Abstract:

The relationship between land use and water quality is one of the important components of land use environmental effects research.Based on monitoring water quality and land use data,this paper focused on quantitative relationships between land use pattern and water quality in Chaohu Lake basin.Firstly with the help of GIS spatial analysis tool,strip types of contributing zones with different buffer radii were developed around the monitoring sites for water quality assessment,and the proportions of four types of land use types were extracted from the buffer zones.Then correlation and redundancy analysis (RDA) methods were used to analyze the relationship between water quality and land use patterns within buffer zones,and a comparison between mountainous areas and flat areas was made. Results showed that the land use structure in the river side area in Chaohu Lake basin had great impacts on water quality parameters.Urban construction land showed negative effects on water quality,and was the dominant factor for river pollution in Chaohu Lake basin.The forestland exhibited a significant positive relation with water quality,especially with CODMn and NH3N.It suggested that the closer forestland tend to improve water quality.The impacts of cultivated land on the river water quality were complicated. In addition,under different terrain conditions in Chaohu Lake basin,there were some differences in the way and to the degree of land use influencing the variables of water quality in the same contributing zone scale.RDA demonstrated that there existed obvious scale effect caused by different land use types.The study results should provide practical guidelines for the management of water environment in Chaohu Lake basin