This page has only limited features, please log in for full access.
Watering ponds represent an important part of the hydrological resources in some water-limited environments. Knowledge about their storage capacity and geometrical characteristics is crucial for a better understanding and management of water resources in the context of climate change. In this study, the suitability of different geomatic approaches to model watering pond geometry and estimate pond-specific and generalized volume–area–height (V–A–h) relationships was tested. Terrestrial structure-from-motion and multi-view-stereo photogrammetry (SfM-MVS), terrestrial laser scanner (TLS), laser-imaging detection and ranging (LIDAR), and aerial SfM-MVS were tested for the emerged terrain, while the global navigation satellite system (GNSS) was used to survey the submerged terrain and to test the resulting digital elevation models (DEMs). The combined use of terrestrial SfM-MVS and GNSS produced accurate DEMs of the ponds that resulted in an average error of 1.19% in the maximum volume estimation, comparable to that obtained by the TLS+GNSS approach (3.27%). From these DEMs, power and quadratic functions were used to express pond-specific and generalized V–A–h relationships and checked for accuracy. The results revealed that quadratic functions fit the data particularly well (R2 ≥ 0.995 and NRMSE < 2.25%) and can therefore be reliably used as simple geometric models of watering ponds in hydrological simulation studies. Finally, a generalized V–A power relationship was obtained. This relationship may be a valuable tool to estimate the storage capacity of other watering ponds in comparable areas in a context of data scarcity.
Ubaldo Marín-Comitre; Álvaro Gómez-Gutiérrez; Francisco Lavado-Contador; Manuel Sánchez-Fernández; Alberto Alfonso-Torreño. Using Geomatic Techniques to Estimate Volume–Area Relationships of Watering Ponds. ISPRS International Journal of Geo-Information 2021, 10, 502 .
AMA StyleUbaldo Marín-Comitre, Álvaro Gómez-Gutiérrez, Francisco Lavado-Contador, Manuel Sánchez-Fernández, Alberto Alfonso-Torreño. Using Geomatic Techniques to Estimate Volume–Area Relationships of Watering Ponds. ISPRS International Journal of Geo-Information. 2021; 10 (8):502.
Chicago/Turabian StyleUbaldo Marín-Comitre; Álvaro Gómez-Gutiérrez; Francisco Lavado-Contador; Manuel Sánchez-Fernández; Alberto Alfonso-Torreño. 2021. "Using Geomatic Techniques to Estimate Volume–Area Relationships of Watering Ponds." ISPRS International Journal of Geo-Information 10, no. 8: 502.
Sediments accumulated in check dams are a valuable measure to estimate soil erosion rates. Here, geographic information systems (GIS) and three machine learning techniques (MARS-multivariate adaptive regression splines, RF-random forest and SVM-support vector machine) were used, for the first time, to predict sediment deposition rate (SR) in check-dams located in six watersheds in SW Spain. There, 160 dry-stone check dams (~ 77.8 check-dams km−2), accumulated sediments during a period that varied from 11 to 23 years. The SR was estimated in former research using a topographical method and a high-resolution Digital Elevation Model (DEM) (average of 0.14 m3 ha−1 year−1). Nine environmental-topographic parameters were calculated and employed as predictors of the SR. The ability of MARS, RF and SVM was evaluated by using a five-fold cross-validation, considering the entire area (ALL), the check dams on the hillslope (HILL) and the valley-bottoms (VALLEY), as well as the three catchments (B, C and D) with the highest number of check dams. The accuracy of the models was assessed by the relative root mean square error (RRMSE) and the mean absolute error (MAE). The results revealed that RF and SVM are able to predict SR with higher and more stable accuracy than MARS. This is evident for the datasets ALL, VALLEY and D, where errors of prediction exhibited by MARS were from 44 to 77% (RRMSE) and from 37 to 62% (MAE) higher than those achieved by RF and SVM, but it also held for the datasets HILL and B where the difference of RRMSE and MAE was 7–10% and 12–17%, respectively.
