A influência de parâmetros morfométricos e de aspectos da paisagem sobre a configuração de hábitats físicos de riachos no bioma no Cerrado

Abstract

Recent investigations indicate that the morphometric parameters of watersheds and drainage network, based on the knowledge of geomorphology, are important in the configuration of physical habitats of streams. Despite this, research that seeks to understand the configuration of the physical habitats of streams to the detriment of landscape conditioning explores more environmental and anthropic factors, such as land use and cover, than geomorphological aspects. In this sense, there is a frontier of knowledge about the physical habitats of streams, and this frontier is even greater in the Brazilian context. Thus, three questions guided this dissertation: 1) Do the morphometric parameters influence the configuration of the physical habitats of streams in the Cerrado? 2) Is it possible to say that the morphometric parameters have more importance than other geophysical factors and that anthropogenic disturbances on the physical habitats of streams? 3) Do morphometric parameters and landscape aspects influence the configuration of physical stream habitats differently, in a general perspective and by hydrological units? Therefore, the main objective was to analyze the influence of morphometric parameters and other aspects of the landscape, at the catchment scale, on the configuration of physical habitats of streams of streams in different hydrological units in the Cerrado biome. The methodology consisted of six main steps: i) selection of the Digital Elevation Model; ii) vectorization of hydrographic basins and the drainage network of streams in Geographic Information Systems; iii) measurement of morphometric parameters; iv) acquisition and preparation of landscape features; v) selection of physical stream habitats; vi) and data analysis and modeling. Generalized linear regression models were constructed in the last methodological step, both general models with all 199 streams and specific models for the five hydrological units. The results showed that the morphometric parameters were important influencers of the configuration of the physical habitats of streams in the Cerrado (Question 1). Both morphometric parameters and landforms were the most important explanatory variables for the physical habitats of streams (Question 2), confirming the importance of geomorphological knowledge of watersheds in the configuration of physical stream habitats. And although the general models have some similarities with the models by hydrological units, the particularities of each region were significant and should be considered in the management of the quality of water courses in the Cerrado biome (Question 3). The present dissertation showed that for future research and management of water resources in streams in the Cerrado, such as water modeling, monitoring of the lotic ecosystem, among others, the geomorphological information of the watershed is relevant and should be considered. In addition, it is pointed out that the results are unprecedented and can help managers of water resources in the Cerrado in relation to the health of water courses and the provision of ecosystem services. The results also showed that the use of geotechnologies based on geographic information systems and remote sensing are relevant to understand the configuration of the physical habitats of streams in the Cerrado, enabling a more agile and less costly monitoring.