基于DEM数据的河道水动力过程数值模拟  

River cross-section extraction from DEM for one-dimensional hydrodynamic modeling

作　　者：俞茜[1] 陈永灿[1] 朱德军[1] 刘昭伟[1] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水力发电学报》2014年第3期133-137,157,共6页Journal of Hydroelectric Engineering

基　　金：国家自然科学重点基金资助项目(51039002);清华大学自主科研计划(20121088082)

摘　　要：河道横断面形状数据是应用数值模型模拟水动力过程必不可少的基础数据之一,然而在我国很多河道缺少断面数据,若进行野外补充测量,须要耗费大量的人力、物力,而且耗时较久。数字高程模型(DEM)数据可以免费下载,获取途径方便,但若直接通过DEM获取断面数据存在两个问题,即水面上数据不精确和无法得到水下地形,就此,作者对获得的DEM数据进行校正以获取河道水面以上断面数据,同时本文首次提出采用三次样条对水面以上数据插值得到水面以下断面数据,从而合成完整的河道断面。将所得断面与实测断面同时代入一维水动力和水质模型THU-River1H进行模拟计算,两者模拟得到的流量和水位过程均吻合良好。本文证明了当径流流量较大或水位较高时,若缺少河道横断面数据,可将基于DEM获取的河道断面代替实测断面进行一维水动力计算,所得结果具有较高的可信度。Cross-sectional shape data are prime input to numerical river hydrodynamic models, playing an essential role in simulation of discharge and water level. However, many rivers lack measurement of cross sections and their field survey is painstaking and time-consuming. This paper describes an approach to synthesizing river cross-sections based on the Digital Elevation Model （DEM） data which can be obtained by free download from the internet. Imprecise DEM data and deficiency of underwater data are two problems. In the approach, the DEM data are extracted and then revised with measured data to construct a shape for the upper part of each cross section, while the shape of lower part or underwater channel bed is calculated by interpolation with the Kochanek-Bartels splines. To verify this new approach that is used for the first time, both the extracted cross sections and the measured ones were used in simulation of flooding in the lower reach of the Pudu river with a one-dimensional hydraulic model THU-RiverlH. Good agreement between the two results suggests that the extracted cross sections can be used for the case of lacking topographic data in hydrodynamic modeling.

关 键 词：水动力学 河道横断面 DEM THU-River1H 

分 类 号：TV133[水利工程—水力学及河流动力学]