基于分布式水文模型的徒骇河河流生态需水量预测研究

流域的气候、植被和土地利用方式等变化对河流生态需水具有决定性作用.以徒骇河刘桥闸控制区域为例,定量估算了现状河流生态需水量,并以流域分布式水文模型SWAT为工具,预测了各水平年不同保证率下不同生态恢复目标的各月河流生态需水量.结果表明,现状年河流生态需水量为81.09×106m3,其中自净需水是河流生态需水的主要组成部分,因此保证徒骇河生态需水的关键是污染源的治理.拟通过减少点源排放、减少灌溉水量、减少农药化肥施用及增加干流两边的缓冲带等措施,使污染源得到进一步控制,预测2015年、2020年、2030年河流生态需水量不断减少,丰水年份河流天然径流量能满足河流生态需水要求,但枯水年份仍存在较为严重的生态缺水问题,需要对河流进行生态补水.

Prediction of ecological water demand of Tuhai River using a distributed hydrological model

Climate, vegetation and land use changes in a watershed play a decisive role in the river's ecological water demand. In this study, we calculated the river's current ecological water demand taking Tuhai River upstream above Liuqiaozha Station as an example. The river's ecological water demand was predicted under different hydrological frequency years and ecological restoration plans, using the distributed hydrological model SWAT (Soil and Water Assessment Tool). The results showed that current river's ecological water demand was 81.09×10⁶m³, of which self-purification water demand was a major part. Therefore, the key to ensure the ecological water demand was to decrease point source pollution, the irrigation water quantity and chemical pesticide and fertilizer usage, while increasing the width of buffer zone along the river. Through the implementation of different management measures, the sources of pollution will be controlled. As a result of the pollution control, the river's ecologic water demand in the year 2015, 2020 and 2030 is predicted in a declining trend. The ecological water demand in rich precipitation years is satisfied by the natural river flow. In the dry years, it is necessary to supply water to the river, due to a serious shortage of ecological water.