SPATIO-TEMPORAL PATTERN EVOLUTION OF NON-POINT SOURCE PHOSPHORUS LOADS IN CHAOHU LAKE BASIN (ANHUI PROVINCE, CHINA) UNDER DIFFERENT LAND USE PATTERNS

Non-point source (NPS) pollution is an important source of lake eutrophication, the phosphorus (P) is one of the main elements of NPS pollution, and land use change has an important influence on NPS pollution load. Most previous studies focused on a single phase and did not analyze the internal structure of land use. In this study, six natural river basins such as the Hangbu River Basin were selected as the study area in Chaohu Basin, China Based on the Sediment Delivery Distributed (SEDD) model, the NPS P load was simulated from 2000 to 2015, and the characteristics of land use change were depth analyzed at the same time to discuss the mechanism of land use pattern on NPS P load under longterm sequence. The main result are as follow: the NPS P load intensity was positively correlated with FL (forest land) area, in the whole study area, the correlation coefficient between NPS load intensity and FL area was 0.67, and the NPS P load intensity was negatively correlated with arable land (AL), construction land (CL) and wetland (WL) area, and the correlation coefficients were 0.56, 0.26 and 0.14 respectively. On the other hand, the internal structure of land use is also affecting NPS P load, the Fractal Dimension Index Mean (FRAC) was positively correlated with NPS P loss intensity, and the correlation coefficient is 0.56. Compared to the AL, FL and CL are more easily affected by FRAC. The optimization of land use spatial layout plays an important role in alleviating NPS pollution particle state.