Análisis comparativo del comportamiento de la escorrentía de tres microcuencas andinas con diferente régimen de precipitación y cobertura vegetal

Abstract

The paper presents a descriptive comparative analysis of the precipitation and runoff of three Andean small watersheds (varying in size between 0.6 and 1 km2), using approximately 8 years of rainfall and discharge data, with the objective to relate differences in runoff behavior to the level of annual precipitation, the monthly distribution of rainfall and land use. The catchment covered with native forest receives on average the largest amount of rainfall (1,540 mm/year), whereas the two other catchments, respectively under grassland with extensive cattle breeding and pine trees, receive annually on average respectively 1,267 and 1,181 mm. Although the analysis did not permit to describe in detail the processes controlling the transformation of precipitation into runoff, the exhaustive breakdown of the daily rainfall and runoff data enabled to define the effect of climate and land cover on the runoff pattern of each of the studied micro-catchments. Furthermore, the detailed analysis allowed to accurately identify the type of events whereby the studied micro-catchments show a different response in runoff related to a difference in climate and land use, which would not have been possible to define using only the average monthly precipitation and runoff data of the catchments, a traditional approach in hydrologic consulting services.