WATER RESOURCES MANAGEMENT FOR AN IRRIGATION PROJECT USING A DSS

Abstract

The operation of canal irrigation systems is a complex task with spatially variable soils, crops and weather conditions. The releases for the irrigation, reach the fields through a hierarchical network of main canals, branch canals (secondary canals) and distributaries (tertiary* canals). The proposed study area, Harbhangi irrigation project is constructed to serve two major purposes such as (a) Providing irrigation facility to its own command area and (b) Transferring water from Vansadhara basin (project basin) to adjacent Rushikulya basin which is water scarcity basin through a natural carrier, river Padma . Hence, the accurate estimates of reference crop evapotranspiration(ET0), crop coefficients for the different stages of various crops, crop water requirement (CWR) of the project and preparation of irrigation scheduling for the canal network envisage the optimal use of the storage water of reservoir and also preventing the ayacut area from the negative effects, i.e., leaching, water logging and subsequently ground water pollution. Steps, are taken to calculate daily ET,, by Penman-Monteith method. Crop water requirement of the project with single coefficient method is estimated. Determination of optimal yield from the reservoir with several failure fraction conditions at different annual reliability and indicating dependability of the project to sustain the future food requirement of the project command area is carried out. Also, irrigation scheduling for the different crops of the project is prepared individually and periodical release for all the distributaries of the project for better management of the irrigation system.