Uso do modelo SWAT para avaliar os impactos das mudanças climáticas nos recursos hídricos da bacia hidrográfica do rio Una - PE.

Abstract

The Una River basin has been suffering in recent years with recurrent occurrences of environmental disasters. The large spatial and temporal variability of extreme weather systems favors such occurrences. Several climate models with projections of temperature and precipitation show the Northeast of Brazil as one of the regions that will be most affected by climate change. In this context, hydrological simulations due to climate change are of great relevance. The present study evaluated the impact of climate change on the surface water resources of the Una river basin. For this it used the distributed hydrologic model SWAT, to model the processes that involve the soil water balance and the drainage network flow. The analysis was performed in three steps. In the first step, the hydrological model was calibrated and validated with observational data. In the second stage, flow scenarios were simulated, using as input to the hydrological model the climate scenarios generated by the ETA climate model for the period 2020 to 2047. In the third stage, the behavior of the flow scenarios in different points of the basin was analyzed through the interpretation of the permanence curve and the average flow. Therefore, in the first stage the hydrological model satisfactorily represented the seasonal variability of the flow, but with reduced values. On the other hand, in the flow scenarios no similarity with the seasonal flow variability was observed, but there was a reduction in the average flow values and the maximum flow rates. This same reduction was observed in the permanence curves for the 10%, 50% and 90% percentiles. In any case, it is concluded that due to the reduction of precipitation observed in the climate scenarios and the ability of the SWAT hydrological model to simulate the seasonal variability of the flow, it is necessary and possible the water management and the planning of mitigating measures of the possible impacts. in the Una river basin.