GIS-remote sensing-based village-level hydrological balance approach for agricultural water planning

Ensuring food security through the increase in food production can be realised by converting agricultural fallow lands into cultivable ones and assuring irrigations in three crop seasons in all agricultural lands. That can be done through a village (i.e., mouza) level water management planning through rainwater harvesting. This needs step by step procedures based on hydrologic balance for providing the best way of management of water resources to secure precious agricultural lands from man-made degradation. This study was conducted at a mouza Gohalura in the Red and Laterite Zone of West Bengal, India. In that village major crops grown were ‘Aman’ rice (A practices of Rice cultivation by transplanting in rainy season and harvested in early winter season) during the rainy (i.e., monsoon) season; Groundnut during Rabi under both rainfed and irrigated farming situations and ‘Boro’ rice (a practice of rice cultivation by transplanting in late winter and harvesting in early summer) in summer. The major problems in crop production in that village were some rainfed agricultural lands with erratic and uncertain rainfall of which about 26 percent (i.e., 464 mm) received during non-monsoon period (15 October to 7 June), and a high infiltration rate of soil. Shortfall in annual water balance of 248.13 mm could be managed through existing river lift irrigation from the adjoining river Dulung, a tributary of the Subarnarekha River. Application of GIS and remote sensing were useful in land use land cover classification, creation of a digital elevation model of the village and calculation of areas under individual classes of land. Creating and renovating water harvesting ponds in the mouza would facilitate multipurpose benefits for the farming community including agriculture in three crop seasons in all cultivable lands through such rational water management planning in that village. Following such village-wise water balance approach another 16.37 ha (i.e., agricultural fallow out of the total agricultural land area of 40.23 ha) i.e., about 69 per cent increase in irrigated area could be made possible. Such methodologies could be projected for other areas, and that could be followed in other areas also.