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Effect of reducing variability in reservoir water levels on irrigation returns and stream flow minimums: An application of discrete stochastic programming and safety first programming
Abstract
Conflicts arise in the management of multi-purpose reservoirs between several objectives: (a) flood control, (b) recreational benefits from relatively stable reservoir levels, (c) irrigation, and (d) levels of remaining stream flows. In the last case, pressure exists to maintain relatively constant remaining stream flow levels for environmental purposes, recreation, wildlife, and the assurance of the delivery of contracted water to downstream users. This research focuses on the impact of providing reduced variability in remaining stream flows on irrigation benefits as well as increased variability in reservoir water levels in a southern Nebraska setting. The estimated impacts are developed using a discrete stochastic programming model which also includes flood control constraints. In this analysis, an integer safety-first risk model is imbedded in a discrete stochastic programming model to derive optimal release strategies and initial and conditional cropping decisions. The safety-first model is used to insure minimum stream flows while releasing impounded water to maximize irrigated crop returns. The model employed three irrigation release decisions with crop choice and irrigation strategies dependent upon risk of water availability and a conditional derived optimizing irrigation decision set. The erosion/productivity impact calculator (EPIC) model is used in this study to simulate necessary yield and irrigation data for the crops. Forty-seven years of actual incoming stream flow and precipitation data provide the stream flow probability levels utilized in the model. Variability in remaining stream flows is controlled by moving upper and lower remaining stream flow levels of the model closer together. Historical stream flow variability provides a useful contrast in which to view the changes in remaining stream flow levels. The results show relatively modest decreases in irrigation benefits from reducing variability in remaining stream flows. Also, the impacts on reservoir levels variabilities are relatively modest attesting to the efficiency of the water allocation model.
Subject Area
Agricultural economics|Civil engineering|Hydrology
Recommended Citation
Javed, Muhammad Tariq, "Effect of reducing variability in reservoir water levels on irrigation returns and stream flow minimums: An application of discrete stochastic programming and safety first programming" (1995). ETD collection for University of Nebraska-Lincoln. AAI9611055.
https://digitalcommons.unl.edu/dissertations/AAI9611055