基于等容瞬时单位线的水文模型研究
A hydrological model based on isovolumetric instantaneous unit hydrograph
闫宝伟 1唐仪伟 1刘昱 2古东霖 1孙明博1
作者信息
- 1. 华中科技大学 土木与水利工程学院,湖北 武汉 430074;华中科技大学 数字流域科学与技术湖北省重点实验室,湖北 武汉 430074
- 2. 长江勘测规划设计研究有限责任公司,湖北 武汉 430010
- 折叠
摘要
流域下垫面空间分布的不均匀性对径流的形成有较大影响,流域蓄水容量曲线解决了流域产流空间异质性的问题,但在采用瞬时单位线进行地表汇流计算时,又将其作为空间分布均匀的净雨处理,局部产流并没有实现局部的汇流.考虑汇流时间与蓄水容量的空间相关性,通过Copula函数构造二者的联合分布,以条件概率的形式反映不同蓄水容量处汇流时间的空间分布特征,进而以等蓄水容量为计算单元,提出了等容瞬时单位线的概念,相当于采用变单位线的方式计算单元产流量的地表径流,从而可以实现局部产汇流计算过程的统一.由此,创建了基于等容瞬时单位线的水文模型IIUHH,并根据Copula函数的类型构建了多种形式的IIUHH,最后选择清江上游作为案例进行验证.结果表明:Clayton型的IIUHH在研究区域表现更优,相比于新安江模型,Nash效率系数可以提高4%～12%,Kling-Gupta效率系数可以提高13%～27%,洪峰相对误差则可降低26%～36%,较大程度上提高了洪峰和洪水过程的模拟精度.研究成果可为流域高精度径流预报提供技术支撑.
Abstract
The spatial heterogeneity of the underlying surface in a basin has a significant impact on runoff generation.The water storage capacity curve can effectively address the issue of spatial heterogeneity in runoff generation.When the instantaneous unit hydrograph is used for calculating surface runoff confluence,it is considered as the net rain with uniform spatial distribution.In this scenario,local runoff does not account for local confluence.In this paper,the spatial correlation between confluence time and water storage capacity was considered,and their joint distribution was constructed by a Copula function.The spatial distribution characteristics of confluence time at various storage capacities were manifested in the form of conditional probability.Furthermore,a concept of an isovolumetric instantaneous unit hydrograph was proposed by using the isovolumetric water storage capacity as the calculation unit.This approach was equivalent to the variable unit hydrograph method for calculating the confluence of surface run-off,thereby unifying the calculation process for local runoff and confluence.Therefore,an isovolumetric instantaneous unit hydro-graph based hydrological model(IIUHH)was constructed,and various forms of IIUHH were developed based on the type of Cop-ula function.Finally,the Qingjiang River upstream was selected as a case study.The results showed that Clayton Type IIUHH per-formed better in the study area.Compared with the Xin'anjiang model,the Nash efficiency coefficient can be increased by 4%to 12%,the Kling-Gupta efficiency coefficient can be increased by13%to27%,and the flood peak relative error can be reduced by 26%to 36%.The simulation accuracy of flood peak and flood processes has been significantly enhanced.The research results can be used for high-precision runoff prediction in a basin.
关键词
等容瞬时单位线/水文模型/蓄水容量/空间相关性/新安江模型/清江Key words
isovolumetric instantaneous unit hydrograph/hydrological model/water storage capacity/spatial correlation/Xin'anjiang model/Qingjiang River引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据