Bridge scour analysis is often required to design a new bridge or evaluate an existing bridge. Bridge scour depth is a critical bridge design component for foundation calculation. The scouring…
Bridge scour analysis is often required to design a new bridge or evaluate an existing bridge. Bridge scour depth is a critical bridge design component for foundation calculation. The scouring…
A simple hydrograph development technique, developed by H. Rooney Malcom in 1980, is often used to design detention facilities serving relatively small watersheds (less than 640 acre or 1.0 sq…
Disclaimer: This post is a simple introduction to dam breach modeling using HEC-RAS. A H&H modeler should not perform a dam breach modeling task without consulting experienced H&H and geotechnical…
A “nested” design storm distribution, such as SCS Type Type I, IA, II, and III, or the frequency storm in HEC-HMS, is an artificial rainfall distribution using precipitation depth-duration-frequency data.…
Historically Probable maximum precipitation (PMP) rainfall depths for spillway design were estimated using NOAA procedure and methodology such as HMR 51 and HMR 52. However, since HMR 51 and HMR…
Combined scale factor (CSF) is introduced in this post as well as the difference between ground coordinates (surface coordinates) and grid coordinates. As explained in the post, in a GIS…
The earth surface is irregular and curvy. To describe the earth surface mathematically, an ellipsoid is defined to approximate the bumpy earth surface, or more accurately a datum based on…
HEC-GridUtil is tool developed by USACE Hydrologic Engineering Center to manage and view gridded data stored in DSS files. The Post 1 of 2 here demonstrates on how to start…
Gridded data, either a static single grid or time series grids/grid set, can be imported and stored in HEC-DSS files using Vortex or HMS Gridded data importer. HEC-DSSVue is a…
A storm sewer network discharges to a receiving waterbody through the outfall pipe and the receiving waterbody can be a river, channel, lake, ocean, or another storm sewer network (Figure…