Effects Of Land Use Change On Non-point Source Pollution In Naoli River Basin Sanjiang Plain

How to understand non-point source pollution scientificly and control effectively has become one of the urgent issues need to be solved in Chinese environmental protection field,unreasonable land use is the key element to cause non-point source pollution.This paper take Naoli River Watershed Sanjiang plain as the study area.From the influence of non-point source pollution from land use,through the use of land use digital reconstruction technique and GIS technique;analysis the land and spatial and temporal patterns of several key periods since 1954 in Naoli River Watershed Sanjiang plain;Using the sampling method combined with field monitoring and indoor laboratory,to analysis the content of the main form of N,P from non-point source pollutants and key climate parameter;Taking different ages and different land use as the premise,to analysis the spatial and tempral variation of non-point source pollution factors.Getting the cumulative ecological effects from long-term land use patterns of non-point source by using ArcSWAT model to simulate quantitativly,to predict the degree of non-point source pollution is affected by land use change in the future.Laboratory analysis show that the content of N,P in different land use is roughly paddy > dry land > wet land > woodland.The law of content of nutrient salt of N,P from water with basin distribution trend is middle-downstream > middle stream >downstream > middle-upstream > upstream.The content of N,P of soil is roughly similar with the distribution trend of corresponding different basin.Most of the water samples have the high content in the abundant water period,probably because of the heavy rainfall in the abundant water period,N,P in soil run into water bodies with runoff.This study provides support of mechanism of non-point source pollution,and has the important practical significance to promote the level and efficiency of our country non-point source pollution control,improve water quality and formulate river basin water environment quality goal.