Causes and consequences of the hydro risk in a sector of the “pampeana” plain, Argentina

GENTILI, JORGE O; CAMPO, ALICIA M.; UBOLDI, JULIO; GIL, VERÓNICA

Bonn

Otro; 7th International Science Conferene on the Human Dimensions of Global Environmental Change; 2009

IHDP

The study is located in the pampeana plain, the most important region in our country due to its population and food production, in the Argentine Republic. The area includes the basins of the Sierras Australes system in the province of Buenos Aires, that flow into the lacunaria system Encadenadas del Oeste. The environmental elements inherent to its location present a high vulnerability to different threatening, among which overflowings and floods are outstanding.The aim of this study is to analyze the relationship between the happening of the overflowings and floods and the interannual variation of the rainfall that feature the region. The environmental characteristics that help the happening of these events have been analyzed starting from statistic records, topographic charts, satellite images and works in field. The images correspond to dry and wet periods on different dates in October and November 1999, 2001 and 2002.At very high precipitations, water behavior is variable. High gradients in the source of the rivers make quick lowering possible, and provoke floods. The low morphologic energy of the low basin contributes to the overflowing of large sectors, where railway and road infrastructure and inappropriate macro-hydro buildings make water draining difficult. Economic loss is generated, human lives become under risk and the permanence of the infrastructure become lower making human security vulnerable. The knowledge o the climatic and hydro geomorphologic dynamics of the sector contribute to the management of resources and of the risk.