# Author: Krest Engineers

## Introduction to Dam Breach Modeling using HEC-RAS

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…

## Modeling Reservoir and Dam in 2D HEC-RAS by Storage Area and SA/2D Connection

Instead of being modeled in 1D HEC-RAS by storage area and inline structure, reservoir and dam can also be modeled in 2D HEC-RAS by storage area + SA/2D connection +…

## Modeling Reservoir and Dam in 1D HEC-RAS by Storage Area and Inline Structure

A reservoir is usually built to provide flood control, water supply and irrigation, recreation, or their combinations by blocking a river via embankment dams (Figure 1). A reservoir may have…

## Applying Alternating Block Method to Create “Nested” Storm Distributions

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.…

## 2019 Regional PMP Study for LA, MS, OK and AR and Its Application in HEC-HMS

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…

## GIS Shapefile, Microstation DGN File, and Combined Scale Factor

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…

## Grid Coordinate, Ground Coordinate, Distance, Combined Scale Factor

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…

## Use HEC-GridUtil to View and Process Gridded Data Stored in DSS files (2 of 2)

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…

## Use HEC-GridUtil to View and Process Gridded Data Stored in DSS files (1 of 2)

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…