DYNAMICS OF GROUNDWATER UTILIZATION AND IRRIGATED CROPPING PATTERNS IN TAMIL NADU: AN ECONOMIC PERSPECTIVE

Abstract

Groundwater has become the most important source of irrigation in India fulfilling 62 per cent of the total irrigation area. Tamil Nadu's hydrology is unique in nature with the presence of two monsoons with little perennial river systems, which has gradually evolved into an irrigation system that is mostly dependent on borewells. The study analyses the trends in the use of groundwater and irrigated cropping patterns in Tamil Nadu during 2010 23. The information on secondary data (ground water depth) was taken from Central Ground Water Board (CGWB) Ground Water Year Books, and cropped area, production and yield data was taken from Directorate of Economics and Statistics (DES), Government of Tamil Nadu for 32 districts. Groundwater level data during pre monsoon and post-monsoon period (2010-2023) has been analysed with data on irrigated areas for five crops like paddy, sugarcane, banana, coconut and groundnut. Temporal trend analysis was performed as total change (ΔGW) and average annual rate of change; comparative structural analysis of irrigated cropping pattern was undertaken as base triennium (2010–12) versus recent triennium (2021–23) comparison and a crop–groundwater linkage analysis was carried out by categorising districts based on whether they are depleting or improving. Groundwater level decreased by 1.47 m during pre-monsoon and 1.65 m during post-monsoon in the state, which shows net groundwater recovery. Of the 32 districts, 24 have shown improvement, and 8 have shown depletion. The total area of irrigated paddy, coconut, banana has increased and a sharp decrease in the area of sugarcane by 58.7 per cent. The CAGR of Tubewell irrigation was 3.59 per cent per annum. Based on the study, a set of recommendations are forwarded for the district to consider for crop water planning, promotion of micro-irrigation, realignment of agricultural support policies, and enhancing the governance of groundwater.