Detecção de áreas de risco à desertificação no Estado do Rio de Janeiro com utilização de geotecnologias

Abstract

Desertification is a process linked to the land degradation due to anthropic activities, and natural factors such as climate variability. Desertification affects about two-thirds of the world's countries, and has implications for the economic, social and environmental sectors, as well as diminishing the quality of human life. The State of Rio de Janeiro presents spatial, temporal and climatic variability and economic activities. In this sense, the objective of the present study was to identify areas at risk of desertification in the State of Rio de Janeiro, based on the physical indicators (climate, soil, land use and occupation, vegetation, relief features, conservation units and geomorphology) and the determination of an Index of Sensitive Environmental Areas (ESAI). In order to determine the ESAI, the intermediate indices were calculated: Soil Quality Index (PLQI - geomorphology, soil type and slope), Soil Management Index (MQI - conservation units and land use and occupation), Index of Climate Quality (CQI - rainfall, dryness index and relief orientation). From these intermediate indices, it was possible to obtain the ESAI, for the mesoregions of government and for the municipalities. The ranges of susceptibility adopted were: Low, moderate and high susceptibility calculated for each intermediate index and ESAI. Most of the state has been classified as not susceptible to desertification. The north region had the highest percentage of the low susceptibility class (57.85 %), followed by the northwest (31.96 %), Metropolitan (25.43 %), lowered (10.96 %) and Serrana %). For the moderate class, the northwest region (26.66 %), north (57.85 %), Serrana (2.60 %), Metropolitan region (1.98%) and Coastal shallows (0.60%) had the highest percentage. São João de Meriti, with the highest percentage of areas with low susceptibility (99.36 %) and municipality of Cardoso Moreira with a higher class of moderate susceptibility (48.02 %). The method was efficient in determining areas susceptible to desertification and serves as an alert for the need for mitigation measures or adaptation to environmental degradation processes.