Proposta de mapeamento de cobertura e uso da terra a partir do método de detalhamento progressivo : estudo de caso para o entorno dos reservatórios das UHEs Batalha e Itumbiara

Abstract

Mapping of land cover and use is essential to understanding the form of appropriation, alteration and dynamics of geographic space. In this context, attention is drawn to the hydrographic basins located next to the reservoirs of Hydroelectric Power Plants (UHEs), which present intrinsic changes in the coverage and use of the land due to the implementation of such projects. Thus, the main scope of this work is to provide a methodological proposal for mapping the land cover and use, with progressive detailing and for the context of the surroundings of reservoirs of Hydroelectric Power Plants (UHEs), having as a case study the UHEs Batalha and Itumbiara. The approach to mapping land cover and land use with progressive detailing consisted of three successive and complementary stages, which attend to different scales, spatial and temporal cuts and data. In a simplified way, the proposal of progressive detailing was based on: a first stage, recognition (1:100,000), in which cartographic and secondary census data were used for the period from 1985 to 2020, contemplating the Areas of Direct Influence (AID ) of the HPP Batalha and Itumbiara; a second stage, semi-detail (1:25,000), with the use of Sentinel 2 images from the year 2021, spectral indexes and incorporation of manually vectorized files, for the spatial clipping of the Direct Contribution Basin Boundaries (LBCD) and; a third and final step, detail (1:10,000), which used merged CBERS 4A images to achieve a spatial resolution of 2 m and for the Immediate Border Limit (LBI) of the reservoirs. The data from the reconnaissance stage showed a clear dynamics of land cover and use between 1985 and 2020 in the context of the IDA of the HPP of Batalha, while in the case of the IDA of the HPP of Itumbiara, land use has already been consolidated in the same period. In the semi-detail stage, the LBCD of the Batalha HPP was mainly related to agricultural use and, secondly, to the covering of savanna vegetation, while in Itumbiara the prevalence of land management by pasture is evident. The last step, in detail, portrayed a condition of greater protection of the edges of both areas under study by vegetation cover, which can be explained by the proximity to the reservoirs of the two hydroelectric projects. The adequacy of the proposal is highlighted, as it provides historical, updated, detailed and consistent information about the occupation condition of the surroundings of hydroelectric power plant reservoirs, which can be applied to other projects and spatial contexts.