HEC-1, Flood Hydrograph Package

All ordinary flood hydrograph computations associated with a single recorded or hypothetical storm can be accomplished with this package. Capabilities include rainfall-snowfall-snowmelt determinations; computations of basin-average precipitation from gages or hypothetical storms; unit hydrographs via direct ordinates or Clark, Snyder or SCS methods, or by kinematic wave transforms; hydrograph routing by level-pool reservoir, average-lag, modified Puls, Muskingum, Muskingum-Cunge, and kinematic wave methods; and complete stream system hydrograph combining and routing. Best-fit unit hydrograph, loss-rate, snowmelt, base freezing temperatures and routing coefficients can flow over and through breached dams. Expected annual flood damage can also be computed for any location in a river basin. Interfaces with HEC-DSS routines for storing, retrieving, graphing, and tabulating data.

A hydrograph-array size of 2,000 ordinates capability is available in this terminal release of HEC-1 version 4.1. The increased array size reduces limitations encountered when simulating long storms using short time intervals. The large-array version also allows greater flexibility in checking for numerical stability of simulation processes (e.g., kinematic runoff and routing computations).

Notes: Support Material: User's Manual CPD-1A, June 1998
	Date of Last Program Release: June 1998