Indicadores de vazões mínimas de referência em sub bacias do Rio Miranda

Abstract

Due to population and economic growth, Mato Grosso do Sul is undergoing an expansion of its agricultural frontier. This is placing a burden on the water resources, that allied to drought, can lead to environmental degradation. One requirement to permit continuity in water use is the maintenance of minimum flow for aquatic ecosystem support, also termed the residual, reminiscent, ecological or environmental flow. The main aim of the present study was to apply the methods used to establish this minimum flow, defined by numeric values representing the volume of water that must remain in the river. The proposed methodology to determine the indices and indicators of the minimum reference flows was preliminarily applied to a section of the River Aquidauana, and, thereafter, repeated for a section of the River Miranda, for purposes of comparision. Observed fluvial data was subjected to consistency analysis, and statistical tools used to obtain the indices and indicators values. A verification test was performed at a station inside the study area, using the avaliable data, interpolating with the proportions of the areas and the percentile relative errors determined. The obtained results accurately represent the temporal flow variation and demonstrate the importance of the method to determining the minimum required flow in places lacking measurements.