Study on phosphorus loss and influencing factors in the water source area

Maintaining drinking water security is a global issue, and phosphorus is a limiting factor affecting drinking water quality. Hence, this study took Fushi Reservoir as a test area, and set up field runoff observation plots around the reservoir catchment, which is covered by moso bamboo stands. Through field observation, the vertical variation of phosphorus loss in different stands of moso bamboo was initially studied. The results showed that: (1) For the vertical dimensions (atmospheric rainfall, stemflow, throughfall, surface runoff) from high to low, the loss of total phosphorus (TP) increased, and the proportion of dissolved phosphorus increased from 29.29% (atmospheric rainfall) to 62.76% (surface runoff). (2) Different rainfall factors had various impacts on phosphorus loss at the different vertical levels. The accumulation of rainfall had the greatest impact on surface runoff TP loss, with the correlation coefficient reaching 0.994 (P < 0.01), while surface runoff particulate phosphorus loss was mostly affected by the average rainfall intensity. (3) Modifying the forest structure in water source areas can reduce the loss of TP via stemflow and throughfall, but the effect on surface runoff TP loss is variable. Thus, it is expected that this novel study can serve as a reference for improving the environmental quality of water source areas, and help in reducing phosphorus loss and controlling non-point source pollution. (C) 2021 International Research and Training Center on Erosion and Sedimentation, China Water and Power Press, and China Institute of Water Resources and Hydropower Research. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.