Estimation of Evapotranspiration and Water Productivity

Evapotranspiration from the earth’s surface is an important component that affects regional water resources and irrigation practices. Particularly in paddy fields, it is important to estimate the rate of evapotranspiration to make decision on proper water management and irrigation schedules. Remote sensing is used to manage irrigated command area extensively as it gives information on land use, irrigated area, crop type, crop yield, etc., both spatially and temporally. The derived information from remote sensing will be analyzed using geographic information system (GIS). Hence the objective of present study was to estimate the evapotranspiration using ArcSWAT and CROPWAT model in Bhadra command area and also, water productivity of the irrigated area.A GIS interface ArcSWAT and CROPWAT models were applied to part of Bhadra command area located between Shimoga and Davanagere district, Karnataka State, India. Evapotranspiration, irrigation water requirement, crop water requirement and water productivity were calculated using ArcSWAT and CROPWAT softwares.