Yield Estimation Model and Water Productivity of Wheat Crop (Triticum aestivum) in an Irrigation Command Using Remote Sensing and GIS

Crop yield estimation has an important role on economy development and its accuracy and speed influence yield price and helps in deciding the excess or deficit production conditions. The water productivity evaluates the irrigation command through water use efficiency (WUE). Remote sensing (RS) and geographical information system (GIS) techniques were used for crop yield and water productivity estimation of wheat crop (Triticum aestivum) grown in Tarafeni South Main Canal (TSMC) irrigation command of West Bengal State in India. One IRS P6 image and four wide field sensor (WiFS) images for different months of winter season were used to determine the Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) for area under wheat crop. The temporally and spatially distributed spectral growth profile and AREASUM of NDVI (A(NDVI)) and SAVI (A(SAVI)) with time after sowing of wheat crop were developed and correlated with actual crop yield of wheat (Y-act). The developed relationships between A(SAVI) and Y-act resulted high correlation in comparison to that of A(NDVI). Using the developed model the RS based wheat yield (Y-RS) predicted from A(SAVI) varied on entire TSMC irrigation command from 22.67 to 33.13 q ha(-1) respectively, which gave an average yield of 26.50 q ha(-1). The RS generated yield based water use efficiency (WUEYRS) for water supplied from canal of TSMC irrigation command was found to be 6.69 kg ha(-1) mm(-1).