Studying hydrogeochemical processes to understand hydrodiversity and the related natural and cultural heritage. The case of Los Hoyos area (South Spain)

The protection of geodiversity has been gaining interest during the last decades. However, the study of hydrodiversity has been much less developed than other aspects of the geological heritage (lithology, mineralogy, geomorphology, palaeontology). The objective of this work is to help with an inclusive definition of hydrodiversity by assessing its importance as part of geodiversity and how it can condition the natural and cultural heritage of a region. To that end, we have selected as a study area an evaporitic karst enclave of great geomorphological and environmental value located in southern Spain, named Los Hoyos, where diverse water features are found. Based on the hydrochemical and isotopic analysis of the water points, five main processes explain the hydrodiversity of the area: (1) the availability of minerals in the environment, (2) the residence time of groundwater, (3) the evaporation of water in the wetlands, (4) the common-ion effect (5) and the high ionic strength of groundwater. All these processes, directly related to the geology and geomorphology of the area (geodiversity), have given rise to diverse ecosystems (including protected wetlands), which enhance local biodiversity and geological forms (travertines), and are connected to the area's cultural heritage (salt extraction from the Paleolithic). This hydrodiversity is partially or totally responsible for a series of services to society related to its intrinsic, cultural, aesthetic, economic, functional, and scientific values. The case here presented exemplifies the importance of hydrodiversity in the natural and cultural heritage and highlights the need of advancing on the definition, promotion and protection of the hydrological heritage.