Variabilidade da ocorrência de deslizamentos de terra e sua relação com a precipitação na cidade de Manaus
Since the creation of the Manaus Free Trade Zone, the Amazonian capital experienced a strong population growth due to the exodus caused by the generation of commercial and agrarian activities, having in the urban territory taken account of outlying areas, without basic infrastructure. The city is...
| Autor principal: | Barbosa, Rafael Gomes |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/12625 http://lattes.cnpq.br/7340357278408576 |
| Resumo: |
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Since the creation of the Manaus Free Trade Zone, the Amazonian capital experienced
a strong population growth due to the exodus caused by the generation of commercial
and agrarian activities, having in the urban territory taken account of outlying areas,
without basic infrastructure. The city is characterized as a flat region sectioned by
watercourses (igarapés) with the topographical level increasing according to the
distance of the Negro River in the same manner as the slope. In this way, the
association of the physical characteristics of the land with the social ones formed zones
of risk with 23 thousand residences (Civil Defense of Amazonas, 2013) subject to
phenomena such as landslides, a problem aggravated by the marked local
precipitation regime. To explore the occurrence of these natural disasters and its
relationship with rains, were used records of landslides of Manaus Civil Defense,
between 2010 and 2015, along with precipitation records from a network of automatic
weather stations and Weather Radar precipitation estimates, in addition to satellite
imagery, radio sounding data, NCEP Reanalysis and synoptic analysis. The analysis
indicated a strong relation between the variables, with the seasonality of occurrences
following the precipitation – greater (smaller) number of landslides occurring
predominantly in the wettest months (dry). Were found in the north and east zones
suffering the hardest hit, and the south central and midwest were the ones which
presented less records of landslides. Considering accumulated precipitation between
24 and 96 h preceding the records made by the Civil Defense, smaller values of
precipitation were observed related to landslides in the northern and eastern areas,
and the other areas had highest precipitation values for triggering these disasters. The
case studies revealed the landslides occurring due to cumulative precipitation on
consecutive days (gradual saturation of the soil) and to more intense precipitation
events in a single day. In front of the results, it is observed that the landslides are not
spatially distributed in the city being the northern and eastern areas most affected due
to geographical characteristics associated with precipitation. Still, it is necessary to use
a longer period and different data sources to elucidate specific amounts of precipitation
capable of generating natural phenomena in question. |