Socio-Economic Indexes for Water Use in Irrigation in a Representative Basin of the Tropical Semiarid Region

Abstract

Performance evaluation of irrigated agriculture is an important tool that assists in decision-making on water management in the river basin, particularly in tropical semiarid regions. This study was carried out using information from the Jaguaribe River basin, located in the Northeast region of Brazil, which has an important restriction in the availability of water resources and high competition for water use. From a set of indicators (production, water, economic, and social), the overall performance index of irrigated agriculture was estimated (ranging from zero to 1.0) for two scenarios: high water scarcity and low water scarcity. The performance index used was based on the mean value of these security criteria normalized with respect to the maximum value of the indicator for the crop obtained in the sub-basin. A low performance index of irrigated agriculture (less than 0.3) has always been associated with inadequacy of more than one security indicator. Crops with significant cultivated areas and, therefore, requiring a high volume of irrigation, such as rice, sugar cane, banana, and green coconut, require technical interventions related to the management of the soil–water–plant system aiming at improving yield with less water. Under conditions of water restrictions, crops with performance indexes higher than 0.3 should be prioritized. The study presented here for Jaguaribe River basin may support public policies related to irrigation and agronomic techniques necessary to improve the performance of agricultural under tropical dry lands.