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In the context of the Sustainable Development Goals (SDG), understanding landscape evolution is essential to design long-term management plans. In agricultural fields, such as the vineyards on steep slopes, the terraces offer one of the most important morphological changes. However, it is not clear if the poorly managed agricultural terraces are optimal to reduce soil erosion and overland flow, although the trafficability is improved. Therefore, the main aim of this research is to compare the differences between initial soil erosion processes on poorly managed terraced vineyards and sloping vineyards at the pedon scale, considering the key role of the SSC (Soil Surface Components). To achieve this goal, twenty-six rainfall simulations were performed, considering the inclination, vegetation and stone covers, and surface roughness. Our research was carried out in the sloping vineyards (>20°) of the Almachar municipality, in the Montes de Malaga (Spain). Those vineyards are characterized by bare soils, low organic matter and high rock fragment contents. Our results showed that higher soil losses (42.2 g m−2 vs 9.4 g m−2) and runoff (4.9 l m−2 vs 1.6 l m−2) were detected in the plots of the poorly managed terraced vineyard than in the sloping one. Moreover, the time to runoff generation was lower in the poorly conserved terraces (232 s) than in the sloping vineyard (679 s), showing a faster saturation capacity. The SSC considered as the key factors were the reduction of the stone cover and an increase of roughness. As a conclusion, we confirm that the imminent transformation from sloping vineyards into terraced fields could lead several land degradation processes if a poor management is carried out, and no control measures are applied during the process, such as the conservation of stone walls or vegetation cover above the embankment, which is not in compliance with the SDG.

The endemic argan tree (Argania spinosa) populations in South Morocco are highly degraded due to overbrowsing, illegal firewood extraction and the expansion of intensive agriculture. Bare areas between the isolated trees increase due to limited regrowth, but show lower soil quality than their neighbouring tree areas. Hypothetically, spatial differences of soil quality of the intertree area should result from translocation of litter or soil particles (by runoff and erosion or wind drift) from canopy-covered areas to the intertree areas. 385 soil samples were taken around the tree from the trunk along the tree drip line (within and outside the tree area) as well as the intertree area between two trees in four directions (upslope, downslope and in both directions parallel to the slope) and analysed for soil moisture, pH, electrical conductivity, percolation stability, total nitrogen content, content of soil organic carbon and C / N ratio. 74 tension-disc infiltrometer experiments were performed near the tree drip line, within and outside the tree area, to measure the unsaturated hydraulic conductivity. We found that the tree influence on its surrounding intertree area is limited, with e.g., Corg- & N-content decreasing significantly from tree trunk to tree drip line. However, intertree areas near the tree drip line differed significantly from intertree areas between two trees, yet only with a small effect. Trends for spatial patterns could be found in eastern and downslope directions due to wind drift and slope wash. Soil moisture was highest in the north due to shade from the midday sun, the influence extended to the intertree areas. The unsaturated hydraulic conductivity also showed significant differences between areas within and outside the tree area near the tree drip line. Although only limited influence of the tree on its intertree area was found, the spatial pattern around the tree suggests that reforestation measures should be aimed around tree shelters in northern or eastern directions with higher soil moistures, N- or Corg-content to ensure seedling survival.

A sound understanding of erosive processes at different scales can contribute substantially to the design of suitable management strategies. The main aim of this work was to evaluate key factors at the pedon scale that cause soil erosion to occur. To achieve this goal, we quantified infiltration, permeability, soil losses and runoff volumes in a small Southern Spanish catchment cultivated with olive orchards. To assess which factor contributed most to speeding up soil erosion, a Spearman rank coefficient and principal components analysis were carried out. The results confirmed low infiltration values (11.8 mm h−1) in the surface soil layers and high permeability values (24.6 mm h−1) in the sub-surface soil layers, and produced an average soil loss of 19.7 g m−2 and average runoff coefficients of 26.1%. Statistical analyses showed that: i) the generation of runoff was closely correlated with soil loss; and, ii) an increase in the vegetation cover helped reduce soil erosion. In comparison to larger areas such as a catchment, the pedon scale produced lower or similar soil losses and runoff coefficients in rainfall simulation conditions, although the influence of vegetation cover as a control factor was also detected.

It is well known that rainfall causes soil erosion in sloping German vineyards, but little is known about the effect of age of plantation on soil erosion, which is relevant to understand and design sustainable management systems. In the Ruwer-Mosel valley, young (1- to 4-years) and old (35- to 38-years after the plantation) vineyards were selected to assess soil and water losses by using two-paired Gerlach troughs over three years (2013-2015). In the young vineyard, the overland flow was 107 L m-1 and soil loss 1000 g m-1 in the year of the plantation, and decreased drastically over the two subsequent years (19 L m-1; 428 g m-1). In the old vineyard, soil (from 1081 g m-1 to 1308 g m-1) and water (from 67 L m-1 to 102 L m-1) losses were 1.2 and 1.63 times higher, respectively, than in the young vineyard.

