A GIS-based spatially distributed crop water demand modelling for Pullambadi canal command area in lower Cauvery basin, Tamil Nadu, India

摘要

Water shortage is an actual warning to food production for people in semi-arid areas. Due to overuse, it is necessary to describe appropriate approaches, plans, and management for irrigated land. Pullambadi command area faces water crisis throughout the year, due to over-exploitation of water in irrigation for both Ariyalur and Tiruchirappalli district. Due to improper utilization of water, it is necessary to find proper crop evaporation (ETc) and crop coefficient (K-c) for proper management of water resources. The crop water estimation for the years 2015 and 2016 was computed for the Pullambadi canal in this study adopting remote sensing and geographical information system (GIS) approach to identify the crop water demand and crop water supply using crop coefficient. Banana, sugarcane, and paddy crops were identified with the assistance of Landsat-8 satellite images as well as Google Earth. Hargreaves method was adopted for the valuation of reference evapotranspiration. ET(c)and water requirement of different crops were spatially analysed, and it was high in the western region and less in the eastern part. It was found that sugarcane crop requires more water than other crops. A simplified water balance approach was opted to estimate the water demand requirement supply. The requirement of water supply for all crops was high during July-October season. Incorporation of these findings in irrigation scheduling and planning could improve the management and, largely, demonstrate the water resources in the study area. Remote sensing and GIS approach in irrigation water scheduling are helpful due to fast quantification than tradition methods.