Análise da variabilidade espaço-temporal da umidade do solo na bacia experimental do Riacho Guaraíra - Paraíba

• Autor(a) principal: Lira, Nicholas Borges de
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/9151
• topic: Umidade do solo; Variabilidade espaço-temporal; Bacia experimental; Cobertura vegetal; Resolução temporal; Soil moisture; Spatio-temporal variability; Experimental basin; Vegetation cover; Temporal resolution; ENGENHARIAS::ENGENHARIA CIVIL

This Master thesis studies the spatio-temporal variability of soil moisture in the Guaraíra experimental watershed, located on the southern coast of Paraíba. As it is an experimental basin, it is of great importance to know how its variables work and interact together, in order to allow inferences in similar basins. In that case, the soil moisture play a role responsible for several factors in the watershed, like flow generation, drought development and groundwater recharge, for example. Initially, being a small watershed, (5,84 km²) it was believed that its results related to soil moisture should be very homogeneus, however, a hypothesis was made about how the different soil and vegetation cover between each station could make an influence in the results. The research had as its main objective to study the spatio-temporal variability on the soil moisture on the said study area, in order to use these information as subsidy to similar basins, even bigger ones. For this it was used data from the TDR (Time Domain Reflectometry) soil moisture probes installed at five stations and pluviographs in the study area combined with manual collection for calibration and validation of the probe’s results since april 2013 until September 2014. This way, it was possible to apply the methods used by Vachaud et al. (1985( and Mittelbach & Seneviratne (2012), with the disconnection of the resilts of soil moisture into its variable and invariable parts on time, which consist in the spatio-temporal variability of soil moisture analysis. As the TDR probes used to measure soil moisture give a temporal resolution of one hour, an analysis of temporal resolution was proceeded, allowing to use diary data in order to represent the soil moisture, without significant variation of results. The results confirmed the homogeneity of spatio-temporal variability of the soil moisture in the basin, except for the station with less vegetation cover, where the spatio-temporal variability of soil moisture differed significantly from the rest of the basin. Thus, it was perceived the similiraty between the results of soil moisture in the terms of temporal mean and anomalies, for the stations with similar vegetation cover. This way, it was concluded that the fact that the results of the station with less vegetation cover had been so different is due to its lack of vegetation cover, being very different from the rest of the basin, thus enhancing the importance of vegetacion cover as a natural controller of soil moisture. As to the temporal variability, that is more susceptible to climatic effect, like precipitation for example, while the spatial-variability is more related to the invariable terms on time. Yet, the calibration of the probes was successfully executed and they do represent well the soil moisture for that study area, allowing continuous monitoring on that experimental basin.