Aplicación de técnicas SIG en el estudio de evaluación de degradación de suelos. Mazarrón (Murcia)

El objetivo general de este estudio ha sido evaluar el estado actual y los cambios que se han producido en algunas características edáficas del área de Mazarrón (Murcia) en un periodo de 20 años, en relación con los procesos de degradación. Para ello se han utilizado los resultados de dos muestreos de suelos realizados en un intervalo de veinte años (1988 y 2008). Se han analizado algunas de las características edáficas que más relación tienen con la vulnerabilidad de los suelos a la erosión (Textura, Materia orgánica y Pedregosidad) y de las cuales se disponía de datos en los dos muestreos. Para la creación y análisis de la información espacial se han empleado dos Sistemas de Información Geográfica de software libre. Uno de ellos ha sido GvSIG, desarrollado por la Generalitat Valenciana y el programa GRASS. La metodología SIG empleada ha sido una herramienta fundamental para obtener la serie de capas de variables edáficas para los años 1988 y 2008. Los resultados muestran como el área de estudio es bastante vulnerable a los procesos erosivos, sobre todo por erosión hidrica y antrópica, debido a las características de sus suelos. Riesgo que se incrementaría si en futuro se abandonaran los cultivos.The main objetive of these study is to evaluate the current situation and the changes ocurred in some edaphic characteristics of the soils in the Mazarrón area (Murcia) in a twenty years period, in relation with the degradation processes. For these propose we have used the results of two soils samples carried out in a twenty years intervale (1988 and 2008). The caracteristics more related with the vulnerability of the soil erosion (texture, organic matter and stoniness) of wich we had data of the two samples were evaluated. Two Geografical Information System of free software have been used for the creation and analisis of the espacial information. One of these was GvSIG, developed by Generalitat Valenciana and GRASS programme. The GIS methodology carried out was a fundamental tool to obtain edaphic variables layers for the years 1988 and 2008. The results show how the study area is very sensible to the erosive processes, specialy by hidric and antropic erosion, because soil caracteristics. This hazard would increase in a future if the land was abandoned

Surface and subsurface flow in eucalyptus plantations in north-central Portugal

In the Baixo Vouga region of north-central Portugal, forests occupy half of the territory, of which two thirds are Eucalypts plantations. The hydrological implications of this large-scale introduction of eucalypt are unknown and the aim of this exploratory study, realized in the Caramulo Mountains, was to describe overland flow (OLF), subsurface flow (SSF) and stream flow (Q) in a catchment dominated by Eucalyptus plantations. The main conclusions are that annual OLF rate is low, spatially heterogeneous between 0.1% and 6% and concentrated during the wet season as saturation excess, particularly as return flow. Infiltration-excess OLF due to the strong soil water repellence (SWR) is dominant during dry season, but produces residual runoff amount. SSF is the principal mechanism of runoff formation. It originates from matrix flow and pipe flow at the soil-bedrock interface, principally during the wet season. Matrix flow is correlated with soil moisture (SM) content, with a threshold of 25 %. Pipe flow starts with saturation of soil bottom but without saturation of the entire soil profile, due to a large network of macropores. Stream flow response is highly correlated with matrix flow behaviour in timing and intensity. SWR induces a very patchy moistening of the soil, concentrates the fluxes and accelerates them almost 100 times greater than normal percolation of the water in the matrix

Relationship of Weather Types on the Seasonal and Spatial Variability of Rainfall, Runoff, and Sediment Yield in the Western Mediterranean Basin

