Assessment of Crop Water Demand and Irrigation Water Supply in a Run-off-the-river Based Canal System

Abstract

Proper assessment of irrigation water need for a canal command is required for long term planning and management of water resources. The present study was carried out in the Phulnakhara distributary command of the Puri main canal system distributed in Cuttack and Khurda districts of Odisha. During Kharif season, the Phulnakhara distributary command receives more than the required amount of irrigation water. However, during Rabi season, the canal does not flow at its full supply level as a result of which the total irrigation demand of the canal command area is not met leading to lower cropping intensity and poor crop productivity. The year-wise highest irrigation water demand in Kharif season was found to be 48646195 m3 during 2015-16 and the lowest was 22291100 m3 in 2017-18. Whereas the highest Kharif irrigation supply at the head regulator was 43402176 m3 during 2015-16 and the lowest was 29831328 m3 during 2013-14. The highest Rabi irrigation water demand was found to be 21700766 m3 during 2008-09 and the lowest was 9570257 m3 in 2017-18. Whereas the highest Rabi irrigation supply at head regulator was 26379648 m3 during 2008-09 and the lowest was 615168 m3 during 2009-10. As evident, there is a mismatch between the supply and demand in both the seasons and it is more prominent in the Rabi season. In order to bridge this gap, conjunctive use of canal water with groundwater is found to be a promising solution.