Correlation analysis of agricultural non-point source pollution and water environment change in Erhai Lake watershed
LU Zhonghui1,2， YU Bin1， ZHANG Hui1， YANG Zhen1
1.School of Urban and Environment Science， Central China Normal University， Wuhan 430079； 2.School of Urban and Environment Science， Huaiyin Normal University， Huaian， Jiangsu 223300
Abstract：Along with the effective control of point source pollution， agricultural non-point source pollution has become the main pollution source of lake water environment. Based on the equivalent standard pollution load method and the relevant survey data， this paper calculates discharges of agricultural non-point source pollution in the Erhai Lake watershed during 2006～2014， and then， using the grey correlation analysis method， correlations are studied between agricultural non-point source pollution and water environment in the Erhai Lake watershed. The research results show that： firstly， the total discharges of agricultural non-point source pollution are 8303.63 t， amount to equivalent standard discharges of COD， TN and TP as 325.85， 1371.29， and 420.10 m3/a， respectively， which indicates that TN is the main influence factor for pollution； secondly， the correlation between livestock and water environment is 0.71， and the correlation between crop farming and water environment is 0.63， which show that the influence of agricultural development is relatively significant for water environment. In detail， the correlations of garlic， rice， cattle and pig are 0.70， 0.69， 0.74， 0.69， and the contribution rates are 10.90%， 9.35%， 35.09%， and 13.19%， respectively； thirdly， from the perspective of spatial distribution， the north area are key pollution source areas， such as Sanying town， Yousuo town， ZiBi lake town， besides， the variance of non-point source pollution was non-balanced. According to the above data， the future agricultural development of Erhai Lake watershed is discussed in view of water environment protection strategy.
2017, Vol. 51 
