里下河地区水质模型的开发与应用

Development and Application of Water Quality Model of Lixiahe Region

江苏位于江淮沂沭泗下游,中部和南部以平原河网地区为主,区内圩区密布,水情、工情复杂,河网流速缓慢,水环境容量较小。以江苏省里下河地区为典型研究区域,在里下河地区水文水动力模型的基础上,根据区域河网水流运动和污染物排放、迁移特点,构建了分布式污染负荷模型以及零维湖泊、一维河网相结合的水质模型,实现了区域水量水质耦合模拟计算,模拟结果良好。研究表明,里下河地区主要污染物排放中,点源污染60%~70%来自于生活污水,面源污染30%~40%来自于旱地径流,受河网沟通等因素影响,中部和北部地区水质劣于南部地区。模型对于探索区域污染物的产生、迁移和转化及其时空分布特征具有支撑作用,并对其它类似平原河网地区水质模型的开发应用提供参考。

Jiangsu Province is located in the lower reaches of the Yi-Shu-Si River in Yangtze-Huaihe Region.Its central and southern regions are dominated by plain river network.And the region is featured with densely covered polder,complex water conditions and working conditions,slow river network flow rate,and small water environment capacity.Taking the Lixiahe Region in Jiangsu Province as a typical example,a distributed waste load model and a water quality model that combines zero-dimensional lake and one-dimensional river network are constructed based on the hydrodynamic model of the Lixiahe Region,and the characteristics of water flow movement,pollutant discharge and migration of regional river network,to achieve the coupled simulation calculation of regional water quantity and quality with good simulation results.The research shows that in the discharged major pollutants in Lixiahe Region,60%~70% of point source pollution comes from domestic sewage,and 30%~40% of non-point source pollution comes from dry land runoff.Due to the factors such as river network flow,the water quality in the central and northern regions is poorer than that in the southern region.The model serves as a supporting role in exploring the generation,migration,transformation and spatial&temporal distribution characteristics of regional pollutants,and a reference for the development and application of other water quality models in similar plain river network.