Preliminary study on relationship between urban built-up land and water quality in the Jiulong River Basin

Remote Sensing (RS) was integrated with Geographical Information System (GIS) technique in this study to explore the spatiotemporal change of urban built-up land and linkage between percentage of urban built-up and chemical Permanganate index (COD_Mn), Ammonia (NH₄⁺-N), total phosphorus (TP) concentrations in the Jiulong River Basin, Southeast China over the period 1986-2007. Percentage of urban built-up land tend to increase over 1986-2007 for 18 sub-watersheds. The percentage for most sub-watersheds nearly doubled in 2007. The percentage of urban built-up land is positively correlated with COD_Mn, NH₄⁺-N and TP, with coefficients R² 0.699, 0.818 and 0.787, respectively. The percentages of urban built-up land are positively correlated with COD_Mn, NH4 +-N and TP in both two seasons. Urban built-up land is better correlated with water quality in wet season than in dry season.