WARMF Engineering Module
The engineering module is a dynamic watershed simulation model that calculates daily runoff, ground water flow, hydrology and water quality of river segments and stratified reservoirs. WARMF divides a watershed into land catchments, stream segments, and lake layers. Land catchments are further divided into canopy and soil layers. These watershed compartments are connected to form a network for hydrologic and water quality simulations.
Processes:
The land surface is characterized by its land uses and cover, which may include forested areas, agriculture lands, or urbanized cities. Daily precipitation, which includes rain and snow, is deposited on the land catchments. WARMF performs daily simulations of snow and soil hydrology to calculate surface runoff and groundwater accretion to river segments. The water is then routed from one river segment to the next downstream river segment until it reaches the terminus of the watershed. The associated point and nonpoint loads are also routed through the system. Heat budget and mass balance calculations are performed to calculate the temperature and concentrations of various water quality constituents in each soil layer, river segment, and lake layer.
Algorithms:
The algorithms of WARMF were derived from many well established codes. Sources of these algorithms are as follows:
The Integrated Lake-Watershed Acidification Study Model (ILWAS):
- snow, river and groundwater hydrology
- mass balance for acid base chemistry
Areal Non point Source Watershed Environment Response Simulation model (ANSWERS):
- sediment erosion and deposition
- sediment resuspension and transport
The Water Quality Analysis Simulation Program - 5 (WASP5):
- sediment sorption-desorption of pesticides and phosphorus
- kinetics of nutrients and algal dynamics
Storm Water Management Model (SWMM):
- pollutant accumulation on land surfaces
- pollutant mixing and washoff (modified from original SWMM algorithms
The first order decay of coliform and BOD and its impact on dissolved oxygen follows the traditional water quality models.
Systech Water Resources, Inc. • 1200 Mount Diablo Blvd. • Suite 102 • Walnut Creek, CA 94596 • Phone 925-355-1780