[EN] The Peñalén municipality (Guadalajara Province) houses a series of derelict kaolin mines. The environmental impact of these mined lands upon the close Upper Tagus Natural Park is subject to constant discussion. This works shows a characterization of the geomorphic setting of the mines, as a main determining factor of the hydrological impact. In addition, an evaluation of the soil erosion rates of the Peñalén catchment was carried through RUSLE 1.06, to identify the main sediment sources. Additionally, sediment yield quantification was feasible from the evaluation of the stored sediments at a check-dam located at the the Peñalén catchment’s mouth. Finally, a descriptive analysis of the erosive landforms at these mined areas has been made both from field work and a combination of oblique aerial photos of different times. The higher erosion rates obtained by RUSLE 1.06 are: highwall (202.54 Mg ha-1 year- 1); highwall’s debris slope deposits (87.55 Mg ha-1 year-1); outslope spoil heaps (86.12 Mg ha-1 year-1) and natural gullies (197.93 Mg ha-1 year-1). The quantification from the check-dam sedimentation offers a realistic value of the sediments that are being emitted from the Peñalén catchment to the Tagus River (approximately 3200 Mg year-1). Finally, the geomorphic analysis from oblique aerial photos and field work shows that the outslope spoil heaps of Santa Engracia mine are the main source of sediments, in contradiction with the RUSLE 1.06. From these results, three evidences are noticeable: (i) the derelict mined areas of Peñalén are located in very vulnerable topographical positions to the hydric erosion; (ii) these mined areas are subject to very high erosion rates; (iii) there is a direct hydrological connection between the sediment sources of these mined areas and the Tagus River within the protected area, and therefore a permanent and severe ecohydrologic impact is taking place.

[ES] El municipio de Peñalén (Guadalajara) alberga un conjunto de minas y escombreras degradadas, cuyo impacto ambiental sobre el inmediato Parque Natural del Alto Tajo es objeto de constante discusión. En este trabajo se ha llevado a cabo una primera aproximación al problema, tratando de caracterizar los condicionantes geomorfológicos del impacto hidrológico, de identificar las principales fuentes de sedimentos y de cuantificar los sedimentos que son emitidos desde estas zonas mineras y desde sus alrededores a la red fluvial. Esta aproximación ha puesto de manifiesto tres evidencias claras: (i) las zonas mineras de Peñalén se sitúan en localizaciones muy vulnerables a la erosión hídrica; (ii) los procesos erosivos y de emisión de sedimentos hacia el río Tajo son muy importantes desde esas zonas mineras y desde cárcavas naturales; (iii) existe una conexión hidrológica directa entre las fuentes de sedimentos de las zonas mineras degradadas de Peñalén y el río Tajo.

Peer reviewed