Stanford watershed model

HSPF. The Hydrologic Simulation Program (FORTRAN) ( 1, 42) is based on the Stanford Watershed Model. Version 7 of HSPF incorporates the process models of SERATRA in its aquatic section, with several (user-selectable) options for sediment transport computations. HSPF includes the generation of transformation products, each of which is in turn subject to volatilization, phototransformation, biolysis, etc. 

The Stanford Watershed Model (SWM) developed at Stanford University (10- It can simulate the hydrologic behavior of an entire watershed. 

Hydrology Stanford Watershed Model IV. Dept, of Civ. Eng., Stanford Univ., Stanford, Calif. Tech- Rep.39. 1966. 210... 

The weight of soil carried in the surface runoff has been estimated by relating the sediment load to the rate of energy dissipation at the land surface by the rainfall and flowing water. The resistance of the soil to eroding forces has also been considered (4), and a method has been developed to estimate the net effect of erosion on radioaerosol transport. The volume of the liquid phase is estimated on a continuous basis by the Stanford watershed model, through consideration of a water budget. This feature has been retained in the HTM-1. 

One major difficulty in assessing the accuracy of any transport simulation method is the inaccuracy in runoff estimations. The basin selected for the study described was of minimum size for application of the Stanford watershed model. This is reflected in the corresponding uncertainties in all computations. However, it is worth noting that the measured and simulated concentrations of Sr and 137Cs seldom differed by more than a factor of two. This observation suggests that increasing the accuracy of simulated runoff processes will result in an increased accuracy in radioaerosol transport estimates as well. 

The authors acknowledge with appreciation the assistance of N. H. Crawford and R. K. Linsley in the use of the Stanford watershed model computer program. Assistance and data for this study were also provided by the Santa Clara County Flood Control and Water District, the San Jose Water Works, and the U. S. Geological Survey in Menlo Park. 

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