A DEM, before it can be used for watershed delineation, often needs to be reconditioned and pre-processed by “filling” any depressions or sinks (an area lower than its surroundings) to…
A DEM, before it can be used for watershed delineation, often needs to be reconditioned and pre-processed by “filling” any depressions or sinks (an area lower than its surroundings) to…
A storm water pump station (Figure 1) is needed in low areas of a drainage system where drainage by gravity is not possible, such as a depressed roadway segment. Pump…
In hydrologic modeling, "nested" storm distributions are widely used such as SCS Type I, IA, II, III, or the frequency storm in HEC-HMS. One of the advantages of a "nested"…
The SCS Curve Number (CN) is used to quantify infiltration loss during runoff calculation. As illustrated in Figure 1, a curve number should be determined by soil (Hydrologic Soil Groups, or…
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…
Historical hourly or daily precipitation data in gridded format can be imported into a HEC DSS file used by HEC-HMS as time series gridded dataset or gridsets. The commonly available…
NOAA Atlas 14 provides the latest official U.S. precipitation frequency (PF) estimates for various durations and frequencies with lower and upper bounds of the 90% confidence interval. Refer to Post…
Two calibration methods are available in HEC-HMS: semi-automatic calibration using computation points and automatic calibration using optimization trial runs. This post is to focus on calibration by optimization trial runs.…
Two calibration methods are available in HEC-HMS: semi-automatic calibration using computation points and automatic calibration using optimization trial runs. This post is to focus on computation point calibration. Calibration by…