Opportunity-driven hydrological model development in US Army research and development programs

Abstract

AbstractThe US Army has compelling needs for making hydrological forecasts. These range from tactical predictions of water levels and soil moisture, to strategic protection of both Army and civilian assets and environmental resources. This paper discusses the history of hydrological model development by the US Army Corps of Engineers (USACE) as influenced by changes in needs and technologies. It concludes with a description of the Gridded Surface/Subsurface Hydrologic Analysis (GSSHA™) model, a two-dimensional, structured-grid, physics-based hydrological, hydrodynamic, sediment and nutrient/contaminant transport model, developed over the past two decades, that is currently used by the USACE. The surface hydrology of the USA has been divided by the US Geological Survey into 21 major geographic domains that contain either the drainage area of a major river or the combined drainage areas of a series of rivers of similar character developed in one geographic province. Eighteen of the regions occupy the land area of the conterminous USA. Alaska, the Hawaiian Islands and Puerto Rico are separate domains. This approach provides a framework for the hydrological modelling discussed in this paper for sites within six of these regions. That the physics-based GSSHA modelling capability has so far been applied with success gives confidence in its more widespread application.