Navegando por Assunto "Rio Uraim - PA"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Análise da susceptibilidade a inundações na bacia hidrográfica do Rio Uraim, Paragominas - PA
(Universidade Federal do Pará, 2017) CORREA, Denison Lima; MATTA, Milton Antônio da Silva; http://lattes.cnpq.br/9053359402276755
The phenomenon of flooding is a natural event, given by the extravasation of water to the greater river bed, a fact caused by intense precipitation causing the amount of water that arrives simultaneously to a point of the river is greater than its capacity of flow. The main objective of this dissertation was to analyze the susceptibility to floods in the Uraim River basin in the municipality of Paragominas state of Pará, based on the physical and morphometric characteristics of the basin and to evaluate the areas most prone to flooding within the urban zone. Geoprocessing techniques were used to extract the basin by SRTM images and to use digital image classification to obtain soil use in the basin and extraction of elevation and slope to compose the map algebra process by the AHP method in order to generate the map susceptibility of the basin and conduct a discussion with the urban area of the municipality of Paragominas. The Uraim River basin It has a drainage network with area and perimeter of 4,981 km² and 202 km, respectively. The basin has a maximum altitude of 255 meters and a minimum of 1 meter in the exudation, the average altitude being 136 meters. The slope of the main watercourse calculated on the basis of the extremes (S1) showed a value of 0.08 m/m expressed a value that overestimates the mean slope of the water course, and hence the peak flood. For the variable use and occupation of the soil present variables where it can be analyzed that the Uraim river basin is in the process of altering its vegetation cover, evidencing a high index in the pasture and agriculture classes, besides the deforestation in Permanent Preservation areas, the areas evidence of high impermeability in the preservation areas. It can be seen that the neighborhoods most susceptible to flooding are in regions near the river basins of the basin: Promissão, Uraim, Cidelândia, Angelim and Cidade Nova. The AHP technique used to determine the weights of classes contributing to flood susceptibility was effective because it reduces and simplifies the proposed problem, which minimizes the errors of judgment during the process.
Acesso aberto (Open Access)
Simulação da resposta hidrológica à mudanças de uso e cobertura da terra em uma bacia hidrográfica no leste da Amazônia
(Universidade Federal do Pará, 2018-10-05) FERREIRA JÚNIOR, Pedro Pereira; SOLER, Luciana de Sousa; SOUSA, Adriano Marlisom Leão de; http://lattes.cnpq.br/4371199443425884
The loss of vegetation in the Amazon has been occurring for some decades and the growth of annual deforestation rates is noticeable. The agricultural expansion is indicated as a new agent in this dynamic by the overthrow of the vegetation for the cattle raising and later implantation of mechanized agriculture. This work explored the potential relationships between hydrological variability and landscape organization in the Uraim River Basin at Northeast of Pará. The possible effects of land use and land cover changes effect on streamflow were investigated from Soil hydrological modeling and Water Assessment Tool (SWAT) combined with the projections of future scenarios generated by the Conversion of Land Use and its Effects at Small Region Extent (CLUE-S), the SWAT efficiency was also evaluated in simulating the monthly streamflow when fed by evapotranspiration (ET) of the Surface Energy Balance Algorithm for Land (SEBAL). The results showed the skill of SEBAL to estimate ET under different land use and land cover identified in the watershed. The algorithm presented overestimations, but good precision with the values measured in the field, having greater accuracy in the dry season and using average eight days MODIS images. The SWAT model streamflow simulations were better when ET estimated by SEBAL were applied, which were confirmed by reduction in absolute and relative errors and by the efficient calibration of the most sensitive parameters. The modeling was considered from good to very good according to the NSE, RSR and PBIAS coefficients found. Almost all the variables used in CLUE-S modeling forced land use and land cover changes, mainly biophysical parameters. The projected scenarios indicate agricultural expansion for the northwestern sector of the watershed and greater concentration in the southwest portion. Agricultural areas will increase its by 93.2 km2, corresponding to 13.4% of watershed until 2034, which indicate to a reduction of 34.4% in the streamflow to dry season and an increase of 38.6% in the rainy season. The results suggest that climate change may have played a more pronounced role in the hydrological pattern than the very land use and land cover change projected by CLUE-S. It is intended, therefore, to provide subsidies for environmental monitoring, informing about necessary interventions, targeting the decision-making regarding the sustainable use of water resources.