Caracterización y funcionalidad hidrológica de los suelos de una cuenca pre-pirenaica (Bidasoa, Navarra)

Resum

Soil characteristics and its hydrological properties are mayor factors affecting the hydrological processes of a catchment, which are directly affected by land cover and its management. A better understanding of the water-soil-vegetation system is essential for reliable hydrological modeling, which results should be considered in developing sustainable land and water management strategies, in a context of adaptation to climate change. To this aim, a detailed chemical and physical charac- terization of soil properties consisting of 172 sample points has been conducted at the Cantabrian Bidasoa catchment (681 km2). Analyses reveal a great relation between chemical characteristic and surrounding geology, whilst land cover is the main element affecting physical properties. So as to understand the influence of this factors into the hydrological functionality of soils, four soil-moisture stations and a meteorological one were installed in different land covers (pine forest, oak forest, grassland and fernery), within an homogeneous geological and meteorological setting (one meter deep silt-loamy textured soils). Data show that soil-moisture dynamics are deeply influenced by top vegetation cover. While superficial soil-moisture in grassland closely mirrors precipitation patterns, soil-moisture variations under forests are more attenuated. Furthermore, soil with grassland cover retains more water than tree cover, where infiltration to deeper layers is faster. Knowledge regar- ding hydrological functionality of soil under different land covers will be integrated into hydrological modeling, which is necessary for better consideration of the adaptation measures that should be taken from the territory.