Ecology, Environment and Conservation Paper

Vol 27, Issue 2, 2021; Page No.(650-655)

BEST COMPROMISED RESERVOIR OPERATING POLICY UNDER UNCERTAIN INFLOWS BY FUZZY LINEAR PROGRAMMING

Leela Krishna Karnatapu and Srinivasa Prasad Annavarapu

Abstract

The operation of the reservoir is a complex phenomenon, in which the operator should take suitable decisions to release water for various users to satisfy their objectives. This is further complicated if uncertainties are involved in the parameters of the reservoir operation process. In order to obtain the compromised optimal solution addressing the uncertainties involved in the parameters of the system, Fuzzy optimization approach is very useful. Compromised solution is obtained by Fuzzy Linear Programming (FLP) model considering inflows are in fuzzy. Firstly, the crisp solution is obtained by linear programming by solving the objective function considering for each set of uncertain inflows and corresponding best and worst values of objective are determined. Then objective function and reservoir inflows are fuzzified by considering linear membership function. Finally best compromised policy is found by maximizing the level of satisfaction () considering the modified fuzzy objective and fuzzy inflows by FLP. The above model is applied to Nagarjuna Sagar reservoir on Krishna River located at border of Andhra Pradesh and Telangana state, India. The objective function considered in the present study is maximization of total irrigation releases subjected to irrigation releases, power releases, storage bounds and continuity constraints. The 75% and 80% dependable inflows are considered in the present study for determining the compromised reservoir operating policy. The maximum level of satisfaction obtained by simultaneously optimizing the fuzzified objective function and inflows is 0.5 and best compromised monthly operating policy is presented.