Relationships between land use patterns and water quality in the Taizi River basin, China

Using land use types and landscape metrics, as well as statistical and spatial analysis, we determined the relationships between land use patterns and river water quality in the Taizi River basin, China, during dry and rainy seasons in 2009. Correlation and multiple linear regressions indicated that vegetated areas had a positive contribution to river water quality and predicted total nitrogen during the rainy season. Built-up land use strongly influenced nitrogen and phosphorus parameters in river water. Agricultural land use was associated with most physicochemical variables and nitrogen during the rainy season. Landscape metrics during both seasons were significantly associated with river water quality. Shannon's diversity index was the primary predictor for chloride and ammoniacal nitrogen. Mean Euclidean nearest neighbor index defined ammoniacal nitrogen, orthophosphate, and total phosphorus during the dry season. Biological oxygen demand and permanganate index were expressed by Contagion during the rainy season. Factor analysis indicated that the river suffered organic, phosphorus, and nitrogen pollution and a zone dominated by agricultural and built-up land uses in the river basin tended to have worse water quality than other areas. The results provide a useful approach that uses landscape patterns to estimate water quality in rivers for water pollution control and land use management.