German vineyards are one of the land uses most prone to soil erosion. Due to their placement on mainly steep slopes and non-conservative cultivation practices, runoff and soil loss are a serious problem for wine growers. In the Saar-Mosel valley (Rhineland-Palatinate, Germany), there is a tendency towards organic management of vineyards with protective grass cover in the inter-rows. Since there is a lack of information about organic-conventional tillage in German vineyards related to soil erosion processes, this study presents a comparison between these two soil management practices. For this purpose, 22 rainfall simulations were performed as well as a medium-term monitoring by using 4-paired Gerlach troughs in two experimental sites in the Saar-Mosel valley. The mean simulated runoff coefficient and suspended sediment load in conventional vineyards amounted up to 23.3% and 33.75 g m -2 , respectively. In the organic site, runoff and soil loss were only recorded in one out of the 11 simulations. Runoff and sediment was collected in the Gerlach troughs for 33 natural rainfall events. In the conventional vineyard, the total measured soil loss was 3314.63 g m -1 and 6503.77 g m -1 and total runoff volumes were 105.52 L m -1 and 172.58 L m -1 . In the organic site, total soil losses reached 143.16 g m -1 and 258.89 g m -1 and total runoff was 21.65 L m -1 and 12.69 L m -1 . When soil loss was measured without corresponding runoff or precipitation, soil erosion was activated by tillage or trampling. Finally, the conventional vineyard showed a higher variability in soil loss and runoff suggesting less predictable results.

Conventional Mediterranean vineyards from the Montes de Malaga (Axarquia region, Spain) are characterized by high average temperatures, extreme rainfall events during autumn and winter, elevated stoniness and steep slopes (20–50°). Traditionally, several problems of high soil loss, rill and ephemeral gully generation, and elevated runoff are observed by farmers, which are increasing land degradation processes and a decrease of the productivity. According to this, the main aims of this paper were: i) to quantify the initial soil loss, surface flow and infiltration processes; ii) to characterize and describe the hydrological and geomorphological dynamics; iii) to detect the key factors, which control the soil erosion processes. For this purpose, a combined methodology was applied, using soil analysis, a small portable rainfall simulator and a Guelph permeameter on one experimental plot cultivated with vineyards with steep slopes. Results showed a high variability of soil erosion and permeability processes. Soil analysis showed an elevated concentration of silt particles and stoniness, with higher contents of sand particles between 0 and 5 cm, and clays from 5 cm. With a Guelph permeameter, high average of permeability and saturated hydraulic conductivity with elevated standard deviation were observed. Furthermore, an increase of these parameters from the upper to the foot slope was registered. By using rainfall simulations, on the upper and the foot slope positions the highest runoff coefficient and soil loss were registered. The most elevated peak of sediment concentration was obtained on the middle slope. In general, high infiltration coefficients between 66.5 and 100% were observed. In conclusion it was observed that the activation of the soil erosion processes was due to the distribution of the surface soil components (high roughness, several cracks and high stoniness and silt content), the steep slopes and the impact of the soil traditional tillage practices. These Mediterranean hillslope vineyards registered a mixed Hortonian-Hewlettian model, which combines surface and sub-surface flow conditioned by the micro-topographical changes and its saturation degree.

Knowledge about connectivity and what affects it, through space and time, is needed for taking appropriate action at the right place and/or time by stakeholders. Various conceptual frameworks for hydrological and sediment connectivity have been developed in recent years. For most of these frameworks, the objective was to conceptualise connectivity, not necessarily to infer it from measurements. Studies focussing on measurements of connectivity have so far not been done often. Because of lack of data on connectivity, few real-world data have been used in recent connectivity modelling studies. The aim of this study was to demonstrate that existing data can be used to assess governing factors of connectivity, and how these change over time. Data from three catchments in Navarre, Northern Spain, were used to assess factors that influence hydrologic and sediment connectivity. These factors were used as components in a linear model for discharge and suspended-sediment yield. Three components of connectivity were distinguished: topographical, biological and soil. Changes in the topographical component for the studied periods were considered relatively small, and, therefore, kept constant. Changes in the biological component were determined using the Normalised Difference Vegetation Index. Changes in the soil component were assessed using an Antecedent Precipitation Index. Nash–Sutcliffe model efficiency coefficients were between 0·49 through 0·62 for the discharge models and between 0·23 through 0·3 for the sediment-yield models. We recommend applying the model at smaller spatial scales than catchment scale to minimise the lumping of spatial variability in the components. Copyright © 2016 John Wiley & Sons, Ltd.

In spring 2009, four rill experiments were accomplished on a fallow land. Most external factors as well as discharge quantity (9 L min-1) were held constant or at least in the same range. Following most process based soil erosion models, detachment or runoff values should therefore be similar, but the experimental results show clear differences in sediment concentration, runoff and other measured and calculated values. This fact underlines the problems of process based models: concerning rill erosion, different processes take part and the process described by the models is only responsible for a part of the eroded material.

