北京市三角形剖面堰水位推流应用研究

Research on Discharge Calculating for Water Stage at Triangular Cross-section Weirs in Beijing

为解决河道小水等生态流量的监测难题,实现水资源的精细化管理,北京市在部分河道断面采用三角形剖面堰使水位流量单值化,并开展堰上水头连续监测,通过典型断面不同水位流量的现场精测,与三角形剖面堰水位流量关系理论线进行比对分析,发现堰上水头在低水区间流量实测值与理论值偏差在误差范围内,因此可在小水时利用理论线进行水位推流、中高水利用率定线进行水位推流。三角形剖面堰可推广应用于北方典型河道,满足防洪、景观、水资源、水质考核等要求,更有助于生态流量、海绵城市项目典型断面等水量监测。

In order to solve the problem of monitoring low ecological flow and realize the fine management of water resource,this paper studied the relationship between the water stage and discharge by triangular weirs at some stream cross-sections in Beijing.The water stage at the weirs were measured continuously.The comparison between the measured results and theoretical relationship of the water stage and discharge at triangular weir cross-sections shows that the flow head of the weir in the low water interval deviated from the theoretical value within the the reasonable range.Therefore,the small flow could be calculated with this theoretical relationship curve and the medium or large flow could be calculated with the calibrated relationship curve.These weirs with triangular cross-sections could be widely applied to some typical streams that meet the requirements of flood control,water resources and water quality evaluation,which also contribute to monitor the ecological discharge at some typical cross-sections of sponge-city project.