Bases para gestão dos recursos hídricos: estudo de processos hidrológicos na bacia do rio Tapacurá

Abstract

The State of Pernambucohas several watershed, where we can to highlight the Tapacurá basin, which includes seven municipal districts and it is responsible for part of the provisioning of the Metropolitan Area of Recife. Due to its importance, several studies about to water resources have been accomplished, however, until the present moment, any study was not accomplished about interception loss, which is a hydrological process of great importance for the water resources managements, it reduces the amount of water that arrives to the soil, it modifies the rainfall erosive capacity, could still condition the swinging of energy of the vegetation, besides giving origin to the alteration of the water quality. This work treats of the study of the loss for interception in different vegetation types (coffee, lemon and vegetation of natural forest) found in the basin of Tapacurá, through his/her determination in field experiment and of the evaluation of prediction models, detaching the analytical model of Gash, in the culture of the coffee. For determination of the loss for interception, they were installed, in the three vegetation types, pluviômetros to measure the total precipitation, interceptômetros to measure the precipitation interns and systems to collect the rain water that drains for the trunk. Close to the coffee plantation, a meteorological station was installed for measurement of the necessary variables to the application of the model of Gash. Different loss taxes were observed by interception in the three studied vegetations. Rains of smaller magnitude presented larger relative losses for interception. The loss for interception was also larger in the rainy period than in the less rainy period. The lineal model in function just of the total precipitation, in a general way, it didn't produce good estimates of the loss for interception, being the best result obtained in the natural vegetation, whose deviation was of -21%. THE analytical model of revised Gash if it showed a good tool to esteem the loss for interception and it presented better result than the original version and the lineal model, with normalized medium deviation of 9% and efficiency of the modelling of 88%. the application of that model is of great importance, because, it produces estimates of processes hidrológicos that, together with other actions, they aid in the administration of the resources hídricos.