基于能量转换的地貌单位线计算方法及应用  

Calculation method and application of the geomorphic unit hydrograph based on spatial energy conversion

作　　者：王文川[1] 赵延伟 徐冬梅[1] 刘昌军[2] 马强 Wang Wenchuan;Zhao Yanwei;Xu Dongmei;Liu Changjun;Ma Qiang(College of Water Resources,North China University of Water Resources and Electric Power,Zhengzhou 450046,China;ResearchCenter on Flood and Drought Disaster Reduction,China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]华北水利水电大学水资源学院,郑州450046 [2]中国水利水电科学研究院防洪抗旱减灾研究中心,北京100038

出　　处：《农业工程学报》2022年第8期135-142,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：河南省重点研发与推广专项(科技攻关)(202102310259,202102310588);国家自然科学基金项目(51509088);河南省高校科技创新团队项目(18IRTSTHN009)。

摘　　要：该研究基于能量转换原理构建汇流模型,针对中小河流汇流参数确定困难、汇流计算准确度低的问题,分析流域内水质点能量的空间分布,采用将重力势能转化为动能的方式估计地表水流速度,计算空间流速场并提取地貌单位线。采用分辨率30 m×30 m的数字高程模型(Digital Elevation Model,DEM)数据,将湖南省竹溪坡流域划分为57个计算单元,分别采用能量转换法和坡度雨强法提取了地貌单位线。构建了研究区的分布式模型,其中产流计算采用新安江模型,坡面汇流采用地貌单位线模型,河网汇流采用马斯京根法,对竹溪坡流域36场降雨径流过程进行模拟。采用统计方法分析汇流参数,对参数的取值范围进行了评估。结果表明,与坡度雨强法相比,基于能量转换方式的洪水模拟结果中,峰现时间误差不超过1 h的场次比例由30.5%提高到83.3%,确定性系数不低于0.9的场次由9场提升至17场,平均确定性系数达到0.89,显著提高了模拟精度。通过对断面流速进行统计分析,评估竹溪坡流域汇流参数取值范围为[0.008, 0.014],当参数在此区间浮动时,确定性系数不低于0.9的场次比例为44%~50%,与率定得到的结果接近。该方法物理意义明确,参数可以通过率定或者测量方式确定,为无资料地区汇流规律研究提供了一种可靠思路。Flood in small and medium-sized catchments can be characterized by the short concentration time, high flow velocity, fierce attack, and violent stage change. Mountain torrents also occur frequently in these small and medium-sized catchments. But, it is very difficult to carry out flood forecasting and early warning, due mainly to those located in the ungauged areas. Therefore, it is a high demand to improve the forecast accuracy in the operational hydrology, especially in the areas without enough measured data. In this study, an energy model was proposed to estimate the velocity of overland flow for the high accuracy in the simulation of flow concentration. Firstly, the spatial distribution of the energy was determined for the water particles in the basin. The gravitational potential energy was gradually transformed into kinetic energy using the iterative computation from the upstream to the downstream, according to the flow direction. Secondly, the spatial energy field was constructed considering the energy loss, and then the overland flow velocity was estimated to generate the spatial velocity field.Thirdly, the concentration time was calculated to count the number of grids, when the water particles on each grid reached the outlet of the watershed. Finally, the geomorphic unit hydrograph was generated to determine the relationship between the catchment area and concentration time. The study area was set as the Zhuxipo basin in Yiyang City, Hunan Province, China,located at the source of Yixi, a tributary of the Zishui River. The Zhuxipo basin was divided into 57 sub watersheds using Digital Elevation Model(DEM) data with a resolution of 30 m×30 m. A distributed model was then constructed to simulate 36 floods in the study area from 1984 to 2020. A Xinanjiang model, geomorphic unit hydrograph model, and Muskingum Routing were used to calculate the runoff generation, overland flow concentration, and river network flow concentration,respectively. The geomorphic unit hydrograph was also extracted by the Energy Conv

关 键 词：径流 流速 空间分布 洪水预报 地貌单位线 分布式水文模型 

分 类 号：TV124[水利工程—水文学及水资源]