Christian Conoscenti; Chiara Martinello; Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez. Predicting sediment deposition rate in check-dams using machine learning techniques and high-resolution DEMs. Environmental Earth Sciences 2021, 80, 1 -19.
AMA StyleChristian Conoscenti, Chiara Martinello, Alberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez. Predicting sediment deposition rate in check-dams using machine learning techniques and high-resolution DEMs. Environmental Earth Sciences. 2021; 80 (10):1-19.
Chicago/Turabian StyleChristian Conoscenti; Chiara Martinello; Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez. 2021. "Predicting sediment deposition rate in check-dams using machine learning techniques and high-resolution DEMs." Environmental Earth Sciences 80, no. 10: 1-19.
Soil erosion by water is a frequent soil degradation process in rangelands of SW Spain. The two main erosive processes in these areas are sheetwash erosion in hillslopes and gully erosion due to concentrated flow in valley bottoms. Land use changes and overgrazing play a key role in the genesis and development of gullies and gully erosion is a frequent process with negative consequences at the valley bottoms of these landscapes.
The development of new techniques allows monitoring of gully dynamics with an increase at spatial and temporal resolutions. Here we present a detailed study of a valley-bottom gully in a Mediterranean rangeland with a savannah-like vegetation cover that was partially restored in February 2017. Restoration activities included check dams (gabion weirs and fascines) and livestock exclosure by fencing. The objectives of this study were: (1) to analyze the effectiveness of the restoration measures, (2) to study erosion and deposition dynamics before and after the restoration activities, (3) to examine the role of micro-morphology on the observed topographic changes and (4) to compare the current and recent channel dynamics with previous studies conducted in the same study area through different methods and spatio-temporal scales, quantifying medium-term changes. Topographic changes were estimated using multi-temporal high-resolution DEMs produced using Structure-from-Motion (SfM) photogrammetry and aerial images acquired by a fixed-wing Unmanned Aerial Vehicle (UAV). DEMs and orthophotographs with a Ground Sampling Distance of 0.02 m were produced by means of SfM photogrammetric techniques. The average Root Mean Square Error (RMSE) estimated during the SfM processing was 0.03 m.
The performance of the restoration activities was satisfactory to control gully erosion. Check dams were effective favoring sediment deposition and reducing lateral bank erosion. Nevertheless, erosion was observed immediately downstream in 9% of the check dams. Livestock exclosure in the most degraded area promoted the stabilization of bank headcuts and revegetation. The sediments retained behind check dams reduced the longitudinal slope gradient of the channel bed and established a positive feedback mechanism for channel revegetation.
Keywords: gully erosion, restoration, topographic change, UAV+SfM, rangeland.
Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel. Spatio-temporal dynamics of erosion and deposition in a partially restored valley-bottom gully. 2021, 1 .
AMA StyleAlberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez, Susanne Schnabel. Spatio-temporal dynamics of erosion and deposition in a partially restored valley-bottom gully. . 2021; ():1.
Chicago/Turabian StyleAlberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel. 2021. "Spatio-temporal dynamics of erosion and deposition in a partially restored valley-bottom gully." , no. : 1.
Gullies are sources and reservoirs of sediments and perform as efficient transfers of runoff and sediments. In recent years, several techniques and technologies emerged to facilitate monitoring of gully dynamics at unprecedented spatial and temporal resolutions. Here we present a detailed study of a valley-bottom gully in a Mediterranean rangeland with a savannah-like vegetation cover that was partially restored in 2017. Restoration activities included check dams (gabion weirs and fascines) and livestock exclosure by fencing. The specific objectives of this work were: (1) to analyze the effectiveness of the restoration activities, (2) to study erosion and deposition dynamics before and after the restoration activities using high-resolution digital elevation models (DEMs), (3) to examine the role of micro-morphology on the observed topographic changes, and (4) to compare the current and recent channel dynamics with previous studies conducted in the same study area through different methods and spatio-temporal scales, quantifying medium-term changes. Topographic changes were estimated using multi-temporal, high-resolution DEMs produced using structure-from-motion (SfM) photogrammetry and aerial images acquired by a fixed-wing unmanned aerial vehicle (UAV). The performance of the restoration activities was satisfactory to control gully erosion. Check dams were effective favoring sediment deposition and reducing lateral bank erosion. Livestock exclosure promoted the stabilization of bank headcuts. The implemented restoration measures increased notably sediment deposition.
Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel. Dynamics of Erosion and Deposition in a Partially Restored Valley-Bottom Gully. Land 2021, 10, 62 .
AMA StyleAlberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez, Susanne Schnabel. Dynamics of Erosion and Deposition in a Partially Restored Valley-Bottom Gully. Land. 2021; 10 (1):62.
Chicago/Turabian StyleAlberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel. 2021. "Dynamics of Erosion and Deposition in a Partially Restored Valley-Bottom Gully." Land 10, no. 1: 62.
Manuel Pulido Fernández; Ali Keshavarzi; Jesús Rodrigo-Comino; Susanne Schnabel; Joaquín Francisco Lavado Contador; Álvaro Gómez Gutiérrez; Francisco Javier Lozano Parra; Jesús Barrena González; Alberto Alfonso Torreño; Artemi Cerdà. Developing scoring functions to assess soil quality at a regional scale in rangelands of SW Spain. Revista Brasileira de Ciência do Solo 2020, 44, 1 .
AMA StyleManuel Pulido Fernández, Ali Keshavarzi, Jesús Rodrigo-Comino, Susanne Schnabel, Joaquín Francisco Lavado Contador, Álvaro Gómez Gutiérrez, Francisco Javier Lozano Parra, Jesús Barrena González, Alberto Alfonso Torreño, Artemi Cerdà. Developing scoring functions to assess soil quality at a regional scale in rangelands of SW Spain. Revista Brasileira de Ciência do Solo. 2020; 44 ():1.
Chicago/Turabian StyleManuel Pulido Fernández; Ali Keshavarzi; Jesús Rodrigo-Comino; Susanne Schnabel; Joaquín Francisco Lavado Contador; Álvaro Gómez Gutiérrez; Francisco Javier Lozano Parra; Jesús Barrena González; Alberto Alfonso Torreño; Artemi Cerdà. 2020. "Developing scoring functions to assess soil quality at a regional scale in rangelands of SW Spain." Revista Brasileira de Ciência do Solo 44, no. : 1.
The main goal of this study was to identify the problems that are putting the viability of watering ponds at risk. For doing that, we have analyzed five different study cases: (I) livestock consumption, Mediterranean climate (rangelands of SW Spain), (II) multifunctional ponds (Arroyo de la Luz, Spain), (III) ecotourism (Valdepajares de Tajo, Spain), (IV) crop irrigation and fish farming, semi-arid climate (the wilaya of Ouargla, Algeria), and (V) livestock consumption, humid subtropical climate (Prudentópolis, Brazil). The identification of problems was made through surveys, personal interviews, local knowledge and literature review as well as through the analysis of water quality parameters such as the concentration of phosphates and fecal coliforms in some ponds. We have identified problems of water shortage (ca. 50% of rangeland farmers), pollution induced by agriculture (maximum values of phosphates = 1.33 mg L−1) and livestock farming (maximum value of fecal coliforms ≈ 7000 cfu mL−1), low potability for human consumption (score: 2.8/7.0), invasive species such as Azolla filiculoides (10 out of 17 watering ponds), high water temperature for aquaculture in summer (Algeria) and the increase of turbidity in nearby water courses due to the actions of free-fattening pigs (Brazil), among many other problems. We conclude an extra effort by stakeholders is still needed in order to agree mitigation strategies.
