Banca de DEFESA: SAMARA FERNANDA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : SAMARA FERNANDA DA SILVA
DATE: 03/08/2023
TIME: 08:30
LOCAL: Pós-Graduação Engenharia Civil
TITLE:

Land Use And Cover of the Soil and Precipitation in the Values of the Rio Grande Basi Basin - BA

 

 

KEY WORDS:

CHIRPS, LUCC, analysis of hydrological series, SWAT

PAGES: 169
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The Rio Grande basin (BHRG) is an important tributary of the São Francisco river, it is part of one of the most active agricultural frontiers in the world and has been undergoing changes in land use and land cover (LUCC). Additionally, the decade from 2010 to 2020 was marked by a reduction in rainfall, which contributed to an almost exponential increase in irrigated agriculture. Such factors culminated in the increase of land and water tenure conflicts. Thus, understanding the hydrological processes becomes crucial for the management of the basin's waters. Thus, this research aimed to evaluate the effects/impacts of changes in land cover use and precipitation on the components of the water balance of the Rio Grande basin, in particular on the flow regime. The two variables – precipitation and the LUCC – were then initially studied separately and, subsequently, hydrological modeling was carried out and, finally, simulations were carried out to evaluate separately and separately the effects of the two variables on surface runoff. Due to the low density of the rainfall network, it chose to use the rainfall estimated by the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) product, which required validation using the “point-to-pixel” technique. Eleven rainfall stations were used and then compared with those estimated by CHIRPS, on a monthly basis using the period 1981 to 2020. CHIPRS was accurate in detecting rainfall, satisfactory in the probability of detecting these events and exhibited good ability to represent spatial variation. precipitation time. The LUCC analysis was carried out using landscape ecology metrics (from 1990 to 2020) and correlations of areas of use classes with flows near the basin outlet. Significant reductions in the areas of the classes were observed, especially of native vegetation (reductions) and anthropized areas (increase). There was a trend of reductions in average, minimum and maximum flows and strong significant correlations between average and minimum flows with the increase in areas of rainfed agriculture, irrigated agriculture, pasture and urban infrastructure. In the hydrological modeling, the Soil and Water Assessment Tool (SWAT) model was used, which was fed with CHIRPS estimates, calibrated and validated for three different periods (LUCC 1990 and climatological data from 1981 to 1995; LUCC 2010 and climatological data from 1996 to 2010; LUCC 2015 and climatological data from 2011 to 2020) using the multi-site-sequential calibration technique. After this stage, using the 'one factor at a time' technique, experiments were simulated – LUCC combination arrangement and precipitation series estimated by CHIRPS. The results show that the SWAT performed satisfactorily in its analysis in the three periods studied on a monthly scale, especially in the headwaters sub-basins. The model well represented the progressive decline of flows in all fluviometric stations. Precipitation was the most sensitive variable in the generation of runoff, however as precipitation is reduced, the sensitivity of runoff from BHGR to LUCC increases.

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COMMITTEE MEMBERS:
Externa à Instituição - ANDREA SOUSA FONTES - UFBA
Presidente - 1688881 - ALFREDO RIBEIRO NETO
Externa à Instituição - CAROLYNE WANESSA LINS DE ANDRADE - UFPB
Externa ao Programa - 1510820 - JOSICLEDA DOMICIANO GALVINCIO - nullExterno à Instituição - RICHARDE MARQUES DA SILVA - UFPB