喀斯特小流域复杂景观中水质状况

以红枫湖流域周边一个受人为活动严重影响的农田源头溪流-王家寨小流域为研究对象,设置11个监测点研究硝酸盐（NO3-N）、氨态氮（NH4＋-N）、溶解性无机磷（PO4--P）、总磷（TP）和总悬浮物（TSS）在复杂景观中的变化状况。降雨后采样水中氮、磷含量明显低于雨后的地表积水,地表积水受各种影响,水质降低。水塘型湿地,其丰水期的PO43--P、TP、SS高于枯水期,与水循环条件较好的流水溪流还是存在明显的区别。从平均值来看,枯水期地表水和地下水TP都超过5级水质标准。水质与＂源＂景观的关系不明显,说明喀斯特小流域中复杂的景观结构对氮磷的截留作用。

Water quality analysis of complicated landscape in karst watershed

The water quality of complicated karst landscapes was investigated for three years in a agricultural head water stream which was greatly modified by human activities, located in Wangjiazhai of Qingzhen city, Guizhou Province, China. The NH4＋-N, NO3-N, PO4--P, total phosphorus （TP） and total suspended solids （SS） were measured for evaluation of water quality at 11 spots. Results showed that concentrations of nitrogen and phosphorus in storm water runoff were smaller than that of the earth’s surface seeper whose water quality fall obviously by some influences. Concentrations of PO43--P、TP、SS in pond reach were bigger in high flow season than that of in low-flow period, indicating that its water quality was worse than that of stream runoff. The average concentrations of TP of surface water and ground water were lower than the Fifth Water Quality Standard whether in high flow season or in low-flow period. The inapparent regression relations between indices of water quality and the area of source landscape suggested the retention of complicated landscape structure to the nitrogen and phosphorus.