Manuel Pulido; Alberto Alfonso-Torreño; Jesús Barrena-González; Rafael Robina-Ramírez; Mohamed Amine Abdennour. Identifying Problems in Watering Ponds with Different Purposes. Environments 2020, 7, 63 .
AMA StyleManuel Pulido, Alberto Alfonso-Torreño, Jesús Barrena-González, Rafael Robina-Ramírez, Mohamed Amine Abdennour. Identifying Problems in Watering Ponds with Different Purposes. Environments. 2020; 7 (9):63.
Chicago/Turabian StyleManuel Pulido; Alberto Alfonso-Torreño; Jesús Barrena-González; Rafael Robina-Ramírez; Mohamed Amine Abdennour. 2020. "Identifying Problems in Watering Ponds with Different Purposes." Environments 7, no. 9: 63.
Water is a key strategic resource, particularly in Mediterranean climate-type areas with impermeable rocks and shallow soils like Southwestern Spain. The region of Extremadura is commonly known by its large surface occupied by big dams (30% of water dammed in Spain) although this theoretical abundance of water does not hide other problems of use. In this study, we have interviewed 132 people from the municipality of Arroyo de San Serván in order to know what the problems related to water use are, especially those that concern local people the most. Regarding the use of water at home, 90% of interviewees spend less than 60 EUR per month for water and their mean degree of satisfaction about the service is 3.7 out of 7. The reason for this low value can be the excessive content of calcium and bad taste according to 82.1%. Therefore, 64.2% of people do not usually drink water from the tap. Around two thirds of these local people usually buy water in the supermarket or drink filtered water. Concerning agricultural activities, local people gave great importance to irrigation as a source of employment (5.6/7) and inputs (4.5/7), although their satisfaction decreases about the current price of water for agriculture (0.02 EUR m−3). In addition, they are really worried about the overuse of fertilizers and herbicides (5.4/7) and they think about the necessity of taking measures to reduce these problems (6.1/7) as well as to reduce some management problems such as supply cuts. In the last few years, private (swimming pools) and public leisure facilities (swimming pool and spa) have been built in spite of not being considered important by local people (3.6–4.0/7). Nevertheless, about 60% of them consider these common facilities very positive in terms of employment, tourism attractions and entertainment for local people.
Manuel Pulido; Jesús Barrena-González; Alberto Alfonso-Torreño; Rafael Robina-Ramírez; Saskia Keesstra. The Problem of Water Use in Rural Areas of Southwestern Spain: A Local Perspective. Water 2019, 11, 1311 .
AMA StyleManuel Pulido, Jesús Barrena-González, Alberto Alfonso-Torreño, Rafael Robina-Ramírez, Saskia Keesstra. The Problem of Water Use in Rural Areas of Southwestern Spain: A Local Perspective. Water. 2019; 11 (6):1311.
Chicago/Turabian StyleManuel Pulido; Jesús Barrena-González; Alberto Alfonso-Torreño; Rafael Robina-Ramírez; Saskia Keesstra. 2019. "The Problem of Water Use in Rural Areas of Southwestern Spain: A Local Perspective." Water 11, no. 6: 1311.
Sediments retained in hydrological correction check dams are a useful source of information to understand soil erosion rates and sediment fluxes. Two hundred sixty nine check dams distributed in an area of 239 ha in SW Spain accumulated sediments over a period of 11 to 23 years. The aim of this work is to estimate the volume of sediments deposited in those check dams and to study the spatial variability of the accumulated sediments and its relationships with different environmental variables. The methodology included five steps: 1) flying the study area with a fixed-wing Unmanned Aerial Vehicle to capture high-resolution aerial photographs, 2) Structure-from-Motion photogrammetry, 3) processing the obtained point clouds and Digital Elevation Models (DEMs) to create the current topography and model the past soil surface, 4) estimating the volume of sediments behind each check dam using a topographic technique and 5) exploring the relationship between sediments and different environmental variables. A total of 269 check dams were identified, from which 160 were suitable to quantify the deposited sediment volume. The volume of sediments trapped by individual check-dams ranged from 0 to 108.35 m3, with an average deposition rate of 0.141 m3 ha−1 y−1. The 77% of the check dams retained <1 m3 of sediment. The topographic position and the size of the dam wall played a fundamental role in explaining the differences of total sediment accumulation as well as the deposition rates. Deposition rate was negatively correlated with drainage area, connectivity index, stream power index, topographic wetness index, upstream channel length and the number of upstream check dams. Conversely, deposition rate was positively correlated with the slope of the channel. Those dams located in valley bottoms with longer walls retained more sediment, while those of hillslopes with shorter check dam walls were ineffective.
Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel; J. Francisco Lavado Contador; José Juan De Sanjosé Blasco; Manuel Sánchez-Fernánez. sUAS, SfM-MVS photogrammetry and a topographic algorithm method to quantify the volume of sediments retained in check-dams. Science of The Total Environment 2019, 678, 369 -382.
AMA StyleAlberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez, Susanne Schnabel, J. Francisco Lavado Contador, José Juan De Sanjosé Blasco, Manuel Sánchez-Fernánez. sUAS, SfM-MVS photogrammetry and a topographic algorithm method to quantify the volume of sediments retained in check-dams. Science of The Total Environment. 2019; 678 ():369-382.
Chicago/Turabian StyleAlberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel; J. Francisco Lavado Contador; José Juan De Sanjosé Blasco; Manuel Sánchez-Fernánez. 2019. "sUAS, SfM-MVS photogrammetry and a topographic algorithm method to quantify the volume of sediments retained in check-dams." Science of The Total Environment 678, no. : 369-382.
Rangeland (known as Dehesas or Montados) is a characteristic ecosystem of the southwestern part of the Iberian Peninsula that occupies approximately 3.5 million ha, representing the most important agrosilvopastoral system in Europe. Nowadays, this situation is changing, being under circumstances of threat due to different aspects that are causing degradation of holm oaks and cork oaks throughout the Iberian Peninsula. These problems are of various kinds, accentuating the disease or syndrome of seca, tree death caused by Phytophthora cinnamomi. For the development of death susceptibility models, maximum entropy algorithms (MAXENT) were used, often widely used in ecological niche models. In the development of models, a wide range of variables (dependents and predictive), both climatic or bioclimatic, geological or soil, vegetation and economic and geographical characteristics were used. The study was carried out at two scales, the Autonomous Community of Extremadura in its entirety, and another more specific work scale, such as seca focus in protected natural areas within the Natura 2000 Network. The regional model showed a total of 1,179,639 ha prone to be affected by this condition, among which, 383,339 ha showed a high potential risk level of seca presence. These models, carried out at local scale in 4 polygons selected within the Natura 2000 Network, showed more than 70% of the land surface studied as areas with risk of suffering seca.
Álvaro Tejeda-Corvillo; Jesús Barrena-González; Joaquín Francisco Lavado-Contador; Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Manuel Pulido-Fernández. Spatial Models Predictive of “Seca” Risk in Extremadura. Applications at Regional and Local Scale in Protected Natural Areas. Proceedings 2019, 30, 58 .
AMA StyleÁlvaro Tejeda-Corvillo, Jesús Barrena-González, Joaquín Francisco Lavado-Contador, Alberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez, Manuel Pulido-Fernández. Spatial Models Predictive of “Seca” Risk in Extremadura. Applications at Regional and Local Scale in Protected Natural Areas. Proceedings. 2019; 30 (1):58.
Chicago/Turabian StyleÁlvaro Tejeda-Corvillo; Jesús Barrena-González; Joaquín Francisco Lavado-Contador; Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Manuel Pulido-Fernández. 2019. "Spatial Models Predictive of “Seca” Risk in Extremadura. Applications at Regional and Local Scale in Protected Natural Areas." Proceedings 30, no. 1: 58.