For a long time, studies concerning erosion caused by concentrated overland flow mainly dealt with the erosion and the transport of fine material. More recent studies have shown that rock fragments reduce the intensity of soil erosion processes on the one hand, but on the other hand rock fragment movements also have been observed both in the rill- and interrill erosion processes. However, there is little knowledge about the movement process of rock fragments in shallow channel flow. Are certain movement patterns typical for different shapes? Are there relationships between movement patterns and slope and flow velocity? Are all these patterns and relationships reproducible? To answer these questions, we performed laboratory channel experiments. With these experiments, we could obtain information about movement patterns of pebbles, by varying the following parameters: shape (flat, ellipsoidal, nearly spherical), size (diameter between 1.97 and 4.0 cm) and channel slope (5°, 10°). During the experiments, a high-speed camera was used to capture the motion of eight specially painted pebbles. The resulting image sequences were processed using both automatic image processing and manual visual inspection. Besides the movement patterns, the pebbles velocity, the water velocity and the water depth were estimated. We could show that there were different movement patterns depending on the shape and the slope. For the 5° experiments, the big, flat pebbles lie at the beginning of the tests. After the following yawing, the pebbles mainly showed the movement form rolling around the longest axis. For the 10° experiments the big, flat pebbles showed the same movement pattern firstly, but later in the sequence, they started to roll around their shortest axis and in the end this movement form was combined with saltation. These patterns are described using a simple symbolic language: sequences of pictograms describe the consecutive movement forms. Furthermore, we detected five different velocity groups of the pebbles for each slope: different cross-section shapes of the pebbles result in different acceleration behavior. The methodology is limited to clear water in laboratory use. Even a larger water depth restricts the image processing. Thus, in the future the experiments will be combined with a small sensor that is implanted in the pebbles and measures forces (acceleration), compass (magnetic flux density) and rotations (gyroscope).

The set-up and characterisation of an indoor nozzle-type rainfall simulator (RS) at Wageningen University, the Netherlands, are presented. It is equipped with four Lechler nozzles (two nr. 460·788 and two nr. 461·008). The tilting irrigation plot is 6 m long and 2·5 m wide. An electrical pump supplies the constant flow during the experiments. The spatial distribution of the rainfall was measured with 60 rain gauges equally distributed on the experimental plot. Thies® Laser Precipitation Monitor was used to measure the size and falling velocity of the raindrops. Four different flow rates were applied (Q1–4). From the collected data, spatial rainfall intensity and spatial kinetic energy distribution maps were created; Christiansen uniformity coefficient was calculated for each flow rate. The results of the experiments revealed that the rainfall parameters (spatial rainfall intensity, kinetic energy, raindrop size distribution and fall velocity) in the RS are not homogeneous (Christiansen uniformity ranges from 68·5% to 83·2%). Accordingly, the whole plot can only be irrigated irregularly applying a wide range of intensities and rainfall energies. The RS offers a good opportunity to study great variety of process intensities such as splash erosion, runoff generation, soil aggregate stability, organic matter migration and scaled landscape development.

The Mosel Wine region has suffered during the last decades a decrease in productive area, mostly on steep sloping vineyards. To avoid the spread of diseases, the extraction of grapevines on abandoned vineyards is mandatory in Rhineland-Palatinate. At the same time, the organic production of wine is growing slowly, but well established in the area. We assess in this paper the degree of the land-use changes, as well as their effect on runoff generation and sediment production, depending on the age of the abandonment, as well as the type and age of the land management, whether organic or conventional. Land use data were obtained to identify land-use change dynamics. For assessment of runoff generation and soil erosion, we applied rainfall simulation experiments on the different types of vineyard management. These were organically managed, conventionally managed and abandoned ones, all of varying ages. During the last decades of the last century, a decrease of around 30% of vineyard surface could be observed in Germany&rsquo, s Mosel Wine Region, affecting mostly the steep sloping vineyards. Despite a high variability within the types of vineyard management, the results show higher runoff generation, and soil erosion associated with recently installed or abandoned vineyards when compared to organic management of the vineyards, where erosion reached only 12%. In organic management, runoff and erosion are also reduced considerably, less than 16%, after a decade or more. Thus, organic vineyard management practices show to be very efficient for reduction of runoff and erosion. Consequently, we recommend to adopt as far as possible these soil management practices for sustainable land management of steep sloping vineyards. In addition, soil protection measures are highly recommended for vineyard abandonment according to the law.

The relative impact of water and wind on total erosion was investigated by means of an experimental-empirical study. Wind erosion and water erosion were measured at five different sites: (1) Mediterranean fallow, (2) Mediterranean orchard, (3) wheat field, (4) vineyard and (5) sand substrate. Mean erosion rates ranged from 1.55 to 618 g&middot, m&minus, 2&middot, h&minus, 1 for wind and from 0.09 to 133.90 g&middot, 1 for rain eroded material over all tested sites. Percentages (%) of eroded sediment for wind and rain, respectively, were found to be 2:98 on Mediterranean fallow, 11:89 on Mediterranean orchard, 3:97 on wheat field, 98:2 on vineyard and 99:1 on sand substrate. For the special case of soil surface crust destroyed by goat trampling, the measured values emphasize a strong potential impact of herding on total soil erosion. All sites produced erosion by wind and rain, and relations show that both erosive forces may have an impact on total soil erosion depending on site characteristics. The results indicate a strong need to focus on both wind and water erosion particularly concerning soils and substrates in vulnerable environments. Measured rates show a general potential erosion depending on recent developments of land use and climate change and may raise awareness of scientist, farmers and decision makers about potential impact of both erosive forces. Knowledge about exact relationship is key for an adapted land use management, which has great potential to mitigate degradation processes related to climate change.

