Função geoambiental de depressões doliniformes na planície do araguaia

Abstract

The geoenvironmental analysis constitutes a multidisciplinary tool capable of evaluating in an integrated way the socio-environmental dynamics based on the geological, geomorphological and pedological processes, based on this assumption this work had as main objectives to characterize the geoenvironmental function of the doliniform depressions located in the Araguaia Plain , in the central region of Brazil, four stages were structured for this purpose, the first stage consisting of a bibliographical review containing the theoretical foundation of the possible karst characteristics of these features; in the second stage, the terminologies used in the naming of these doliniform structures were identified, through linguistic methods such as the application of the toponymic lexicographic form and network analysis to evaluate the relationship of the use of terminologies in different academic studies. In the third stage, the mapping and analysis of the morphometry and distribution of the depressions was carried out through the photointerpretation of images from the Sentinel 2A satellite superimposed on digital elevation models of 30 meters of resolution; and in the last stage, the geoenvironmental function of the doliniform depressions in the context of the landscape was analyzed by superimposing thematic maps and applying a geospatial model of environmental susceptibility. The results obtained through a toponymic lexicographical form identified a close semantic relationship between the typologies ipuca, impuca and dolina associated with flooded depressions covered by vegetation, as their meanings emphasize the idea of water as a strong shaping element of the terrain. On the other hand, the application of ipuca terminologies represented a high frequency in works of an interdisciplinary nature, while the concept of ipuca was widely observed in floristic (disciplinary) studies. Through mapping and morphometric analysis, it was possible to identify 24,023 doliniform features in an area of occurrence of 114,900 km², of which most of these formations are located in the municipalities of Cocalinho – MT, Luciara – MT, Ribeirão Cascalheira – MT, Lagoa da Confusion – TO and Pium – TO, having its origin possibly associated with the dissolution of a limestone layer underlying the sedimentary layer of the banana plantation, due to its predominantly circular shapes and predominant alignments in the NE direction, indicating a possible structural control over these features. The analysis of the geoenvironmental function obtained by the susceptibility model showed that ecotonal regions with high density of features are located in highly susceptible areas due to the increase in denudation processes resulting from deforestation and high water intake in the region.