Integrated management of groundwater and surface water under climate change scenarios

ABSTRACT This study aimed to simulate the joint use of surface water and groundwater in the urban-rural basins of the municipality of São Carlos and evaluated the impact of climate change scenarios in the system. A calibrated WEAP model is employed with 5 km resolution climate model data from the CPTEC - PROJETA project with the future scenario of RCP85 and RCP45 from 2007 to 2050. This system is utilized to create various future scenarios of groundwater and surface-water abstraction of public water supply, industrial and private demands, with combination of conjunctive use 50-50% of both type of resources and 100% from one them. Results were assessed by analyzing the flow duration curves and the level of the aquifer for the 2007-2050 period. The simulated climatic scenarios indicate that the pressure over groundwater in the area could represent a challenge due to the progressive depletion of the resources affecting the system sustainability, the flow of the main rivers with the 95% percentile presents a reduction of 20% in some cases. This modelling approach can be used in other river basins to manage scenarios of supply and demand.