Gully erosion in valley bottoms is a frequent process with negative consequences in the dehesa environment. Soil loss, decrease of soil and descend in biomass are among the negative aftereffect of gully erosion processes. Studies conducted in agrosilvopastoral systems described the dynamics of gullied channels by means of fixed topographic cross sections or with low spatial resolution Digital Elevation Models (DEMs). Currently, high spatial and temporal resolution DEMs can be produced with spatially distributed information due to the development of new systems, platforms and sensors. Additionally, the rainfall and sediment discharge could also be monitored. This control allows us to relate gully erosion with catchment hydrology. The goals are (1) to quantify the sediment budgets by the spatio-temporal distribution of erosion and/or deposition in the gullied channel, (2) to interpret the geomorphic processes driving erosion and deposition and (3) to analyze the relationship between the morphological change and the catchment runoff and the sediment load. The studied area is a gullied channel located in the SW Iberian Peninsula and developed over a recent sedimentary deposit. The channel reaches an extension of 1 km in length and 2 m in depth. The methodology included the following steps: (1) flying the same study area with different time periods using a fixed-wing small Unmanned Aerial System (sUAS) to capture high-resolution aerial images and surveying Ground Control Points (GCPs) using a GNSS, (2) Structure-from-Motion photogrammetry processing using the acquired images and the GCPs to produce high-resolution DEMs for each date, (3) Applying the DEMs of difference approach to estimate topographic changes and to quantify the sediment budget and finally (4) analyzing the relationship between rainfall events, discharge, sediment load and changes in the channel previously estimated. Resulting DEMs and orthophotographs showed a Ground Sampling Distance of 0.02 m with a georeferencing Root Mean Square Error of 0.03 m. A spatially variable threshold (to differentiate actual geomorphic change from noise or errors) was produced using a Fuzzy Inference System and considering photogrammetric errors, slope and vegetation as factors. The applied method proved to be suitable to interpret the geomorphic changes for the gullied channel. For the 2016–2018 period, the gully showed a positive balance indicating accumulation of sediments coming from the hillslopes of the catchment. It is the period with the highest rainfall when numerous events generated runoff. On the contrary, for the period 2018–2019 a total soil loss of −119 m3 was estimated.
Alberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel; J. Francisco Lavado Contador; Manuel Pulido Fernández; Jesús Barrena-González. Monitoring Geomorphic Change and Catchment Sediment Production to Understand the Erosive Dynamics in a Gullied Channel by Means of High-Resolution DEMs. Proceedings 2019, 30, 56 .
AMA StyleAlberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez, Susanne Schnabel, J. Francisco Lavado Contador, Manuel Pulido Fernández, Jesús Barrena-González. Monitoring Geomorphic Change and Catchment Sediment Production to Understand the Erosive Dynamics in a Gullied Channel by Means of High-Resolution DEMs. Proceedings. 2019; 30 (1):56.
Chicago/Turabian StyleAlberto Alfonso-Torreño; Álvaro Gómez-Gutiérrez; Susanne Schnabel; J. Francisco Lavado Contador; Manuel Pulido Fernández; Jesús Barrena-González. 2019. "Monitoring Geomorphic Change and Catchment Sediment Production to Understand the Erosive Dynamics in a Gullied Channel by Means of High-Resolution DEMs." Proceedings 30, no. 1: 56.
