Aplicação de funções lineares na delimitação dos pulsos de vazões na estação fluviométrica engenho Mato Grosso/PE.

Abstract

A separate chapter, in research related to the granting of rights to the use of water resources (one of the instruments of management of Law No. 9.433 / 97), is the definition of criteria for the ecological flow, considering that this component represents the integration of the water resources management with the environmental management in the river quantitative, in order to preserve the riparian aquatic ecosystem. Many methodologies have been developed, from statistical criteria, with single value for every month, to holistic models, which measure habitat levels according to flow changes. An alternative way is to consider different values of the ecological flow according to the natural flow regime, considering the importance of the riparian life according to the variability of the flow in the hydrological year. The present research aims at delimiting flow pulses through linear functions, in a daily historical series, that interconnect inflections of ascension and flow recession. The methodology was applied in the historical series of daily data of the fluviometric station Engenho Mato Grosso/PE/Brazil (Period: 01/01/1997 to 12/31/2006). Flow pulses indexes (IP) were calculated in the daily and monthly scales, quantifying the proportion of the variability of the delimitation in relation to the fluvial flow. The mean IP was 0.1427. The volume of pulses was dominant in 6.57% of the days of the series, with the year 2000 with more expressive values. The mean monthly IP showed that the months of May to July presented the highest values (mean 0.2172), and lower values between the months of September to November (mean 0.0737). The proposed methodology proved to be an important tool in ecological flow studies, contributing to the hydrological vision of the flow regime for the construction of the environmental hydrograph.