HEC-2 is a steady flow hydraulics model that was the predecessor to HEC-RAS. Thousands of hydraulic studies were done with HEC-2 in the 70's, 80's, and 90's. Before importing HEC-2 data,...

United States Army

The first HEC-2 Water Surface Profiles program was released in 1969. The capabilities of HEC-2, and other HEC programs, have evolved; primarily driven by project and application...

2025年2月10日 · The U.S. Army Corps of Engineers (USACE) Hydrologic Engineering Center's River Analysis System (HEC-RAS) computer program supersedes its HEC-2 computer program, which was widely used in the preparation of studies and restudies for the National Flood Insurance Program (NFIP).

computer programs HEC-1 Flood Hydrograph Package and HEC-2 Water Surface Profiles can be used to model the flood-wave movement through a river. By analyzing the existing conditions and the

The program computes water surface profiles for one-dimensional steady, gradually varied flow in rivers of any cross section. Flow may be subcritical or supercritical. Various routines are available for modifying input cross-section data, for example, for locating encroachments or inserting a trapezoidal excavation on cross sections.

The most common methodology used to calculate flood elevations for a stream is a step-backwater computer program, such as HEC-2 or HEC-RAS. For more complex flooding situations, a computer program that models two-dimensional flow may be used. HEC indicates the model was developed by the US Army Corps of Engineers Hydrologic Engineering Center ...

2005年11月5日 · HEC-2, named HEC-RAS, (River Analysis System) was released by the Corps in 1995. The later versions of HEC-RAS have the added capability to solve time dependent flows (unsteady). There are computational differences between HEC-2 and HEC-RAS so that they compute slightly different water surface elevations for the same input data.

These files contain data for the HEC-2 and HEC-RAS hydraulic models developed by the US Army Corps of Engineers Hydrologic Engineering Center. The data were used to calculate water surface elevations in the creeks for previous flood insurance studies in Santa Clara County.

The HEC-2 special bridge routines use a trapezoidal approximation for low flow calculations (Yarnell equation and class B flow check with the momentum equation). The HEC-RAS program uses the...