Assessment of climate variability and land use effect on shallow lakes in temperate plains of Argentina.

Abstract

Areal variation in lakes is closely associated with other factors such as intensity of land use of the hydrological basins, climatology, geomorphology and depth. The main objective of this study is to assess the relationship between climatic variability events (El Niño Southern Oscillation, ENSO), land use and shallow lakes' areal variations in the temperate plains of Argentina for the period 2002-2011. The standard precipitation evaporation index (SPEI) was employed in this study in conjunction with the oceanic Niño index (ONI) and in situ annual precipitation data to determine wet, dry and normal years. Shallow lakes' areal variation was analyzed by satellite imagery (MODIS) processing and the variability of the land use intensity was determined based on agricultural estimations. Frequency in the maximum of shallow lake areas was relatively more dependent on any changes in the rainfall regime (ENSO events) than in the land use (decrease/increase of the cultivated area). The El Niño (2002/3) and La Niña (2007/8) events clearly affected the precipitations of the total studied lake regions, with maximum areas in 2002 and minimum in 2008. The results obtained may be an important contribution to mitigate flooding and droughts in the studied area.