In the framework of the EU-INTERREG-IVb-project ForeStClim (Transnational Forestry Management Strategies in Response to Regional Climate Change Impacts) a combination of experimental methods has been applied for the investigation of the spatial and temporal variation and intensity of overland flow generation and soil erosion processes. In the presented study, the influences of land-use type and land-management practices on overland flow generation and soil erosion are investigated for three low mountain range catchments in Luxembourg and in Rhineland-Palatinate, Germany. The key questions of the study can be summarized as follows: Can Hortonian overland flow generation be observed on all land-use types in the investigated areas in the Central European low mountain range? How can the contribution of forested areas to the flood and erosion dynamics be evaluated under humid climate conditions in Central Europe and what are the most important factors of influence? The results of the presented study show that forest areas can also be sources for overland flow and sediment, particularly artificial linear structures like unpaved roads and harvester tracks, where runoff coefficients between 41.2 and 97.1%, and erosion values between 2.6 and 122.5 g m− 2 were determined using rainfall experiments. Another important factor is soil water repellency, this factor can pre-eminently be observed under rather dry soil moisture conditions in summer and can have severe influence on overland flow generation particularly in forested areas. The results of the rainfall experiments in coniferous forests show runoff coefficients ranging from 0 to 86.9%, here the high values can all be traced back to water repellency influence, as the field observations suggest. In the context of flood generation, it is becoming more and more important to improve knowledge on overland flow generation and soil erosion processes occurring in forested catchments, particularly considering the expected climate change.

Fire is a natural factor of landscape evolution in Mediterranean ecosystems. The middle Ebro Valley has extreme aridity, which results in a low plant cover and high soil erodibility, especially on gypseous substrates. The aim of this research is to analyze the effects of moderate heating on physical and chemical soil properties, mineralogical composition and susceptibility to splash erosion. Topsoil samples (15 cm depth) were taken in the Remolinos mountain slopes (Ebro Valley, NE Spain) from two soil types: Leptic Gypsisol (LP) in a convex slope and Haplic Gypsisol (GY) in a concave slope. To assess the heating effects on the mineralogy we burned the soils at 105 and 205 °C in an oven and to assess the splash effects we used a rainfall simulator under laboratory conditions using undisturbed topsoil subsamples (0–5 cm depth of Ah horizon). LP soil has lower soil organic matter (SOM) and soil aggregate stability (SAS) and higher gypsum content than GY soil. Gypsum and dolomite are the main minerals (>80%) in the LP soil, while gypsum, dolomite, calcite and quartz have similar proportions in GY soil. Clay minerals (kaolinite and illite) are scarce in both soils. Heating at 105 °C has no effect on soil mineralogy. However, heating to 205 °C transforms gypsum to bassanite, increases significantly the soil salinity (EC) in both soil units (LP and GY) and decreases pH only in GY soil. Despite differences in the content of organic matter and structural stability, both soils show no significant differences (P < 0.01) in the splash erosion rates. The size of pores is reduced by heating, as derived from variations in soil water retention capacity.

28 páginas, 6 figuras, 2 tablas.- The definitive version is available on: http://www.sciencedirect.com/science/article/pii/S0341816213001252, [EN] Small-scale portable rainfall simulators are an essential research tool for investigating the process dynamics of soil erosion and surface hydrology. There is no standardisation of rainfall simulation and such rainfall simulators differ in design, rainfall intensities, rain spectra and research questions, which impede drawing a meaningful comparison between results. Nevertheless, these data become progressively important for soil erosion assessment and therefore, the basis for decision-makers in application-oriented erosion protection. The artificially generated rainfall of the simulators used at the Universities Basel, La Rioja, Malaga, Trier, Tübingen, Valencia, Wageningen, Zaragoza, and at different CSIC (Spanish Scientific Research Council) institutes (Almeria, Cordoba, Granada, Murcia and Zaragoza) was measured with the same methods (Laser Precipitation Monitor for drop spectra and rain collectors for spatial distribution). Data are very beneficial for improvements of simulators and comparison of simulators and results. Furthermore, they can be used for comparative studies, e.g. with measured natural rainfall spectra. A broad range of rainfall data was measured (e.g. intensity: 37–360 mm h− 1; Christiansen Coefficient for spatial rainfall distribution: 61–98%; median volumetric drop diameter: 0.375–6.5 mm; mean kinetic energy expenditure: 25–1322 J m− 2 h− 1; mean kinetic energy per unit area and unit depth of rainfall: 0.77–50 J m− 2 mm− 1). Similarities among the simulators could be found e.g. concerning drop size distributions (maximum drop numbers are reached within the smallest drop classes < 1 mm) and low fall velocities of bigger drops due to a general physical restriction. The comparison represents a good data-base for improvements and provides a consistent picture of the different parameters of the simulators that were tested., The research for this study was funded by the Deutsche Forschungsgemeinschaft (DFG) project number Ri-835/6-1. We would like to thank the anonymous reviewers for their remarks.

