EVALUATING CLIMATE CHANGE ADAPTION MEASURES FOR AGRICULTURAL WATER PRODUCTIVITY : A CASE STUDY OF INDO GANGETIC PLAINS, INDIA

Abstract

The global freshwater resource is under pressure due to population growth and climate change, particularly in the agricultural sector of water-stressed countries. India exemplifies this challenge, with limited per capita freshwater availability and agriculture consuming a significant portion of the country's water resources. India's population is projected to surpass China's by 2024, with an expected growth rate of 7 to 8 percent in the next decade. Urbanization is also rising, with an estimated 600 million people in urban areas by 2030. These factors will strain water resources for food production, urban development, and industrial activities. An OECD study identifies India’s northwestern region as one of the top three water risk hotspots for agriculture. Thus, optimizing water productivity is crucial for sustainable agricultural growth in India, where water scarcity is a more significant constraint than land. Cultivating water-intensive crops like paddy and sugarcane, mainly in water-scarce regions, limits water availability for other essential crops. This situation is exacerbated by different factors, including imbalanced incentives and subsidies for rice and sugarcane, leading to a mismatch between cropping patterns and water availability (Sharma et al., 2018). Promoting agricultural growth should focus on more than just improving productivity per unit of land but also on enhancing productivity per unit of water, particularly in the case of irrigation water. This research contributes to that goal (Sharma et al., 2018). We have conducted a comparative analysis of the blue water productivity of three primary water intensive crops, rice, wheat, and sugarcane, under present and projected conditions considering climate change scenarios. A comprehensive framework was established to evaluate the efficiency of adaptation strategies in enhancing water productivity (WP) while considering the impact of climate change. The adaptation measures comprise optimizing cropping patterns (OCP) and upgrading irrigation techniques (UIT), which involves shifting from less efficient surface irrigation to spray and drip irrigation. The water footprint theory was applied to estimate the spatial allocation of blue water footprints to determine water productivity. A nonlinear optimization model was employed to identify the most suitable cropping patterns to maximize the system's overall water productivity. The findings indicated that more than just relying on optimal cropping patterns is needed to counteract the detrimental effects of climate change on WP. Nonetheless, implementing upgraded irrigation techniques alone or in conjunction with optimal cropping patterns was able to mitigate the negative impact of climate change on WP in the context of SSP2-4.5 entirely. In the most favorable scenario (which involves implementing a combination of optimal cropping patterns and drip irrigation), there would be a reduction of 0.48% (equivalent to 88,943 hectares) and 0.04% (equivalent to 7,213.63 hectares) in the planting areas of rice and wheat, respectively. In contrast, there would be an overall expansion of 2.22% (equal to 59,023.63 hectares) in the planting area for sugarcane. Variations in the optimal cropping patterns can be attributed to adjusting decision variables (crop planting areas) to improve the objective function (i.e., WP). Implementing this scenario could result in an overall decrease of 1.7% in total production. Furthermore, this strategy could help to alleviate the blue water loss by 19.07 billion cubic meters. Food security is not compromised in this optimal scenario, as the study area still has a 67.13% export of total production. However, this export is decreased by 8.8% (75.92-67.13) from the current situation, mainly due to a 28.82% increase in population, causing a 34.21% increase in crop demand. The outcomes of this research can be utilized by policymakers in the agricultural industry to modify irrigation techniques and cropping patterns in reaction to the changing climate conditions of the Indo-Gangetic Plain of India.