farah.ahmad

Thank you Chris. I appreciate your help. I will check up this issue. Best regards, Farah

Chris, I appreciate your reply. As you said, modClark works if I define a user hyetograph. But this method overestimates the runoff in the watershed case of study. It is a large watershed (1300 km^2) where the precipitation varies largely over the area and no radar precipitation data is available for me. That's why I choose to use precipitation gages. Thank you for the time you give. Farah

Thank you Chris for your reply. Well, yes i defined ModClark grids using WMS 9.1. For the precipitation, I created "Rain Gage" coverage and I computed gage weights in WMS. Then I defined the precipitation using "User gage weighting". When I saved the hms file, a dss file was created by WMS for precipitation. While running the model in HEC-HMS, the error 40024 occured. Is this procedure is suitable to define precipitation grid based on Thiessen Polygon method gage weighting? Is there any other method to define precipitation grid based on gages? Thanks, Farah

Hi. Does anyone have an idea about this HEC-HMS error? "ERROR 40024: Invalid or missing excess precipitation data for grid cell" Thank you in advance. Farah.