Adaptative success and perceptions on the hydrological disturbances by riverine populations in Brazilian semi-arid streams

Abstract

Brazilian semi-arid streams are characterized by extreme hydrological events, with short periods of fl ooding and long periods of no surface water fl ow. Human populations living in the surroundings of these systems must be adapted to such hydrological disturbances. This paper evaluates the perceptions of riverine human populations in the Brazilian semi-arid, in relation to the hydrological disturbances, adaptations of such populations to withstand drought while maintaining social structure, and their utilization of the watershed during times of fl ooding. Data presented was collected from three riverine human populations that live near intermittent streams in the semi-arid region of Brazil. These populations rely mostly on the intermittent water supply from these systems and on the production from small-scaled agriculture and livestock. The surveyed populations maintain the stability of their social structures and organizations by producing an identifi cation process through representations of hydrological disturbances (fl oods and drought). The resistance and resilience to these events basically involve strategies to avoid social ruptures, through the practice of subsistence agriculture, and the search for opportunities (e.g. adequate sites) to build weirs, wells and �cacimbas� (water holes). A simple yet well-structured scheme to utilize the watershed was found to be important during wet periods. The history of human adaptation to the Brazilian semi-arid depends on the confi gurations that both ecosystem and the social system take at each hydrological cycle. These aspects should be taken into account by decision-makers, and should be included in development-oriented policies adopted for the region. Any attempt to manage the semi-arid ecosystems should include the utilization of hydrological disturbances as part of the human element and its dimensions.