Hydrological processes were investigated since the year 2000 in a semiarid rangeland with disperse cover of evergreen holm oaks. In this article results are presented on the spatial variation of rainfall in the catchment using a network of 6 raingauges. Results are also presented on soil water dynamics, which were studied under different vegetation covers and varying soil depths. Furthermore, the temporal variation of runoff generation in the basin outlet is reviewed, taking into account different timescales. The following results can be highlighted: Spatial variation of rainfall in the catchment at annual or monthly scale was low. However, large dispersion exists in the case of individual rainstorms, when the differences between the 6 raingauges varied strongly, both for daily values as well as maximum intensities. Events with high spatial variation are presumably related with small, localized storms, particularly those of high intensity and short duration, and those showing low variation are probably of frontal origin. Soil moisture presented seasonal patterns clearly dependent on factors such as rainfall or evapotranspirative demand. Spatial distribution of soil moisture was mainly affected by physiographic terrain characteristics and vegetation covers. Generally, in dry hydrological years, soil moisture was lower beneath than beyond the tree canopies, while the opposite was observed in wet years. Dry situations increase the intensity and duration of soil water deficits, enhance the evaporative demand and increment water storage capacity by covers. Channel flow in dehesas depends highly on the antecedent moisture conditions and particularly on the water content of the sediment-filled valley bottoms. If these areas become saturated, high amounts of runoff are produced during rainfall events. Under high intensity rainstorms Hortonian overland flow is rapidly generated on hillslopes producing a quick channel response. Interannual runoff variation is very high, the more frequent low rainfall years provoke very low total water flow, contrasting with less frequent years of above average rainfall, which are the ones producing high total runoff. It can be concluded that the hydrological dynamics in Mediterranean rangelands with a disperse tree cover are complex, both regarding soil water and catchment runoff, being highly variable in time. Future changes in land use or climate could affect notably the hydrological dynamics of the catchment, and hence similar upland basins. For example, a notable increase of tree cover would reduce water availability of pasture plants, particularly during dry years. A decrease of annual rainfall amounts and/or increased drought intensities, as a consequence of climate change, would enlarge periods of soil moisture deficit for pasture plants, as well as a reduction of runoff.
Susanne Schnabel; J. Lozano-Parra; A. Gómez-Gutiérrez; Alberto Alfonso-Torreño. Hydrological dynamics in a small catchment with silvopastoral land use in SW Spain. Cuadernos de Investigación Geográfica 2018, 44, 1 .
AMA StyleSusanne Schnabel, J. Lozano-Parra, A. Gómez-Gutiérrez, Alberto Alfonso-Torreño. Hydrological dynamics in a small catchment with silvopastoral land use in SW Spain. Cuadernos de Investigación Geográfica. 2018; 44 (2):1.
Chicago/Turabian StyleSusanne Schnabel; J. Lozano-Parra; A. Gómez-Gutiérrez; Alberto Alfonso-Torreño. 2018. "Hydrological dynamics in a small catchment with silvopastoral land use in SW Spain." Cuadernos de Investigación Geográfica 44, no. 2: 1.
La variación espacial es una característica identificadora de la pluviometría peninsular, pero se desconoce para cuencas pequeñas y sobre todo a escala temporal de episodios de lluvia. El objetivo es analizar la variación espacial de las precipitaciones a diferentes escalas temporales en una pequeña cuenca hidrográfica. Los análisis incluyen el cálculo de las precipitaciones medias de la cuenca utilizando el método de la media aritmética y el de los Polígonos de Thiessen. En el estudio de la variabilidad espacial de las precipitaciones a escala de evento se establecieron seis grupos en función de las cantidades diarias y de las intensidades como criterios. Los principales resultados muestran que los pluviómetros ubicados en las zonas más altas, registraron mayores precipitaciones, donde la orientación del relieve y la exposición a los vientos repercuten en la variabilidad espacial. En cuanto a los episodios de precipitación, aquellos con mayores intensidades presentan una mayor variabilidad espacial.
Alberto Alfonso-Torreño; Susanne Schnabel. Variación espacial de las precipitaciones en una pequeña cuenca hidrográfica del suroeste de España. Geographicalia 2017, 65 .
AMA StyleAlberto Alfonso-Torreño, Susanne Schnabel. Variación espacial de las precipitaciones en una pequeña cuenca hidrográfica del suroeste de España. Geographicalia. 2017; (69):65.
Chicago/Turabian StyleAlberto Alfonso-Torreño; Susanne Schnabel. 2017. "Variación espacial de las precipitaciones en una pequeña cuenca hidrográfica del suroeste de España." Geographicalia , no. 69: 65.