Estimación de Erosión Hidrica de Suelos para plan de Manejo del Campo Forestal Aguas Frías, Patagonia Argentina

AbstractIn Argentine Patagonia there exist large extensions of lands degraded by overgrazing, this favours soil water erosion. Two million hectares are eligible for forestation (Gallo et al. 2005), with some environmental limitations that require previous studies to prepare development and sustainability proposals. The study area is located in the right margin of the Litrán River, 25 kms of its estuary in Aluminé Lake (Province of Neuquén). In this area, some Mapuche (araucanian) communities carry out stock breeding (mainly goats) using a migrating system. This region presents very severe Aeolian and hydrological erosion.The objective of the afforestation management plan of this land, is the design of control measures, to stop erosion, like perimeter close, afforestation and structural measures for controlling erosional gully. It is then necessary, to characterize the actual and potential erosion, that would allow to carry out with measures monitoring to implement controls and mitigation.Paper presents, pedology map by interpreting and georreferencing satellite images by a Geographical Information System. (GIS).The mapping methodology was based in Hierarchical Classification of Landforms, which is the structure of the geopedology focus for mapping soil (Zinck, 1989). The classification of actual erosion was obtained from the method of the Bureau of Land Management (USDI) by visual inspection of seven aspects of erosion in surface. The estimation of the potential erosion of the floors of the forest field was carried out utilizing the Universal Soil Lost Equation (USLE) and ArcGis 9,2 (ESRI, 2006) to carry out the spatial analysis, obtaining a map of annual soil loss ( tn/has/year) with a spatial resolution of 30 m.The application of spatial analysis tools in the study of soil water erosion in Patagonia, Argentina contributes to the objective of defining define a program of development and adequate management, as a function of the state and degree of potential soil erosion.En la Patagonia Argentina existen grandes extensiones de tierras degradadas por sobrepastoreo lo cual favorece la erosión hídrica de los suelos. De éstas existen más de dos millones de hectáreas aptas para la forestación (Gallo et al. 2005), pero con limitaciones ambientales que requieren estudios tendientes a elaborar propuestas de desarrollo y sostenibilidad.El área en estudio situada en la margen derecha del Río Litrán, a 25 km de su desembocadura al Lago Aluminé de la Provincia de Neuquén, es utilizada por comunidades mapuche para realizar su actividad agropecuaria de producción caprina bajo un sistema trashumante y presenta erosión hídrica y eólica muy severa.Unos de los objetivos del plan de manejo del campo forestal es diseñar un conjunto de medidas de control de la erosión que incluyen cierre perimetral, forestación y medidas estructurales para el control de cárcavas.Resulta así necesario, caracterizar la erosión actual y la potencial, que además permitirá realizar el seguimiento de las medidas de control y mitigación a implementar.Con estos fines, para el campo forestal en estudio, se confeccionó un mapa geoedafológico a partir de la fotointerpretación y posterior georeferenciación utilizando un Sistema de Información Geográfica (SIG). La metodología de mapeo de suelos se basa en la Clasificación Jerárquica de Geoformas, que es la estructura del Enfoque Geoedafológico para el mapeo de suelos (Zinck, 1989). La clasificación de la erosión actual se realizó por el método del Bureau of Land Management (USDI) mediante inspección visual en el terreno de siete aspectos de erosión en superficie. La estimación de la erosión potencial de los suelos del campo forestal se realizó utilizando la Ecuación Universal de Perdida de Suelos (USLE) y ArcGis 9.2 (ESRI, 2006) para realizar el análisis espacial, obteniendo un mapa de pérdida anual de suelos en tn/ha/año con una resolución espacial de 30 m.La aplicación de herramientas de análisis espacial al estudio de la erosión hídrica de los suelos de la Patagonia Argentina contribuye al objetivo de definir un programa de desarrollo y manejo adecuado, en función del estado y grado de erosión potencial de los mismos.AbstractIn Argentine Patagonia there exist large extensions of lands degraded by overgrazing, this favours soil water erosion. Two million hectares are eligible for forestation (Gallo et al. 2005), with some environmental limitations that requireprevious studies to prepare development and sustainability proposals. The study area is located in the right margin of the Litrán River, 25 kms of its estuary in Aluminé Lake (Province of Neuquén). In this area, some Mapuche (araucanian) communities carry out stock breeding (mainly goats) using a migrating system. This region presents very severe Aeolian and hydrological erosion.The objective of the afforestation management plan of this land, is the design of control measures, to stop erosion, like perimeter close, afforestation and structural measures for controlling erosional gully.It is then necessary, to characterize the actual and potential erosion, that would allow to carry out with measures monitoring to implement controls and mitigation.Paper presents, pedology map by interpreting and georreferencing satellite images by a Geographical Information System. (GIS).The mapping methodology was based in Hierarchical Classification of Landforms, which is the structure of the geopedology focus for mapping soil (Zinck, 1989). The classification of actual erosion was obtained from the method of theBureau of Land Management (USDI) by visual inspection of seven aspects of erosion in surface. The estimation of the potential erosion of the floors of the forest field was carried out utilizing the Universal Soil Lost Equation (USLE) and ArcGis 9,2 (ESRI, 2006) to carry out the spatial analysis, obtaining a map of annual soil loss ( tn/has/year) with a spatial resolution of 30 m.The application of spatial analysis tools in the study of soil water erosion in Patagonia, Argentina contributes to the objective of defining define a program of development and adequate management, as a function of the state and degree of potential soil erosion