The dynamics of cultivation and floods in arable lands of Central Argentina

摘要

Although floods in watersheds have been associated with land-use changesince ancient times, the dynamics of flooding is still incompletelyunderstood. In this paper we explored the relations between rainfall,groundwater level, and cultivation to explain the dynamics of floods in theextremely flat and valuable arable lands of the Quinto river watershed, incentral Argentina. The analysis involved an area of 12.4 million hectareduring a 26-year period (1978–2003), which comprised two extensive floodingepisodes in 1983–1988 and 1996–2003. Supported by information from surveysas well as field and remote sensing measurements, we explored thecorrelation among precipitation, groundwater levels, flooded area and landuse. Flood extension was associated to the dynamics of groundwater level.While no correlation with rainfall was recorded in lowlands, a significantcorrelation (P<0.01) between groundwater and rainfall in highlands wasfound when estimations comprise a time lag of one year. Correlationsbetween groundwater level and flood extension were positive in all cases,but while highly significant relations (P<0.01) were found in highlands,non significant relations (P