Modelo para a Quantificação da Disponibilidade Hídrica: Parte 1 ? Obtenção da Equação de Recessão

Hydrologic modeling is a t ool used to better under- stand and represent the hydrologic behavior of a hydro- graphic basin as the use of hydrologic model shows great potential to characterize the water availability under cli- mate or land use condition changes. The objective of the present work was to develop a model to estimate the mini- mum streamflow of the Paracatu river and its tributaries based on precipitation data. For this study data from 21 stream and 30 rain gages were analyzed. The development of the model to estimate the minimum streamflow from precipitation data was base d on the baseflow recession curve, identifying the parameters that define the 21 stream gages, and these were the recession coefficient of the baseflow ( α ) and the groundwater flow into the main channel at the beginning of the recession (Q0). The results obtained al- lowed to conclude that: the total precipitation in the months that preceded the Q0 occurrence allowed a good estimation of the behavior of this groundwater flow; and the greatest deviations obtained for the values of α occurred in the stream gages located in headwater regions where the topo- graphic, climatic and land use conditions tend to show greater discrepancies in relation to the average conditions of the basin