Rainfall is the key factor to understand soil erosion processes, mechanisms, and rates. Most research was conducted to determine rainfall characteristics and their relationship with soil erosion (erosivity) but there is little information about how atmospheric patterns control soil losses, and this is important to enable sustainable environmental planning and risk prevention. We investigated the temporal and spatial variability of the relationships of rainfall, runoff, and sediment yield with atmospheric patterns (weather types, WTs) in the western Mediterranean basin. For this purpose, we analyzed a large database of rainfall events collected between 1985 and 2015 in 46 experimental plots and catchments with the aim to: (i) evaluate seasonal differences in the contribution of rainfall, runoff, and sediment yield produced by the WTs; and (ii) to analyze the seasonal efficiency of the different WTs (relation frequency and magnitude) related to rainfall, runoff, and sediment yield. The results indicate two different temporal patterns: the first weather type exhibits (during the cold period: autumn and winter) westerly flows that produce the highest rainfall, runoff, and sediment yield values throughout the territory; the second weather type exhibits easterly flows that predominate during the warm period (spring and summer) and it is located on the Mediterranean coast of the Iberian Peninsula. However, the cyclonic situations present high frequency throughout the whole year with a large influence extended around the western Mediterranean basin. Contrary, the anticyclonic situations, despite of its high frequency, do not contribute significantly to the total rainfall, runoff, and sediment (showing the lowest efficiency) because of atmospheric stability that currently characterize this atmospheric pattern. Our approach helps to better understand the relationship of WTs on the seasonal and spatial variability of rainfall, runoff and sediment yield with a regional scale based on the large dataset and number of soil erosion experimental stations.Spanish Government (Ministry of Economy and Competitiveness, MINECO) and FEDER Projects: CGL2014 52135-C3-3-R, ESP2017-89463-C3-3-R, CGL2014-59946-R, CGL2015-65569-R, CGL2015-64284-C2-2-R, CGL2015-64284-C2-1-R, CGL2016-78075-P, GL2008-02879/BTE, LEDDRA 243857, RECARE-FP7, CGL2017-83866-C3-1-R, and PCIN-2017-061/AEI. Dhais Peña-Angulo received a “Juan de la Cierva” postdoctoral contract (FJCI-2017-33652 Spanish Ministry of Economy and Competitiveness, MEC). Ana Lucia acknowledge the "Brigitte-Schlieben-Lange-Programm". The “Geoenvironmental Processes and Global Change” (E02_17R) was financed by the Aragón Government and the European Social Fund. José Andrés López-Tarazón acknowledges the Secretariat for Universities and Research of the Department of the Economy and Knowledge of the Autonomous Government of Catalonia for supporting the Consolidated Research Group 2014 SGR 645 (RIUS- Fluvial Dynamics Research Group). Artemi Cerdà thank the funding of the OCDE TAD/CRP JA00088807. José Martínez-Fernandez acknowledges the project Unidad de Excelencia CLU-2018-04 co-funded by FEDER and Castilla y León Government. Ane Zabaleta is supported by the Hydro-Environmental Processes consolidated research group (IT1029-16, Basque Government). This paper has the benefit of the Lab and Field Data Pool created within the framework of the COST action CONNECTEUR (ES1306)

Métodos para la estimación de la escorrentía en vertientes de litología no acuífera en ámbitos mediterráneos

The study of the slopes hydrological behavior has been and is a very recurrent subject as much from the hydrological as of the hydrodynamics optics, throughout the last decades. The Works of Ven Te Chow, (1994); Ward&Robinson, (2000); Horton, (1945); Hewlet, (1967); Smith (1970); Laveeh, (1998); Yair (1985); they constitute good examples of the necessity of explanation of the mechanisms and the relationships between surface water and channels, as well as of the timing and spatial variability of such. This preoccupation is increased in environments where the ecosystems acquire a greater diversity with differential response of the biotics and abiotics factors and, consequently, with a diverse hydrological answer. One of these environments is the Mediterranean, located between arids and humids climates with direct repercussions in the ecogeomorfological system and the hydrological behavior. And in this sense, commonly, the theory of a mechanism own of generation of slope run-off has been accepted under Mediterranean conditions, different from the existing ones in other environments: the denominated discontinuous or mixed hortonian model. This paper tries, from the hydrological optics and accepting the hydrodynamics principles of Mediterranean conditions, to establish the adjustment gears between both approaches. And once determined both models, to compare them with the results of the field experimentation, and to make the adjustments between both approaches, in order to validate the method. All applied it in two slopes of opposed orientation in middle mountains of Malaga.El estudio del comportamiento hidrológico de las vertientes ha sido y es un tema muy recurrente tanto desde la óptica hidrológica como de la hidrodinámica, a lo largo de las últimas décadas. Los trabajos de Ven te Chow, (1994); Ward&Robinson, (2000); Horton, (1945); Hewlet, (1967); Smith (1970); Laveeh, (1998); Yair (1985); constituyen buenos ejemplos de la necesidad de explicación de los mecanismos de incorporación del agua a los cauces, así como de la variabilidad espacio-temporal de los mismos. Esta preocupación se incrementa en ambientes donde los ecosistemas adquieren una mayor diversidad con incidencia diferencial de los factores bióticos y abióticos y, en consecuencia, con una diversa respuesta hidrológica. Uno de estos ambientes es el mediterráneo, a caballo entre los climas áridos y los templado-húmedos, con repercusiones directas en el sistema ecogeomorfológico y en el comportamiento hidrológico. Y en este sentido, ha sido comúnmente aceptada la teoría de un mecanismo propio de generación de escorrentía en laderas bajo condiciones mediterráneas, diferente a los existentes en otros ambientes: el denominado modelo hortoniano discontinuo o mixto. La presente investigación pretende, desde la óptica hidrológica y aceptando principios hidrodinámicos propios de condiciones mediterráneas, establecer los mecanismos de ajuste entre ambas aproximaciones. Y una vez determinados ambos modelos, compararlos con los resultados de la experimentación in situ, realizando los ajustes entre ambas aproximaciones, a fin de validar el método. Todo ello aplicado en dos vertientes de exposición opuesta en los Montes de Málaga

