Aportes do escoamento na escala mensal: estação fluviométrica Palmares/PE.

Abstract

Research on river flows throughout the year is of great importance for the supply of demands to water users in a river basin. This work is about flow analysis through the separation of flows in hydrographs (underground and runoff) and determination of base flow index in monthly data in the hydrometric station Palmares, Pernambuco, Brazil for the period from January 1977 to December 2007. The Microsoft EXCEL spreadsheet was used to plot the flow versus time curves and the use of linear functions in the tracing that interconnects the inflections of onset of rise and the period of recession of the hydrograph. For the calculation of flow rates, numerical integration methodology was used in the areas delimited in the hydrograph, resulting in volumes. The use of rain and drought months, as well as the inclusion of El Niño and La Niña events, allowed us to quantify the domain of the base flow in a more detailed way according to differentiated characteristics of seasonality and climatology. The base flow in the El Niño years was 18.21% higher for the dry season and 27.40% for the rainy months, compared to the La Niña years. The methodology of this work contributes to better approaches in the use of water resources management tools in catchment.