads in the multi-watershed of the Xinjiang River
[Objective]In recent years,the problem of water pollution in the basin has become more and more prominent,and total nitrogen and total phosphorus have become one of the indicators of water pollution,and the change in river nitrogen and phosphorus concentration is influenced by the land use pattern of the basin to some extent,in order to guarantee the safety of the water environment in the Xinjiang River Basin,it is of great significance to carry out a study on the response to the nitrogen and phosphorus production of spatial loads of land use in order to judge the risk level of the basin,designate the priority treatment area and promote the adjustment of the land use structure.The study is of great significance in determining the level of risk of the basin,defining priority management areas,and promoting the adjustment of the structure of land use.[Method]Sixteen subbasins of the Xinjiang River Basin were selected as the study area,and Pearson's correlation analysis was carried out using GlobalLand 30 data,DEM data,river network data and total nitrogen and total phosphorus monitoring data of river sections in 2000 and 2020,referring to the theory of the source-sink pattern,building a spatial load ratio index of land use based on the Lorentz curve,and combining total nitrogen and total phosphorus concentration data for Pearson's correlation analysis.[Result]①The average values of the three types of spatial elements(relative elevation,slope and relative distance)and the comprehensive LWLI index did not exceed 0.3,indicating that the risk of nitrogen and phosphorus pollution in the current land use pattern of the watershed was low.②From the perspective of the contribution of three types of spatial factors to the pollution load,the results are shown as LWLIs>LWLIe>LWLId,indicating that relative elevation and slope have a more significant impact on the spatial pollution load of the watershed,so the type of land use located in the middle and high altitude and steep slope areas in the watershed should become the focus of attention.③The Pearson relationship between land use pattern and nitrogen and phosphorus output was analyzed from the perspective of the"source sink"land type structure and land use spatial load,and it was found that the land use spatial load ratio index had a higher correlation coefficient and a more significant correlation than the source sink area structure,which could more effectively characterize total nitrogen and total phosphorus loss in the watershed.[Conclusion]From the perspective of"source-sink",the theory of"source-sink"is applied to the analysis of spatial and temporal evolution of the spatial load of land use in the river basin,quantitatively analysing the relationship between the spatial load of land use and surface pollution in multiple river basins,providing a useful reference for the management of water pollution,and can be used as a basis for the study of the Xinjiang River Basin,and can also be used as a reference for the prevention and control of water pollution and optimization of the land use structure in the basin,and provides decision-making support for the improvement of the ecological environment and the quality of the water in the Xinjiang River Basin.
Xinjiang River Basinland use pattern"Source-sink"theorylandscape spatial load ratio indexlorentz curve theorynitrogen and phosphorus
国家科技期刊平台
NSTL
万方数据
