Impact of Low Pressure Grazing on the Hydrological and Sediment Connectivity in Hillslopes under Contrasted Mediterranean Climatic Conditions (South of Spain)

Abstract

Many areas from the Mediterranean region are characterised by steep slope gradient, patchy vegetation cover and soil surface conditions prone to overland flow generation and sediment transport. This study evaluated the hydrological and sediment connectivity between sections (top, middle and bottom‐channel) from three low pressure grazed hillslopes located under contrasted Mediterranean climatic conditions in southern Spain. The aim was performed by installing rain‐gauge stations and opened‐plots in order to register overland flow and sediment concentration from February 2008 to January 2010. The results indicated that (i) major volumes of overland flow and sediment transport occurred more frequently in the humid and semiarid; (ii) the more frequent hydrological connectivity was observed between the middle and bottom‐channel sections, although the major values of overland flow and sediment concentration were registered in the upper sections; (iii) it was found very frequent those rainfall events in which all sections contributed with overland flow and sediment to the channel; (iv) the factors controlling hydrological and sediment connectivity varied from one site to another depending on the rainfall regime and vegetation cover, although the soil surface conditions (rock fragment cover either embedded or not embedded, crusts, annual plants, among others) were found as a key factor in all of them. In summary, the grazing activity, even being of low pressure, contributes to distance the hydrological and sediment connectivity from the response expected in the field sites, especially in that of humid Mediterranean climate: more overland flow and less sediment concentration and, vice versa, when becomes arid. Copyright © 2017 John Wiley & Sons, Ltd.

Structural and functional control of surface-patch to hillslope runoff and sediment connectivity in Mediterranean dry reclaimed slope systems

“…Mediterranean dry reclaimed mining slope systems (hereafter RMSSs) are characterized by the local convergence of high storm erosivity, poorly developed soils, scarce vegetation cover and rough topography. These characteristics can lead to the genesis of important amounts of overland flow, promoting soil erosion processes, which typically lead to rill and gully development (Nicolau and Asensio, 2000;Nicolau, 2002;Moreno-de-las-Heras et al, 2009;Martín-Moreno et al, 2018). The analysis of runoff and sediment connectivity has a critical relevance for landscape management in these human-made, water-limited environments, where the functional components of runoff and sediment connectivity (e.g.…”

“…In fact, withinslope spatial redistribution of runoff and sediment fluxes in these Mediterranean dry RMSSs feeds back into patch-scale hydrological behaviour by controlling the availability of water and soil resources for the long-term development of vegetation cover (Espigares et al, 2011;Moreno-de-las-Heras et al, 2011b;Merino-Martín et al, 2015). Furthermore, the magnitude and cross-scale transmission of runoff and sediments in these RMSSs largely determines their off-site ef-fects in the form of runoff and sediment conveyance to downstream channels and environments (Martín-Moreno et al, 2018).…”

Connectivity in hydrology and sediment dynamics

“…Some studies focus on catchment scale (e.g., van der Waal and Rowntree, 2018; Yang, & Lu, 2018), while others look at smaller scale soil processes (e.g., Thomaz, 2018; Bagarello et al, 2018). There are studies looking at land‐use effects, such as grazing (Martínez‐Murillo, Hueso‐González, & Ruiz‐Sinoga, 2018), revegetation (Lizaga, Quijano, Palazón, Gaspar, & Navas, 2018), land abandonment (Calsamiglia et al, 2018), urbanization (Ferreira, Walsh, Steenhuis, ∓ Ferreira, 2018), and effects of wild fire (Martínez‐Murillo, & López‐Vicente, 2018), and others focus on characterization of specific landscape types, including alpine (Rainato et al, 2018), badlands (Moreno‐de las Herras et al, 2019; Caraballo‐Arias, Di Stefano, & Ferro, 2018), and gullies (Conoscenti, Agnesi, Cama, Caraballo‐Arias, & Rotigliano, 2018; Zegeye et al, 2018). Also, some studies address only hydrological connectivity (e.g., Laine‐Kaulio and Koivusalo, 2018) or sediment connectivity (e.g., Porto, Walling, & Callegari, 2018), while others look at both types of connectivity (Ricci, Girolamo, Abdelwahab, & Gentile, 2018).…”

“…The studies in this Special Issue demonstrate that the connectivity framework is a useful tool to assess the effects of anthropogenic impacts or land‐use changes (e.g., Martinez‐Murillo et al, 2018; Lizaga et al, 2018; Calsamiglia et al, 2018; Dong et al, 2019; Ferreira et al, 2018) can have on the transport of water and sediment. Therefore, it can be useful for the design and implementation of management interventions.…”

Técnicas de restauración de suelos basadas en el uso de residuos orgánicos: seis años de beneficios sobre las propiedades de un suelo forestal

“…Es por ello, que su protección y conservación cobra especial relevancia cuando hablamos de ecosistemas frágiles o ecológicamente sensibles . En las áreas semiáridas Mediterráneas, las actividades antrópicas (arado en pendientes, deforestación y sobrepastoreo) y la alternancia climática de largos periodos de sequía, que se intercalan con periodos cortos de precipitación intensa, han conllevado una intensa degradación de los suelos generando una pérdida de diversidad sistémica (Casals et al, 2000;Muñoz-Rojas et al, 2016;Martínez-Murillo et al, 2017a, 2017b. Concretamente, en los suelos forestales, esto es porque la dinámica del carbono orgánico del suelo (SOC) suele estar condicionada por aquellos factores relativos a la temperatura y humedad del suelo (Ruiz-Sinoga et al, 2009;Hueso-González et al, 2014;Bretón et al, 2016).…”