The results from several rainfall simulations performed on two abandoned fields of different ages in the Central Ebro Depression have been analysed by application of the physically based hydraulic model HILLFLOW 1D. The data gained by the simulations was used to parame - terise the model. Afterwards, the runoff generation characteristics were determined by simulation of different rainfall intensities and different macroporosities of the soil. The young fallow land shows a minimum inten - sity for runoff generation of 6 mm h-1. An increase of the rainfall intensity leads rapidly to a growing runoff coefficient, being the value modelled for 30 mm h-1 nearly the same as the simulated one (40 mm h-1). Another con - clusion of the simulations and their modelling is the homogeneity of the soils on the young fallow land, with no macroporosity all over the profile. On the other hand, the rainfall simulations and the modelling on the old fallow land show a high variability of rainfall-runo ff response patterns, strongly conditioned by the presence of macropores. They are distributed very irregularly throughout the soil of the old fallow land. In both cases, water infiltrates only little into the soil matrix, for that measures for enhan- cing soil hydraulic properties are needed. RESUMEN: Se han analizado los resultados de numerosas simulacio - nes de lluvia en campos abandonados de diferente antuguedad en la Depresion central del Ebro aplicando el modelo hidrologico de base fisi ca HILLFLOW 1D. Los datos de las simulaciones se utilizaron para para - metrizar el modelo. A continuacion, las caracteristicas de la generacion de escorrentia se analizaron modelizando diferentes intensidades de lluvia y volumenes de macroporos en el suelo. En el campo recientemente aban - donado se pudo calcular una intensidad de llluvia minima para la gene- racion de escor rentia de 6 mm h-1. Una intensidad de precipitacion cr e - ciente produce un incremento muy fuerte del coeficiente de escor rentia, de modo que precipitaciones de 30 mm h-1 se diferencian poco de las simu- ladas con 40 mm h-1. Otra conclusion es que los suelos del campo recien - temente abandonado son muy homogeneos y estan caracterizados por la ausencia de macroporos. La respuesta de la generacion de escor rentia a la precipitacion es en cambio muy variable en el campo abandonado anti

The present paper is based on several field investigations (monitoring soil and rill erosion by aerial photography, rainfall simulations with portable rainfall simulators, and manmade rill flooding) in southern Spain. Experiments lead now to a closer understanding of the dynamics and power of different soil erosion processes in a gully catchment area. The test site Freila (Andalusia, Spain) covers an area of 10.01 ha with a rill density of 169 m ha−1, corresponding to a total rill length of 1694 m. Assuming an average rill width of 0.15 m, the total rill surface can be calculated at 250 m2 (0.025 ha). Given that, the surface covered by rills makes up only 0.25% of the total test site. Since the rill network drains 1.98 ha, 20% of the total runoff comes from rills. The rills’ sediment erosion was measured and the total soil loss was then calculated for detachment rates between 1685 g m−2 and 3018 g m−2. The interrill areas (99.75% of the test site) show values between 29 and 143 g m−2. This suggests an important role of rill erosion concerning runoff and soil detachment.

The importance of distinguishing and discretely studying the subprocesses of runoff generation and erosion has led to the development of rainfall simulations on small plots. We methodically upgraded a small portable rainfall simulator with particular respect to (1) rainfall characteristics that include homogeneous spatial rainfall distribution and drop spectrum, (2) handling, and (3) control of test conditions. We measured simulator characteristics with rain gauges, calibration plate and Laser Precipitation Monitor by Thies (LPM). The upgraded small rainfall simulator, and measurements of the improved rainfall characteristics are presented in this paper.The upgraded configuration shows the desired improvements: regarding drop size distribution, a close relationship to natural rainfall (Marshall & Palmer Distribution) can be observed. Due to low fall heights, measured drop fall velocities are slow; maximum velocities range between 3.4 and 5 m s1. Mean kinetic energy expenditure, mean kinetic energy per unit area and unit depth of rainfall and mean momentum are 214 J m2 h1, 5.8 J m2 mm1 and 0.016 kg m s1, respectively. The spatial rainfall distribution of the upgraded simulator is homogenous with a Christiansen-Uniformity Coefficient of 91%. The measured variables show extremely low variation throughout all tests and should therefore be reproducible in field investigations at any time.

Within this paper a standardized method to quantify sediment transport and runoff in natural rills is described. In order to achieve this, several rill experiments (RE) were accomplished in March 2007 in the Arnás catchment in the Spanish Pyrenees. Both, anthropogenically initiated and naturally developed rills were flushed with a total water quantity of 72 l in 8 minutes (equivalent to 9 l min-1). For the characterisation of the rill, slope is measured and micromorphological features like scours are registered. The experiments are characterised by the flow velocities along the whole flushed rill, sediment concentrations at different points and different times during the experiment. Runoff is measured after 25 m continuously. With this data, a set of characteristic variables is generated, which reflects the infiltration and flow behaviour along the rill. By means of rainfall simulations within the rills catchments, their contributing runoff was estimated also. The tested rills were developed on average slopes oscillating between 7.6° and 11.3°, the steepest slope reached 16°. The sediment concentrations reached average values between 0.69 and 2.21 g l-1, the maximum values ranged between 1.59 and 6.31 g l-1. Comparing the sediment concentrations measured in the rills to the sediment concentrations in the runoff of the river Arnás, it can be stated that the concentrations in the rills are usually higher. Though, the runoff was to low to cause erosion. Accordingly, the runoff amount that can be produced within the rills catchments was found to be about 10-25 times higher. By means of the developed rill experiments, for which easy to handle devices were built and are described in detail, it becomes possible to assess the effectivity of individual rills in a catchment and to evaluate their hydraulic functioning as well as their geomorphodynamic activity

