Evaluación de los recursos hídricos en explotaciones de ganadería extensiva del suroeste ibérico

Abstract

The construction of watering ponds has been one of the most widespread adaptive solutions in dehesa farms to face the problem of water scarcity typical of SW Iberia. The purpose of this study is to deepen the knowledge of such infrastructures, addressing three relevant aspects of them: i) their operation from a hydrological point of view, ii) their geometry, and iii) the quality of their waters. For the hydrological characterization of watering ponds, a methodology was developed to analyze their hydrological response under different climatic conditions and to derive basic guidelines for their design and location. In relation to the geometric characterization, the suitability of different geomatic techniques to obtain the bathymetry of watering ponds was tested. In this regard, terrestrial SfM-MVS photogrammetry proved to be an efficient, low-cost, and high-accuracy alternative to Laser-based survey techniques or more time-consuming GNSS surveys. The digital elevation models derived from this study were used to obtain a volume-area relationship that could be applied to estimate the storage capacity of other ponds in the region from their surface areas. Finally, the water quality was analyzed in 26 ponds, evaluating its suitability for livestock consumption, as well as the influence of some climatic, physical and management factors. The results revealed high levels of bacterial contamination of fecal origin in some ponds during the summer, with the consequent risk to animal health.