New trends related to market incomes, cultural human development, non-sustainable soil management practices, and climate change are affecting land abandonment in Mediterranean sloping vineyards. It is generally accepted that hydrological processes and, subsequently, soil erosion rates are usually different between cultivated and abandoned soils. However, these alterations are still poorly studied in relation to the general weather conditions in vineyards and abandoned vineyards. Thus, the main goals of this research are to (1) estimate the differences in soil properties, (2) quantify water and soil losses due to rainfall and specific soil management practices, and (3) analyze which kind of weather type and rainfall event is able to generate specific surface flows and soil loss rates. To achieve these goals, we focused on the specific case of the sloping vineyards of the Montes de Málaga (South Spain). We used 4 paired-erosion plots with Gerlach troughs to quantify soil loss and surface flow and conducted an analysis of the weather conditions during each rainfall event. The weather types that generated the highest amount of rainfall in the studied area came from the western (32.6%) and southeast (28.2%) types. The low rainfall events came from the south type (5.9%) and at the 500 hPa level, whereas the rainiest ones came from the southwest (47.7%) and south (34.1%). It is confirmed that there is a bimodality in the rainfall patterns. The results of soil erosion showed that there is a mixed mechanism depending on the state of the soil (vegetation cover, compaction, and initial soil moisture), soil management (tillage, trampling effect, and the use of herbicides). It is observed that the intensity of surface flow is highly correlated to the total rainfall amount and intensity. In the poorly managed abandoned plot, it is important to remark that the effect of tillage in the past, the elimination of the vegetation cover to preserve the soil in bare condition, and its use as a grazing area by cultivating barley highly affects the generation of the highest erosive events. Therefore, it is confirmed that these soil management options are not the most sustainable way to conserve the soil after the abandonment of cultivation.

Soil quality indexes (SQIs) are very useful in assessing the status and edaphic health of soils. This is particularly the case in the Mediterranean area, where successive torrential rainfall episodes give rise to erosion and soil degradation processes; these are being exacerbated by the current climate crisis. The objective of this study was to analyze the soil quality in two contrasting Mediterranean watersheds in the province of Malaga (Spain): the middle and upper watersheds of the Rio Grande (sub-humid conditions) and the Benamargosa River (semi-arid conditions). Field soil sampling was carried out at representative sites, and the soils were subsequently analyzed for various edaphic properties in the laboratory. From the resulting data, the mean values have been grouped and reclassified, and, based on a multicriteria evaluation, an SQI for the study region was generated. The results show that there are major differences between the two watersheds, with optimal soil quality values being found in the Rio Grande watershed (very high soil quality—34.26%), but more unfavorable values occurring throughout most of the Benamargosa River watershed (very low soil quality—63.33%). Thus, these results have been subjected to a validation process in the field.

Assessing soil hydrological conditions can provide essential information for understanding the environmental processes that affect ecosystem services and, particularly in the context of ongoing climate change. This is key in areas affected by water scarcity such as the Mediterranean belt. Therefore, the main goals of this research are (i) to assess the main rainfall dynamics and trends of some representative hotspots along with southern Spain and (ii) to determine the impact on the soil available water content (AWC) over the last two decades. An analysis of daily precipitation and soil hydrological conditions was combined with soil sampling (543) and laboratory analyses to evaluate the properties related to the soil infiltration and retention capacity. The results show that the organic factors control soil properties and their hydrodynamics in southern Spain. Furthermore, a general declining trend in soil water availability is observed over the last two decades. This is more extreme in arid and semi-arid areas, where there have been several years in the last decade with more than 200 days without the available water content. Moreover, in these areas, heavy rainfall during specific moments of the year is the key factor that manifests a greater incidence in areas with steeper slopes, which in turn, also conditions the biological factors and the hydrodynamics of the soil. In short, in the context of climate change, the analysis of soil hydrological dynamics could be used to identify biodiversity thresholds in the Mediterranean area and even to detect phenological changes in specific plant species.

El incremento de la frecuencia de la torrencialidad en ámbitos mediterráneos es una cuestión preocupante y no solo desde el punto de vista hidrogeomorfológico, sino también desde el humano, socioeconómico e infraestructural. La definición del umbral de torrencialidad es clave para determinar la peligrosidad de un territorio determinado. En este estudio ajustamos diferentes clasificaciones de torrencialidad con los problemas e impactos identificados en dos áreas mediterráneas contrastadas de la provincia de Málaga, una de ellas caracterizada por un clima mediterráneo subhúmedo (Guadalhorce), y otra por un clima mediterráneo seco-semiárido (Axarquía). A partir del análisis de los datos pluviométricos de 18 observatorios (Red SAIH), los resultados determinan una escasa recurrencia de los eventos torrenciales predefinidos (>100 mm 24 h-1; >60 mm h-1), razón por la que proponemos el uso de un nuevo umbral de torrencialidad de menor duración, pero mucha más elevada intensidad (>10 mm 10 min-1), debido a que son muchos los episodios producidos por debajo de los umbrales anteriores, pero con consecuencias territoriales, como hemos constatado en el análisis mediático. La precipitación que se ajusta a este criterio ha sido definida como “precipitación geomorfológica” por su elevada capacidad de generar alteraciones en los componentes superficiales del territorio. Este tipo de precipitación presenta en ambos ambientes una alta recurrencia, un periodo de retorno prácticamente anual y una elevada erosividad.