The Pyrenean and Pre-Pyrenean mountain areas have been intensively used at least since roman times, but nowadays depopulation has lead to widespread land abandonment without a steering land-management. Vegetation recovery is weak in most abandoned fields. Soil formation and characteristics are conditioned by this fact, and for this, soils show past degradation processes and are mostly predominant factors for continuing land degradation or restoration. Three study areas were set up along a climatic gradient with increasing summer water deficit in the sub-humid zone between the Central Pyrenees and Pre-Pyrenees. Soil survey combined with experiments for the determination of infiltration, runoff and erosion were applied for understanding the degradation history and the future development of the soils. All areas are dominated by Entisols, but also Inceptisols and Alfisols are found, and even soils with hydromorphic features. The soils show signs of heavy erosion. The parental material determines the nutrient supply and the general chemical properties. All sites show a weak water storing capacity, as a result of the removal of fine material by erosion and due to the depletion of soil organic matter. In addition, infiltration capacity and runoff generation are high within the studied areas, averaging between 27 and 37 per cent. The driest area studied shows an ongoing trend to degradation, with high erosion rates combined with a high degradations status of the soil. The other areas are characterised by a patchy pattern of soil degradation and regradation processes. Copyright © 2008 John Wiley & Sons, Ltd.

The aim of this study was to enable a quantitative comparison of initial soil erosion processes in European vineyards using the same methodology and equipment. The study was conducted in four viticultural areas with different characteristics (Valencia and Málaga in Spain, Ruwer-Mosel valley and Saar-Mosel valley in Germany). Old and young vineyards, with conventional and ecological planting and management systems were compared. The same portable rainfall simulator with identical rainfall intensity (40 mm h− 1) and sampling intervals (30 min of test duration, collecting the samples at 5-min-intervals) was used over a circular test plot with 0.28 m2. The results of 83 simulations have been analysed and correlation coefficients were calculated for each study area to identify the relationship between environmental plot characteristics, soil texture, soil erosion, runoff and infiltration. The results allow for identification of the main factors related to soil properties, topography and management, which control soil erosion processes in vineyards. The most important factors influencing soil erosion and runoff were the vegetation cover for the ecological German vineyards (with 97.6 ± 8% infiltration coefficients) and stone cover, soil moisture and slope steepness for the conventional land uses.

Small portable rainfall simulators are considered a useful tool to analyze soil erosion processes in cultivated lands. European research groups in Spain (Valencia, Málaga, Lleida, Madrid and La Rioja), France (Reims) and Germany (Trier) have used different rainfall simulators (varying in drop size distribution and fall velocities, kinetic energy, plot forms and sizes, and field of application) to study soil loss, surface flow, runoff and infiltration coefficients in different experimental plots (Valencia, Montes de Málaga, Penedès, Campo Real and La Rioja in Spain, Champagne in France and Mosel-Ruwer valley in Germany). The measurements and experiments developed by these research teams give an overview of the variety of methodologies used in rainfall simulations to study the problem of soil erosion and describe the erosion features in different climatic environments, management practices and soil types. The aims of this study are: (i) to investigate where, how and why researchers from different wine-growing regions applied rainfall simulations with successful results as a tool to measure soil erosion processes; (ii) to make a qualitative comparison about the general soil erosion processes in European terroirs; (iii) to demonstrate the importance of the development of standard method for measurement of soil erosion processes in vineyards, using rainfall simulators; and (iv) and to analyze the key factors that should be taken into account to carry out rainfall simulations. The rainfall simulations in all cases allowed infiltration capacity, susceptibility of the soil to detachment and generation of sediment loads to runoff to be determined. Despite using small plots, the experiments were useful to analyze the influence of soil cover to reduce soil erosion, to make comparisons between different locations, and to evaluate the influence of different soil characteristics. The comparative analysis of the studies performed in different study areas points out the need to define an operational methodology to carry out rainfall simulations, which allows us to obtain representative and comparable results and to avoid errors in the interpretation in order to achieve comparable information about runoff and soil loss., We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)., We acknowledge all the co-authors for the fast and friendly response to take part in this paper and their useful suggestions and corrections. Furthermore, we also thank the Caixa-Bank and DAAD (Deutscher Akademischer Austauschdienst) for the Scholarship grant awarded to J. Rodrigo-Comino.

Steep slopes, erodible soils, rill and ephemeral gullies, compaction due to wheel. traffic and human trampling are common features in vineyards around the world and result in high soil erosion rates. However, little is known about seasonal and spatial variations of soil erosion rates due to factors such as the impact of the vine plantation, harvest, and tillage on the soil redistribution over the long-term temporal scale. The goal of this study is to assess long-term soil erosion rates and the impact of management on sediment and runoff yield by means of Gerlach troughs and a topographical approach based on botanic benchmarks in two paired vineyards with different ages (3 and 35 years) located on the hillslope of the Ruwer-Mosel Valley (Germany). We studied: i) soil profiles and properties at different hillslope locations and ii) soil redistribution and erosion by means of topsoil level maps applying botanic benchmarks using the Stock Unearthing Method (SUM), RUSLE (Revised Unviersal Soil Loss Equation) and Gerlach troughs. The SUM showed that the old vineyard's erosion rates ranged from 3.3 to 3.8 Mg ha(-1) yr(-1), which was similar to the Gerlach trough measurements, and we demonstrated that the soil erosion rates depended on rainfall characteristics and human disturbances due to tillage, harvest trampling, and compaction by heavy machinery. Data from the SUM in the young vineyard showed 62.5 Mg ha(-1) yr(-1) of soil loss, which is a consequence of severe soil disturbance during the planting of the new vineyard. Finally, to prove the reliability data, RUSLE showed higher soil loss in the young vineyards (19.46 Mg ha(-1) yr(-1)) than in the old ones (11.28 Mg ha(-1) yr(-1)).

