The alluvional phenomenon in the high valley of the Río Negro River, Argentina.

Abstract

As human socio-economic activities on the Earth's surface intensify, interferences with nature and its dynamics increase. Examples of this are increasing settlements on river banks and flood plains. In arid and semi-arid regions, convective storms produce flush flooding that causes soil erosion, and sediment transport and deposition. The consequence of this common situation is catastrophic in those basins with many human activities and settlements. In the High Valley of the Rí­o Negro River, in North Patagonia, Argentina, cities expanded without any planning in the last decades. These cities have occupied, in a chaotic way, regions that are unsuitable for permanent human settlements. Thus, flush floods are affecting the urban and social dynamics of these cities. Hence, it is necessary to modify the basin management plan in order to make sustainable development of the basin possible. In order to come up with the appropriate technology for future protection, this paper presents an initial diagnosis of soil degradation by linking a soil erosion model with a rainfall- runoff model using GIS techniques.