官厅水库及其上游流域水环境容量研究

Analysis of water environmental capacity of Guanting Reservoir and its upstream basin

中国北方水系普遍水量较小,污染较重。水环境容量的测算可以为水污染防治提供科学依据。文中以官厅水库及其上游流域为例,依据流域水文特征选取合适的水环境容量模型,分别求出流域内各功能区段水环境容量。结果表明:流域内COD、NH3-N的水环境总容量分别为5097.82 t/a,268.18 t/a;相比于污染负荷,水环境容量明显偏小;不同功能区段水环境容量差别较大;水环境容量偏小的主要人为因素在于上游流域大兴水利工程,农业用水量大且用水效率低;污染负荷较大的主要原因是流域内产业结构不合理,农业面源污染未得到有效控制。

Water basins in Northern China have generally small water quantity and were polluted heavily. The calculation of water environmental capacity can provide a scientific basis for water pollution control. Taking the Guanting Reservoir and its upstream basin as an example,according to the hydrological characteristics of the basin,one- dimensional steady- state water quality model was chosen to calculate the water environmental capacity of each functional zone of in this basin. Results showed that the total water environmental capacity of COD and NH3- N in the basin were 5097. 82 t /a,268. 18 t /a respectively; compared with the pollution load,water environmental capacity was significantly smaller; the water environmental capacity of different functional zones was quite different; large numbers of water conservancy projects in the upstream basin and high consumption but low efficiency of agricultural water led to the small water environmental capacity; improper industrial structure and poor control of agricultural non- point source pollution were the leading causes of the large pollution load.