Rainfall simulations at different scales have been used for understanding the influence of different factors on runoff generation and erosion. They are an accepted method for calibrating and validating physically based rainfall and erosion models. Nevertheless, it is proven that not only the patterns of rainfall are highly variable over space and time. Soil parameters responsible for runoff generation and erosion – e.g. infiltration capacity, soil moisture, aggregate stability – are highly variable, too. The results of more than 100 plot scale rainfall simulations on abandoned fields in different areas of Spain are analysed for identifying and quantifying factors affecting runoff and erosion processes. The variability of superficial runoff and suspended sediment yield is very high within most of the test areas, reaching values up to a runoff coefficient of 1 and yielding 130 g per experiment. Only within the semi-arid areas we can find a significant and high correlation between vegetation cover and sediment yield (and sediment concentration), whereas most of the other investigated surface parameters show no influence on runoff and erosion. For this, even in simulations on small plots more complex processes can be assumed. The factors controlling them have to be searched, even at detailed scales, within the geo-ecological characteristics of the investigated areas at chorological scales.

Vineyards are one of the most German conditioned eco-geomorphological systems by human activity. Precisely, the vineyards of the Ruwer Valley (Germany) is characterized by high soil erosion rates and rill problems on steep slopes (between 23–26°) caused by the increasingly frequent heavy rainfall events, what is sometimes enhanced by incorrect land use managements. Soil tillage before and after vintage, application of vine training systems and anthropic rills generated by wheel tracks and footsteps are observed along these cultivated area. The objective of this paper is to determine and to quantify the hydrological and erosive phenomena in two chosen vineyards, during diverse seasons and under different management conditions (before, during and after vintage). For this purpose, a combined methodology was applied. Investigating climatic, pedological, geomorphological and botanic-marks variables was suggested on the two experimental plot in the village of Waldrach (Trier, region of Rhineland-Palatinate). First, high infiltration rates (near 100%) and subsurface flow was detected by rainfall simulations performed at different times of the year. The second method to investigate the geomorphological response of slope inclination, two 10 m and one 30 m long rills were measured using geometrical channel cross-section index, depth and width. The highest variations (lateral and frontal movements) were noted before and during vintage, when footsteps occurred in a concentrated short time. Finally, two maps were generated of soil loss, indicated by the botanic marks on the graft union of the vines. As results 62.5 t−1 ha−1 yr−1 soil loss rate was registered (one year) on the experimental plots of the new vineyards, while 4.3 t−1 ha−1 yr−1 on the old one.

Fire is a natural factor of landscape evolution in Mediterranean ecosystems. Middle Ebro Valley has extreme aridity, which determines a low plant cover and high soil erodibility of the soils, especially on gypseous substrates. The aim of this research is to analyze the effects of a moderate heating, on physical and chemical soil properties, mineralogical composition and susceptibility to splash erosion. Topsoil samples (15 cm soil depth) were taken in the Remolinos mountain slopes (Ebro Valley, NE-Spain) from two soil types: Leptic Gypsisol (LP) in a convex slope and Haplic Gypsisol (GY) in a concave slope. To assess the heating effects on the mineralogy we burned the soils at 105 °C and 205 °C in an oven and to assess the splash effects we used a rainfall simulator under laboratory conditions using undisturbed topsoil subsamples (0–5 cm soil depth of Ah horizon). LP soil has lower SOM and SAS and higher gypsum content than GY soil. Gypsum and dolomite are the main minerals (>80%) in the LP soil, while gypsum, dolomite, calcite and quartz have similar proportions in GY soil. Clay minerals (kaolinite and illite) are scarce in both soils. Heating at 105 °C has no effect on soil mineralogy. However heating to 205 °C transforms gypsum to bassanite, increases significantly EC in both soil units (LP and GY) and decreases pH only in GY soil. Despite differences in the content of organic matter and structural stability, both soils show no significant differences (P < 0.01) in the splash erosion rates. The size of pores is reduced by heating treatment or fire effect, as derived from variations in pF.

Recent research has shown that wind can have a signififi cant inflfl uence on velocity, impact angle and kinetic energy of raindrops, and subsequently increases soil erosion. The aims of this study were to 1) quantify the inflfl uence of wind on water erosion, 2) specififi cally observe the difference in processes betweenwindless rain (WLR) and wind-driven rain (WDR) simulations and 3) test the device’s and test sequence’s practicability. The Portable Wind and Rainfall Simulator (PWRS), recently developed at Trier University for plot-scale in situ assessment of differences in soil erosion with and without the inflfl uence of wind on raindrops, wasused. To facilitate extraction of the inflfl uences of WDR on soil erosion, to avoid systematic errors, and to reduce variability between test plots, a defifi ned order of four consecutive test runs was established: 0) wind simulation, 1) WLR simulation on dry soil, 2) WLR simulation on moist soil, 3) WDR simulation. The tests were conducted on homogenous sandy substrate deposited on an area of 15.2 m 60 m with uniform and smooth surface and low inclination (1°) in the Willem Genet Tunnel of Wageningen University. The results show an increase of eroded sediment ranging from 113 % up to 1108 % for WDR simulations in comparisonto WLR simulations. The increase in runoff was considerably lower (15 % to 71 %), resulting in an increase of sediment concentration between 56 % and 894 %. The results indicate an immense impact of WDR on soil erosion of sandy cohesionless substrate. The experimental setting and measurement proved reliable and reproducible and enables a clear process observation and quantififi cation in the fifi eld.

