胶州湾氮、磷非点源污染负荷估算及时空分析

Estimation of N,P Non-Point Source Pollution Loads and Analysis of Spatial and Temporal Characteristies in the Jiaozhou Bay

考虑"陆源产生-河流输移-入海输出"的整体过程,根据土地利用、农业人口和畜禽养殖等数据,利用输出系数模型(ECM)模拟估算胶州湾海岸带2000—2013年氮、磷非点源污染负荷及其时空分布特征,并通过对比河流入海实测值与模型模拟结果,获取氮、磷非点源污染入海系数。结果表明:胶州湾海岸带各入海河沿岸氮、磷负荷年际下降趋势明显,空间上则呈现出"北高南低",耕地和农业人口是主要污染源;氮、磷入海通量与陆源污染负荷分布规律一致,氮、磷污染的入海系数均在0.6以上。河流及其流经区的空间异质性导致入海系数的差异化,其自然净化过程会对氮、磷污染物造成损失。因此为有效地缓解胶州湾海岸带非点源污染现状,应将源头控制、过程修复与末端治理有机结合起来。

This paper considered the overall process of “terrestrial production-river transport-sea output”. Based on the data of land use, agricultural population and livestock and poultry breeding, the non-point source pollution of the Jiaozhou Bay Coastal Zone from 2000 to 2013 was analyzed by using the export coefficient model. The actual monitoring value of the river estuary and the model results were compared and analyzed. The results showed that the load of non-point source pollution of nitrogen and phosphorus along the Jiaozhou Bay Coastal Zone decreased obviously, and the spatial variation trend was “north to south”. The agricultural population and the cultivated land were the most important sources of the non-point source pollution in the Jiaozhou Bay Coastal Zone; The flux of nitrogen and phosphorus into the sea was consistent with that of non-point source pollution of terrestrial nitrogen and phosphorus, and the nitrogen and phosphorus non-point source into the sea coefficient were above 0.6. The spatial heterogeneity of the river and its passing area leads to the difference of the non-point source sea-going coefficients of nitrogen and phosphorus. During the process of transiting into the sea, the natural purification process of the river ecosystem will cause losses to nitrogen and phosphorus pollutants to a certain extent. Therefore, in order to effectively improve the pollution status of the Jiaozhou Bay Coastal Zone, the source control, process control and end treatment should be combined to control the nitrogen and phosphorus non-point source pollution.