An analysis of the human activities impact on water quantity in the Jequitinhonha Valley, MG/Brazil

Abstract

PurposeThe purpose of this paper is to analyze the changes of the characteristics of the study area caused by human influence and the reduction of flow rates with time, in Água Limpa stream basin, Jequitinhonha Valley of Minas Gerais, Brazil.Design/methodology/approachThe study area is a typical arid zone in the northeast of Minas Gerais, Brazil. Field observations, collection and analyses of precipitation, evaporation, temperature and flow rate data were the main approaches used in this study. The data cover the last 50 years, including aerial photographs and satellite images of different dates. The stream flow rate has decreased in the region of the Jequitinhonha valley in the last decades, in particular during draught periods (base flows), with serious social‐economic and environmental consequences. The increase in stream intermittence is responsible for rural exodus to other parts of the country, mainly to São Paulo state. The study presented provides decision makers with important information that can assist them in making objective decisions relational this problem.FindingsThe research shows that the forest cover has declined, the agricultural and pasture cover have decreased and the deforestation areas have grown. These changes resulted in a spatially diverse landscape with implications in the flow rate, and consequently, in the social‐economic condition of the region considering the high rate of emigration.Practical implicationsThe expected results of this study will be of great importance, because the clarification of the factors addressed in this project will allow progress in the understanding of the reduction of flow rates. This reduction has been occurring in the Jequitinhonha Valley and also in almost all Brazilian rivers.Originality/valueThis paper is original and reports the main causes for decreasing of the stream flow rate in the region of the Jequitinhonha valley in Brazil.