Flood analysis using Hecras

Question

大家好，当我在Hec-ras中导出几何图形并在hec-ras中计算稳态流动分析时，我正在执行基本的Hecgeo-ras教程，这给了我这个错误“需要在第一个工作站上指定水平配向n值”有人可以帮我这个忙吗？

Answer 1

When using HEC-GeoRAS, it is the user's responsibility to assign Manning's n coefficients to each cross section. That is, unless you first created a LandUse feature class in the map document. If you created an empty LandUse feature class then the "N_Value" fields will be blank and since the calculations in the program start at the first station, you will see an error just as you stated.

From the Purdue University Tutorial : To assign Manning's n to cross-sections, click on RAS Geometry->Manning's n Values->Extract n Values. Confirm LandUse for Land Use, choose N_Value for Manning Field, XSCutLines for XS Cut Lines, leave the default name Manning for XS Manning Table, and click OK.