Mudanças no uso do solo e comportamento das vazões na bacia do Paranaíba - Brasil

Abstract

Soil use and occupation tend to have a significant influence on water resources, and may change the quality and availability of water. The objective of this study was to analyze the influence of land use and land use change on flow behavior in the Paranaíba River basin - Brazil. He chose to work with the Paranaíba River basin, as it stands out as the second largest unit in the Paraná Hydrographic Region and totals a drainage area of 222.6 thousand km². With regard to its location in the central region of Brazil, it occupies around 2.6% of the national territory, besides including the states of Goiás with 63.3%, Mato Grosso do Sul with 3.4% and Minas Gerais 31, 7%, in addition to the Federal District with 1.6%, totaling 197 municipalities, in addition to the Federal District. In relation to the proposal of analysis of land use change and occupation, the mappings for the periods of 1985, 2003 and 2013 were elaborated, following the following divisions of classes of use and occupation of the soils, being they, Bodies of Water, Urban Influence, Mineral Influence, Forestry, Pasture, Natural Vegetation and Agriculture, where it can be seen the expansion of some categorized classes. Precipitation data for the period from 1975 to 2013 totaling a historical and / or temporal series of 38 years were tabulated and the results referring to the precipitations evaluated in the 21 pluviometric stations analyzed allowed us to understand that the overall mean was equal to 1,466.7 mm, in addition to pointing out the years with the highest annual precipitation index and the lowest annual precipitation index. In relation to the rainfall seasons, the highest annual average is the EP21 Sacramento with 1659.02 mm and with a lower annual average EP14 Buriti Alegre with 1,309.18 mm. In relation to the tabulation of the fluviometric data, 23 stations were used and the historical and / or temporal series adopted for the pluviometric data were also maintained, in which the statistical tests of Mann-Kendall and Wald-Wolfowitz the runs were applied. Tendencies in the maximum, medium and minimum flow regimes, in order to do so, it was observed that there is a higher occurrence of trend-setting scenarios for the maximum flow regimes that presented a higher reference to the TNSQ non-significant fall tendency indicator, although 23 records were found for The flow regimes when they were analyzed for the general period of the sample being from 1975 to 2013, there was greater representativeness when there was the fragmentation in sub periods being these 1975 to 1985, 1985 to 2003 and 2003 to 2013, thus, it was possible to verify that The analysis for larger time periods has hidden tendential scenarios. Using the Wald- Wolfowitz test as a tool to verify the consistency of the Mann-Kendall test, it is confirmed that the Mann-Kendall test has greater expressiveness to be used in detecting scenarios trends in flow regimes. The analysis between the rainfall and flow data allowed to estimate the flow data for the fluviometric stations and then the calculation of the anthropic transformation index for the entire Paranaíba River Basin - Brazil.