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水土流失是水体富营养化的一个重要源头。在三峡库区小江流域,定点监测了4类农地(水田、梯坪地、<25°坡耕地、>25°坡耕地)的水土流失量,并于2008年在渠口、养鹿、高阳、黄石、双江及河口(参照)6个断面采水样进行水质调查。研究结果表明:坡耕地是小江流域水土流失的主要策源地;农地水土流失导致的氮、磷流失对小江水体的富营养化贡献很大,流失的TN、TP分别高达675.76,69.03 t/a;小江TN浓度主要受水土流失和长江TN浓度的共同制约,峰值为5.31 mg/L(渠口)出现在7月份;小江TP浓度主要受水土流失和长江水位的共同制约,各断面的最小值均出现在7月份,最小值为0.03 mg/L(渠口)。总体而言,小江处于中营养到富营养状态,4月份较容易发生水体富营养化,7月份和11月份磷是水体富营养化的限制因子。
Soil and water loss is an important source of water eutrophication. In the Xiaojiang River Basin in the Three Gorges Reservoir area, the amount of soil and water loss in four types of agricultural land (paddy field, steep ground, <25 ° sloping farmland,> 25 ° sloping farmland) was monitored in a fixed manner. In 2008, , Huangshi, Shuangjiang and estuaries (reference) 6 sections of water samples for water quality survey. The results showed that sloping farmland was the main source of soil and water loss in Xiaojiang River Basin. The loss of nitrogen and phosphorus caused by soil erosion in farmland contributed greatly to the eutrophication of Xiaojiang River. The TN and TP losses were as high as 675.76 and 69.03 t / a, respectively . The TN concentration in Xiaojiang River was mainly controlled by soil erosion and TN concentration in the Yangtze River. The peak value was 5.31 mg / L in July. The TP concentration in Xiaojiang River was mainly controlled by soil erosion and the Yangtze River water level. The minimum value All appeared in July, the minimum value of 0.03 mg / L (drainage mouth). Overall, Xiaojiang is in a state of nutrient eutrophication, which is prone to eutrophication in April and phosphorus in July and November as a limiting factor for the eutrophication of water bodies.