An Integrated Framework for Optimal Allocation of Land and Water Resources in an Agricultural Dominant Basin

The water deficit is one of the primary challenges faced by developing countries, stemming from several factors such as limited water resources, population growth, and climate change. Optimal allocation of water resources represents a comprehensive strategy for water resource management, acknowledging the intricate connections between water systems and their repercussions on the environment, society, and economy. It serves as a means of integrating diverse elements of development plans into a cohesive approach for land and water planning and management. In the current study, we undertook the optimal allocation of land and water resources across different sectors for the water years 2016-17, 2017-18, and 2018-19. The study area chosen was the Munneru basin, situated in the lower section of the Krishna River Basin in India. This basin is predominantly agricultural, covering 63.17% of the area, and was selected to validate the proposed framework concept. Within the study area, we identified six distinct water-demanding sectors and calculated their sectoral water demands at a basin level. To assess water availability in the basin, we conducted hydrological modeling employing the Soil and Water Assessment Tool (SWAT). Furthermore, we determined the crop water requirements for various crops using CROPWAT. For the optimal allocation of water resources, we applied the Non-dominated Sorting Genetic Algorithm-II (NSGA – II) optimization model, considering two different objectives that account for social and economic aspects. To identify superior solutions from the Pareto front, we employed the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Compromising Programming (CP) methods. Through this methodology, we achieved maximum utilization of water and land resources and maximized returns from the agricultural sector. Following the optimal allocation of land and water, we observed an average annual increase of 3.61% in agricultural sector returns. These outcomes demonstrated a substantial enhancement in the water use efficiency across all pertinent water use sectors. As a result, decision-makers may contemplate the implementation of this framework in large-scale regions, with potential expansion to encompass a national sustainable development strategy at the country level.