城市河流生态补水对水质影响研究

Study on the impact of ecological water replenishment on water quality in urban rivers

城市河流污染负荷高,枯水期基流短缺问题严重,生态补水是改善其水质的重要手段。为明确城市河道水质提升与生态补水水质水量间的响应关系,文章以南淝河为对象,基于一维水动力-水质耦合模型,提出了采用蒙特卡洛随机采样方法构建多情景工况开展生态补水分析的方法,并用于南淝河干流水质与不同补水工况、上游来水水质和水量的响应关系分析。研究表明:补水引入的优质水源可有效降低南淝河干流及入湖的氮磷浓度。由于下游沿河污染和支流的汇入,补水改善水质的影响从上游向下游逐渐减弱。干流水质浓度与补水水质呈比较一致的线性关系。在后续补水过程中应注重保障进入南淝河的水质。

Ecological water replenishment is an important way to improve the water quality of urban rivers with high pollution load and serious base-flow shortage during dry season.In order to clarify the response relation-ship between urban river water quality improvement and ecological replenishment water quality and quantity,based on the one-dimensional hydrodynamic and water quality coupling model,this study applied Monte Carlo random sampling method to construct multi-scenario ecological replenishment analysis in Nanfeihe River.The response of the water quality of the main stream of Nanfeihe River to different replenishment conditions,and the water quality and quantity of upstream influent was analyzed.Results show that the water quality of Nan-feihe River and to the Chaohu Lake can be significantly improved by the replenishment of high-quality water.Due to downstream pollution along the river and the inflow of tributaries,the influence of water replenishment to improve water quality is gradually weakened from upstream to downstream.A consistent linear relationship between the concentration of the main stream water and the replenishment water quality is found.It highlights that attention should be paid to ensuring the water quality of the Nanfeihe River.