A methodology to assess stock pond performance using a coupled stochastic and deterministic computer model

Abstract

A computer simulation model is presented for evaluating the performance of small earthen reservoirs in natural watersheds. The model can be used as a tool in design and impact studies utilizing a minimum of data for calibration. Data from the Beaver Creek Experimental Watershed of Arizona were used to develop the model. Stochastic precipitation and temperature models are used to generate a synthetic time stream of precipitation (rain, snow or a mixture). Deterministic models are used to melt snow, determine runoff volume and route runoff water through the pond. Two seasonal watershed runoff models were developed utilizing the SCS equation with improved accuracy. Output from the simulation model consists of statistics and cumulative density functions for annual spillage, annual retention, and the number of days a pond is dry on an annual and monthly basis. The simulation model yields output that can readily be utilized by downstream water users or ranchers for decision making.