HYDROLOGICAL RESPONSE TO CLIMATE CHANGE CONDITIONS IN THE PIANCÓ CATCHMENT
Hydrological modeling, Climate Change, SWAT, Semiarid, Water Resources
Climate change has increasingly been present in several sectors of society, especially the water sector. As water resources gain more emphasis due to the increasing demand for water use, it becomes crucial to understand the effect of climate change on the components of the hydrological cycle at the basin scale for the development of hydroclimatic adaptation in water resources management. Thus, the objective of this work is to evaluate the pattern of the hydrological response in the Piancó catchment in a near future (2021-2040). This is a subbasin of the Piancó-Piranhas-Açu river basin, completely inserted in the Brazilian semi-arid, whose springs are in the state of Paraíba. The hydrological response will be evaluated from simulations with the distributed hydrological model Soil and Water Assessment Tool (SWAT). The hydrological simulations will be performed for three hydroclimatic conditions: 1st – for the present climate (1982-2005), and 2st and 3st – for the climate in the near future (2021-2040) in two scenarios of Representative Concentration Pathway (RCP): 4.5 and 8.5. The data used to perform the hydrological simulations for the present climate will be of the Executive Agency of Management of Waters of the State of Paraíba (AESA) and of a database of surface stations, regularly arranged in the space with a resolution of ~ 25 km. The data of the climate projections used for hydrological simulations for the future climate will be of the Coupled Model Intercomparison Project Phase 5 (CMIP5), regionalized for a resolution of ~ 25 km for precipitation and temperature. The SWAT performance will be conducted using hydrographs, permanence curve, dispersion chart and statistical indices widely applied in hydrological studies. The initial stages of the research have already been developed, such as: the evaluation of observed hydroclimatology and the hydrological modeling, more specifically the geoprocessing phase for the delimitation of catchment and the drainage network, as well as the SWAT implementation of the soil classes found in the basin and its types of land cover, according to the classes found in the model. The initial results indicate that the hydrological year of the basin begins in January, with April being the month that the peak of flow occurs (~ 50 m³.s-1), whereas the months of Jul-Dec the streamflow is intermittent (~ null). With respect to the physical characteristics of the catchment, obtained in the geoprocessing phase, these indicate that the dominant soils and vegetation cover in the basin, respectively, are the neosols (57% of the area) and the caatinga (79% of the area), which was represented in the SWAT as a deciduous forest. With the development of the research, it´s expected to analyze the impacts in the basin scale on the hydrological processes and water availability in a condition of climatic change in the semiarid of Brazil