Floods in La Plata. Its analysis in relationship to rainfall over the last decades of the 20th century

Abstract

Over the last two decades of the 20th Century, important floods in Del Plata Basin have been caused by the global climate change. Greater La Plata (comprising La Plata City and the towns of Berisso and Ensenada ) is not exempt from this problem and that is the reason for our research. The report is based on La Plata (Buenos Aires province, Argentina) rainfall temporal distribution over the last two decades and current times. Floods at Greater La Plata are the result of the confluence of three factors: precipitation (mainly when high rain falls), groundwater tables whose upward pressure has increased due to their elevation) and the south east wind (which makes the river rise). The study was carried out taking into consideration daily rainfall data from La Plata Aero Meteorological Station (National Meteorological Service) and flood data obtained from the local newspaper El Dí­a. The variability in rainfall temporal distribution studied on a monthly and yearly scale showed changes in quantity and intensity caused by the rainfall increase in the Pampas Grasslands over the last decades and, in turn, demonstrated this is a fact that should be considered seriously for future constructions projects in the city and management of extreme hydrologic events such as floods. The results of this report have revealed that the floods along the 1970s amounted to 25 whereas that number rose to 78 in the 1990s ( last decade herein considered).