Variabilidad de los procesos de generación de escorrentía en laderas bajo condiciones mediterráneas

In the mediterranean conditions the classic models are not avaliables for to explain the runoff/runon processes. The Mediterranean area is a zone of special interest , because in which the classical models of generation of runoff are presenting of form combined. In this research, we analyse the possible hydrologic hehavior of two slopes with different pluviometric gradient. In which, by means of an exhaustive analysis of vegetation and the soil characteristics, we determine which could be its hydrologic behaviour attending to two types of different parameters; on the one hand, we could to cal! hydrodynamic model, its based in the mixed and discontinue Horton models (Calvo Cases, A. 2003 ), (Lavee et al. 1998), and the other hand, hydrological used in the civil engineering. According to hydrologic the results are very extremes, and a good behaviour to attending the slope hydrodynamic. Such, the vegetation pattern, its disposition, and the integration with edafological characteristics about its rainfall, has an important role.Dentro de los estudios relacionados con el análisis de los procesos de generación de escorrentía/infiltración, es el área mediterránea una zona de especial interés, especialmente porque en ella los modelos clásicos de generación de escorrentía se presentan de forma combinada. En la presenteinvestigación, analizamos el posible comportamiento hidrológico de dos laderas con diferente gradiente pluviométrico. En ellas, mediante un exhaustivo análisis de la vegetación y de las características de los suelos, determinamos cual podría ser su comportamiento hidrológico atendiendo a dos tipos de parámetros diferentes; de un lado, lo que podríamos denominar un modelo hidrodinámico, basado en los modelos hortoniano discontinúo o mixto (Calvo Cases, A. 2003), (Lavee et al. 1998), y de otro, en los cálculos hidrológicos usados habitualmente dentro del ámbito de la ingeniería civil. Los resultados obtenidos nos evidencian comportamientos más extremos atendiendo a circunstancias contempladas desde el punto de vista hidrológico, y un comportamiento más adecuado desde el punto de vista geomorfológico atendiendo a la hidrodinámica de las laderas. En todo ello, el patrón de la vegetación, su disposición, así como la integración con las características edafológicas sobre las que se produce la precipitación, ejercen un papel clave

Erosión y déficit ambiental en la cuenca del río Campanillas

Soil erosion by rainfall agresivity problems, is in enviromental sens, in the SE of Spain, a very important question, and also in the South watershed. Is the firs one factor to generalise the desertification expand procesess in the mosto f the hight lands of the watershed of the mediterranean sea. The Campanillas watershed is very representative in this way. Slope levels very hight, poor soils, a very important rainfall agresivity, and of course a reduced solils capability productive and deforestation, are the laboratory scheme of the desertification procesess.  La erosión de suelos es uno de los principales problemas desde el punto de vista medioambiental del sureste español, y concretamente en la cuenca Sur. Hasta el punto que se ha convertido en el primer causante del déficit ambiental, y principal dinamizador de los procesos de desertificación.La cuenca del río Campanillas es un buen representante a estos niveles del conjunto de cuencas que vertebran el Sur de Andalucía. Fuertes pendientes, escasos suelos, intensas precipitaciones, y por tanto, pérdida de capacidad productiva de los suelos, y deforestación, constituyen un magnífico panorama de laboratorio de los procesos de desertificación

Relaciones agua-suelo-vegetación.-Variabilidad de la disponibilidad hídrica superficial para la vegetación a lo largo de un gradiente pluviométrico

ABSTRACT A climatic gradient was defined in South of Spain with a great decreased of rainfall from West to East (>1,000 mm), which produces changes in vegetation and hydric resources. This study was carried out in five hillslopes under different climatic conditions and their aims were to analyze: the variability of available water along the gradient since 2002 to 2006, the key factors of it and the influence on the vegetal cover. Results showed that clay content had a great influence in the surface available water for plants, which did not decrease in the drier field sites, where the amount of days with hydric deficit was lower. Relationships between vegetation and soil water were stronger in the more humid field sites, where existed a feedback between both properties

