Uncertainties in Water Scarcity Index due to water use and climate changes: Case of two Legal Amazon watersheds

Abstract

Water scarcity is a major global problem with the potential to impact socioeconomic development and the environment. Currently, mitigating issues related to the lack of water has become an aim for the public and private sectors. Water scarcity can be estimated by the ratio between water use (withdrawal or consumption) and water availability (a minimum discharge), named Water Stress Index (WSI). But some uncertainties can influence the perception of water scarcity, such as population growth, land cover, climate changes, uncontrolled water use, and the scale at which the WSI is evaluated. To improve the knowledge about water management in two basins in eastern Legal Amazon, We estimated WSI at unit-catchments scale from MGB hydrologic model, water use data, and climate change projections. Our results showed a safe water situation in most parts of the basins, but first-order unit-catchments need more attention due to high WSI values being able to compromise downstream water use.