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| Author(s): |
Deise Nunes Furlan
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Centro de Energia Nuclear na Agricultura (CENA/STB) |
| Defense date: | 2013-12-11 |
| Examining board members: |
Maria Victoria Ramos Ballester;
Ricardo Guimarães Andrade;
Humberto Ribeiro da Rocha;
Paulo Cesar Sentelhas
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| Advisor: | Maria Victoria Ramos Ballester; Ricardo Guimarães Andrade |
| Abstract | |
The state of Rondônia has undergone significant land use change in the last 30 years due to the occupation and exploitation of natural resources. The changes occurring in the landscape in recent years, mainly due to the replacement of forest areas for grazing, has strong influence on the hydrological cycle and climate. There are many studies that seek to understand the dynamics of climate and biosphere in the Amazon region, however, there are many difficulties for implementing surface measurements and often they are for specific sites and do not represent the whole ecosystem. Thus, an alternative for these studies is the use of satellite data, which allow to obtain information from the surface with reasonable spatialtemporal coverage. Due to the complexity of the Amazon region, the study area, the use satellite images is a possibility for the estimation of the energy fluxes on large scales current research. In this context, the aimed to estimate the energy balance components including daily evapotranspiration through the Surface Energy Balance Algorithm for Land - SEBAL and evaluate how the replacement of forest areas other land use types has influenced the balance water and energy in the central region of the by Rondônia state in the last 25 years of use and occupation of land. The study was carried out with multispectral images (Landsat 5 and 7 Lansat) of the central part of Rondônia (scene 231/68), which is located Urupá River basin including part of the river basin Ji-Paraná, with temporal serie 1987-2011. Thus it was possible to analyze the spatial and temporal patterns of the energy floxes including actual daily evapotranspiration evaluating the SEBAL algorithm accuracy for different classes land use. The results showed that the study area has undergone significant change in vegetation cover, considering that in a period of 25 years the forest area was reduced by 69.1 % of its initial area. The analyzes carried out with the variables estimated by SEBAL in the context of land use change, show that the model is sensitive enough to detect these changes in terms of energy fluxes on the surface. In general, the replacement of forest areas by agriculture and pasture caused an increase in the surface albedo, net radiation reductions, increased surface temperature, increasing heat flux in the soil, increasing the of sensible heat flux, decline of latent heat flux and consequently, reduction in evapotranspiration rate. This shows that the impact on the local climate with the replacement of the forest by other land uses are changing the hydrological regime and the local climate, as the evapotranspiration decreased by 33 % when compared with areas of forest. Considering the extent of the forest area that was reduced during the last years, the impact may be even higher. (AU) | |
| FAPESP's process: | 10/02228-0 - EFFECT OF CHANGE OF USE AND SOIL COVER IN THE WATER AND ENERGY BALANCE OF RIVER BASIN JI-PARANPÁ (RO) MULTITEMPORAL DATA USING REMOTE SENSING |
| Grantee: | Deise Nunes Furlan |
| Support Opportunities: | Scholarships in Brazil - Doctorate |