Impacto de mudanças do uso de solo sobre a hidrologia numa planície de inundação amazônica, caso de estudo: o lago Janauacá
The Janauacá floodplain, located in the central Amazon region (Brazil, AM) and on the left bank of the Solimões river, is a representative system of flood plains in the Amazon region. In the present study, based on in situ data and remote sensing data, it was sought to analyze the temporal dynamics...
| Autor principal: | Conchy, Tainá Sampaio Xavier |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/12620 http://lattes.cnpq.br/8236360646545600 |
| Resumo: |
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The Janauacá floodplain, located in the central Amazon region (Brazil, AM) and on the left bank of the Solimões river, is a representative system of flood plains in the Amazon region. In the present study, based on in situ data and remote sensing data, it was sought to analyze the temporal dynamics of land use (1972-2016) and its impact on the hydrology of the basin. For this, 5 maps of land use were generated. In sequence, these 5 maps and 2 additional (representing deforested and forested areas) were used as input of a hydrological model (LUMP - FP) that generated 7 simulations (from September 2006 to December 2015) where the same meteorological conditions were maintained. The 5 maps of land use showed high overall accuracy (Kappa index> 0,8). The temporal analysis of the use of the soil emphasized a decrease of the areas of solid forest for an increase of the anthropic classes (pasture and swidden) and of altered vegetation (secondary vegetation). With regard to hydrological modeling, after validation in terms of water level and discharge (NSE> 0,95 for both), the model LUMP - FP was judged as capable of modeling the lake. The analysis of the impact of soil use on hydrology was carried out using three hydrological indicators. The estimates of run-off and rainfall ratios ranged from 0.48 to 0.56, and the estimates of evaporation ranged from 0,348 to 0,350 km³.year-. The model emphasized that these two parameters appeared to be sensitive to seasonality, but there is no significant difference when coverage is changed. However, it has been noted that deforestation leads to a slight decline in the ratio of run-off to rainfall. Refining the analysis, through a temporal analysis of these contributions, it was observed that: i) land changes affected the water balance more strongly in the dry years (and little in the flood years) and during the first part of the hydrological cycle (November to July); ii) changes in land use affected mainly the segment of run-off and river water contributions, and in the dry season, the water table actively contributes to the closure of the hydrological balance. |