Environmental vulnerability to linear erosive processes in the south-central sector of the municipality of Mirante do Paranapanema - SP

Author(s)

Mariana Lopes Nishizima

• Document type: Master's Dissertation
• Press: Presidente Prudente. 2021-05-28.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências e Tecnologia. Presidente Prudente
• Defense date: 2021-03-26
• Advisor: João Osvaldo Rodrigues Nunes

Abstract

The social and economic changes caused in urban and rural environments have acquired the greatest repercussions due to the accelerated changes in landscapes. In this sense, the relief stands out for being the surface that makes life possible, allowing the interaction between the dynamics of nature and society. In it, the morphodynamic and morphogenetic processes occur, responsible for the formation of the relief. Currently, the dynamics of society are visible, interpenetrate and/or stand out from the dynamics of nature. Such environmental issues assume importance in several fields of knowledge, especially in geographic science. In this respect, the work has as main objective to understand the morphodynamics of the relief; related to the characteristics that determine and influence the environmental vulnerability index to linear erosive processes in part of the municipality of Mirante do Paranapanema - SP, since it does not cover the entire municipal boundary and encompasses part of the neighboring municipalities, therefore it concerns the most center-south of the municipality in question, we emphasize here that environmental vulnerability refers to linear erosive processes, so, furrows, ravines, and gullies. For the elaboration of cartographic documents, it was necessary to use geotechnologies, Geographic Information Systems - SIG, satellite images, and software such as Arc Gis 10.6.1, Quantum Gis 2.16, IBGE geographic data information (shapes), satellite images: ALOS / PRISM; SRTM; Sentinel; and Landsat 8, for the Water Balance the Excel software, and the use of the Hierarchical Analytical Process Technique - AHP for the elaboration of the final maps of Environmental Vulnerability to the Linear Erosive Process. The interrelationships of natural elements: geomorphology, terrain curvature, slope, simplified soil sketch, surface temperature, and vegetation index (NDVI); as well as the social aspects: land occupation and its use, crossed among themselves, and through certain weights defined based on bibliographic references and fieldwork, from the technical perspective of the geographers involved in the present dissertation, made it possible to elaborate maps of environmental vulnerability to linear erosive processes, from March to June 2016, concerns periods of higher humidity (rainy) and dry (drought) on the surface of the studied area. Such results helped, as tools for the spatialization of geomorphological phenomena, in the deepening of studies on the theme of erosion in the region of Pontal do Paranapanema - SP. Finally, it was observed that the different levels of environmental vulnerability to linear erosive processes, in climatic conditions: dry and/or humid, are directly related to land uses, interconnected to the types of relief, soils, vegetation cover, and dynamics of historical occupation by social groups/individuals. In this regard, it was possible to notice that there is a difference in intensity in the environmental vulnerability to linear erosive processes in two periods of the year. In the summer season, in March, it presented the greatest presence of the moderately stable class, mainly in areas with small rural producers, such as in the settlements located in broad hill reliefs with flat tops and extensive and straight slopes with Oxisols. In the winter season, in June, there are an increase of medium, moderately vulnerable, and vulnerable classes, especially in areas where sugarcane is planted. The same level of high vulnerability occurs in the northern sector with exposed and shallow soils, wavy hilltops, concave and sloping slopes. (AU)

• FAPESP's process: 18/08293-0 - Environmental vulnerability to linear erosive processes in the south-central sector of the municipality of Mirante do Paranapanema - SP
• Grantee: Mariana Lopes Nishizima
• Support Opportunities: Scholarships in Brazil - Master