Study of flow in the river basin Itapemirim
Name: NATÁLIA GOMES DE SOUZA MENDES
Publication date: 29/02/2016
Advisor:
Name |
Role |
|---|---|
| ROBERTO AVELINO CECÍLIO | Advisor * |
| SIDNEY SARA ZANETTI | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| ALEXANDRE CÂNDIDO XAVIER | External Examiner * |
| GIOVANNI DE OLIVEIRA GARCIA | External Alternate * |
| JOSÉ EDUARDO MACEDO PEZZOPANE | Internal Examiner * |
| ROBERTO AVELINO CECÍLIO | Advisor * |
| SIDNEY SARA ZANETTI | Co advisor * |
Summary: MENDES, Natalia Gomes de Souza. Study of flow in the river basin Itapemirim. 2016. Dissertation (Master of Forest Science) - Federal University of Espírito Santo, Jerônimo Monteiro, ES. Adviser: Prof. Dr. Roberto Avelino Cecílio. Co-advisor: Prof. Dr. Sidney Sara Zanetti.
Flow studies are of great importance for the understanding of water availability of a region. Among the potential causes that alter flow regimes in river basins are the variability of rainfall and changes in land use. In this context, the present study aimed to analyze the behavior of the flow of water courses of the catchment area of the river Itapemirim (BHRI) and relate them to changes in forest cover and rainfall. Were determined for 11 of sub-basins, the minimum flow of seven days duration (Q7), the average annual flow (Qmed) and the annual maximum flow rate (Qmax). By the estimate of the average monthly rainfall for BHRI by Inverse interpolation Distance Weighted Squared (IPD2), we calculated the maximum monthly rainfall (Pmax), monthly minimum (Pmin) and the annual total (Pa) and the precipitation of rainer quarter (Ptc), the driest quarter (Pts), rainier semester (Psc) and driest semester (Pss). The mapping of forest cover of native forest was obtained using the classification technique by Maximum Likelihood of Landsat 5 images. For the analysis of the relationship between rainfall and flow rates in the period 1985-2011, at intervals of two years, and for the year 2014, associations were created by regression analysis, and applied the F test at 5% probability. For quantitative analysis of the association between the forests cover percentage, the annual precipitation and the regime of flow in the period 1985-2011 (1987, 1991, 1995, 1999, 2003, 2007 and 2011). It was performed by adjustment of multiple linear regression equations, and applied the Student t test with 5% probability. In addition, the partial correlation analysis was used to verify the effect of forest on the variation of the flow in order to fix the effect of annual precipitation and used the F test at 5% probability. The total rainfall exerted a strong influence on the flow of the studied sub-basins. It has been found that were annual rainfall (Pa) that explained considerably variations in Qmed, rains of the rainy season (Pmax and Psc) for Qmax, and the rains related to the maximum events (Pa, Psc and Ptc) which probably kept the minimum flow of the rivers during periods of drought (Q7). Thus, it was evident the influence of the climate control of the rains on the regime of flow in the BHRI sub-basins during the analysis period. It was found that the reduction of forest caused increases in Qmed Rive sub-basins and Usina São Miguel. Increased forest influenced the increase of the Q7 in Usina Paineiras sub-basin in a very expressive way. The study identified significant associations between forest and flows in some of BHRI sub-basins, especially those of large areas.
Keywords: River flow (Statistical Methods), forest cover, rainfall, remote sensing.