Seasonal changes in the soil hydrological and erosive response depending on aspect, vegetation type and soil water repellency in different mediterranean microenvironments

Mediterranean areas are characterized by a strong spatial variability that makes the soil hydrological response highly complex. Moreover, Mediterranean climate has marked seasons that provoke dramatic changes on soil properties determining the runoff rates, such as soil water content or soil water repellency (SWR). Thus, soil hydrological and erosive response in Mediterranean areas can be highly time-as well as space-dependant. This study shows SWR, aspect and vegetation as factors of the soil hydrological and erosive response. Erosion plots were set up in the north-and the south-facing hillslope and rainfall, runoff, sediments and SWR were monitored. Soil water repellency showed a seasonal behaviour and it was presented in three out of four microenvironments after the summer, disappearing in the wet season. In general, runoff rate was higher in shrubs patches (0.47 ± 0.67 mm) than in inter-shrub soils (1.54 ± 2.14 mm), but it changed seasonally in different ways, depending on the aspect considered, decreasing in the north-facing hillslope and increasing in the south-facing one. The main factor determining the hydrological and erosive response was the rainfall intensity, regardless of the rainfall depth of the event. This response was modulated mainly by SWR in the north-facing hillslope and the vegetation pattern in the south-facing one. © 2013 Author(s)

Consequences of sealing of soil in the Field of Cartagena (Murcia)

El sellado antropogénico de los suelos constituye un proceso de degradación física y medioambiental, tanto a escala local como regional, y produce la pérdida de los recursos del suelo debido a su recubrimiento con materiales para la construcción de viviendas, carreteras, etc. El objetivo de este estudio ha sido comprobar, en el sector oriental del Campo de Cartagena (Murcia), la expansión urbanística, que ha tenido lugar en las últimas décadas y ver las consecuencias que esta ha producido en relación con el sellado de los suelos. Para la realización de este estudio, se han utilizado: imágenes áreas y de satélite de los años 1980 y 2007, trabajos de campo y recopilación de datos de las estadísticas agrarias municipales. Como conclusión merece destacarse como desde 1981 a 2007, la superficie de suelo sellada en el área de estudio ha pasado de poco más de 1.000 has a casi 4.000 has, lo que supone un aumento del 362%.The anthropogenic sealing of soils is a physical and environmental degradation process, both locally and regionally, and causes loss of soil resources due to its coating materials for housing, roads, etc. The aim of this study was to verify, in the eastern sector of the Campo de Cartagena (Murcia), urban expansion, which has taken place in recent decades and see the consequences that this has occurred in relation to soil sealing. For this study, we used: aerial imagery and satellite images of the 1980 and 2007, fieldwork and data collection of municipal agricultural statistics. As a conclusion was obtained that from 1981 to 2007, the sealed soil surface in the study area has increased from just over 1,000 has to almost 4,000 has, representing an increase of 362%

Relaciones agua-suelo-vegetación.-Incidencia del stress hídrico en las relaciones suelo-agua-planta a lo largo de un gradiente pluviométrico en el sur de España

ABSTRACT The Andalusian Mediterranean Watershed, in the South of the Iberian Peninsula, shows a climatic gradient from the Straits of Gibraltar (1,600 mm year-1) to the Cabo de Gata (150 mm year-1). Climate conditions differences are translating into variations in the elements of the eco-geomorphological system at hillslope scale. In this study has been analysed the immediate consequences of a period of two years drought (2004-06) on several elements of the Mediterranean eco-geomorphological system at three hillslopes (sub-humid, dry Mediterranean and semi-arid). The soil water content, the pattern of vegetation and some soil properties (organic matter content, aggregate stability and permeability) were analysed before (Nov-2003) and during (Nov-2005) the drought period. Final results have shown: i) reduction in soil water content which reached in the wet seasons values below wilting point, affecting negatively to the water available for vegetation and especially in the wettest sites; ii) reduction in vegetation cover and in the number of plants, especially at semi-arid field site; iii) changes in the organic matter content which aggravates the loss of stability of soil aggregates, a process seen more clearly under more arid conditions; and iv) reduction of soil permeability in all situations in the climate gradient studied, which supposes a priori an increase in erosive processes due to surface runoff. These results indicate increased vulnerability of the eco-geomorphological system because of the rainfall drought situation