Vulnerabilidade de reservatórios superficiais às mudanças climáticas: o caso de rios com deflúvios anuais de alta variabilidade

Abstract

The global climatic changes and its effects have brought great worry in the last decades, to the scientific community, from the stakeholders and society in general. Although it´s predictable, in global scale, the possible consequences of the climatic changes – for example, the elevation of the sea levels and change of pattern of the precipitations – there´s great difficulty in quantify in local scale, these impacts. More vulnerable regions, like the Brazilian semiarid, have been shown even more weakened when gone through climatic adversities. Considering the relevance of the studies that evaluate the impacts of these prospective climatic changes, this study evaluates the influence of the change of patterns of precipitation and the evaporation of the reservoir yield. It was evaluated the conjunct relation of the evaporation and precipitation, through the net blade, in the water balance of the reservoir, simulated on monthly level, with removals happening simultaneously. The study concluded that the rivers which presents high variability (CV between 1,2 and 1,6) that are characterized by the semiarid regions, are more sensible to any changes which comes to occur on precipitation or evaporation of this region. Once the great majority of the rivers from the semiarid northwest present coefficient of variation of the annual runoff between 1,2 and 1,6 and, basically the water availability of the region depends of superficial reservoirs, the management of these reservoirs should be done carefully, since they are very sensible to these climatic variation.