栅格新安江模型在陕西省大河坝流域中的构建与应用

Construction and Application of Grid-Xin’anjiang Model Within Daheba Watershed in Shaanxi Province

以陕西省汉江支流大河坝流域为研究区域,通过DEM数据分析、地貌特征参数提取等工作,构建了基于栅格的新安江水文模型,模拟分析了流域的径流过程以及自由水含量空间分布的动态变化情况。为验证构建的栅格新安江模型的可靠性,利用大河坝专用水文站2011—2014年7场次实测洪水资料进行洪水模拟验证,结果表明:洪峰流量的模拟误差基本能够控制在20%以下、峰现时间误差均在3 h以内、不确定系数达到0.78以上,表明本次构建的栅格新安江模型能够较为准确地对洪水过程进行模拟;同时以2013年7月16日和25日2场次洪水过程为例,对模拟的自由水的空间分布动态变化进行了分析,结合自由水含量的物理意义,降雨过程的发展情况以及流域出口的洪水过程精度评定可知构建的栅格新安江模型可以较为准确地模拟出流域中自由水含量空间分布的动态变化。

Taking Daheba watershed,the tributary of Hanjiang River in Shaanxi Province as the study area,this paper constructs the Grid-Xin’anjiang model through DEM(Digital Elevation Model)data analysis and geomorphic feature parameter extraction,applies it to simulate and analyze the runoff process of the watershed and the dynamic changes of spatial distribution of free water content,and carries out the flood simulation verification by the measured data of 7 flood in the special hydrological station of Daheba from 2011 to 2014 to verify the reliability of the constructed Grid-Xin’anjiang model.The results show that the simulation error of peak discharge can be controlled below 20%basically,the error of peak time is within 3 h,and the uncertainty coefficient is above 0.78,which indicating that the Grid-Xin’anjiang model can satisfactorily simulate the flood processes within Daheba watershed of Shaanxi Province.At the same time,taking the rainfall runoff process on July 16,2013 and July 25,2013 as an example,it analyzes the dynamic change of spatial distribution of free water content.As a result,combined with the physical meaning of free water content,the development of rainfall process and the evaluation of flood process precision at the outlet of the watershed,it can be concluded that the Grid-Xin’anjiang model can simulate the dynamic distribution of free water content accurately.