To assess the inflfl uence of rainfall simulator type and plot dimensions on runoff and erosion, seven small portable rainfall simulators from Freiberg, Tubingen, Trier (all Germany), Valencia, Zaragoza (both Spain), Basel (Switzerland) and Wageningen (the Netherlands) were compared on a prepared bare fallow fifi eld. The experiments were carried out during an international rainfall simulator workshop, organized at Trier University (Germany) from 30th of June to 1st of July 2011.The tested rainfall simulators differ in design, rainfall intensities, rain spectra, etc. and represent most of the devices which have been used over the last decade in Europe. The plots for the different rainfall simulators were selected as similar as possible concerning soil physical and chemical properties, aspect and inclination and were chosen to be placed side by side in horizontal direction. Test procedure was standardized in order to examine the inflfl uence of the rainfall simulator andplot dimension only. The results show a clear and consistent relationship in runoff, erosion and infifi ltration behaviour of the different used rainfall simulators. With all the devices total soil loss is measurable, but different plot sizes, intensities and kinetic energies of the simulated rainfall caused differences in soil loss and runoff quantities per unit of area. Regarding course characteristics over runs, similarities could be observed especially in runoff behaviour. The rainfall simulators (> 1 m² plot size) are able to reproduce infifi ltration and interrillerosion processes. With an increase of plot size (≥ 1 m²), rill-erosion will be also reflfl ected. Therefore it can be concluded that up to a certain plot size, the results of the different simulators are comparable and depend in their magnitude on the properties of the applied rainfall. The increase in process complexity with increasing plot size shows, that the scale of the simulation is one of the most important parameters to be taken intoaccount when comparing values of erosion and runoff.

The state of river channels and their riparian zones in terms of geomorphology and vegetation has a significant effect on water and sediment transport in headwater catchments. High roughness in natural rivers due to vegetation and geomorphological attributes generate drag on flowing water. This drag will slow water discharge, which in turn influences the sediment dynamics of the flow. The impacts of changes in the management of rivers and their riparian zone (either by catchment managers or river restoration plans) impacts both up- as well as downstream reaches, and should be assessed holistically prior to the implementation of these plans.To assess the river's current state as well as any possible changes in geomorphology and vegetation in and around the river, effective approaches to characterise the river are needed. In this paper, we present a practical approach for making detailed surveys of relevant river attributes. This methodology has the benefit of being both detailed – describing river depth, width, channel morphology, erosive features and vegetation types – but also being practical in terms of time management. This is accomplished by identifying and describing characteristic benchmark reaches (typical sites) in detail against which the remainder of the river course can be rated. Using this method, a large river stretch can be assessed in a relatively short period while still retrieving high quality data for the total river course. In this way, models with high data requirements for assessing the condition of a river course, can be parameterised without major investments on field surveys.In a small headwater catchment (23 km2) in southwestern Poland, this field methodology was used to retrieve data to run an existing model (HEC-GeoRAS) which can assess the impact of changes in the riparian and channel vegetation and channel management on sedimentation processes and stream flow velocity. This model determines the impact of channel morphology and in-channel and riparian vegetation on stream flow and sediment transport. Using four return periods of flooding (2, 10, 20 and 100 years), two opposing channel management / morphology scenarios were run; a natural channel and a fully regulated channel. The modelling results show an increase in the effect of riparian vegetation / geomorphology with an increase in return period of the modeled peak discharge. More natural channel form and increased roughness reduces the stream flow velocity due to increasing drag from flow obstructions (vegetation and channel morphological features). The higher the flood water stage, the greater the drag due to vegetation on the floodplains of natural river reaches compared to channelised sections. Slower flow rates have an impact on sediment mobilisation and transport in the river.

In this study two approaches are presented to identify Dominant Runoff Processes (DRP) with respect to regionalization. The approaches are a simplification of an existing method to determine DRP by means of an extensive field campaign. The first approach combines the permeability of the substratum, land-use and slope of the basin in a GIS-based analysis. The second approach makes use of discriminant analysis of the physiographic characteristics of the basin and links it to the GIS analysis. The results of the developed approaches are maps, which identify dominant runoff processes and represent a spatial distribution of the hydrological behaviour of the soil during prolonged rainfall events. The approaches have been developed in a micro-scale basin (Germany). An additional meso-scale basin was introduced in which the two approaches were applied for quality control. The thus generated maps for the micro-scale basin were compared with an existing DRP map, which was derived with the existing method. The first approach showed a resemblance of 79% when compared to this map, whereas the second approach showed only a resemblance of 51%. The generated maps for the meso-scale basin were compared to DRP that were determined point wise according to the existing method. The first approach showed in this case a resemblance of 81%, whereas the second approach showed a resemblance of 68%. Therefore, the first approach is preferred to the second approach when accuracy, data input and calculation time are concerned.

Rainfall simulation is a widely used method for soil erosion studies on agricultural land. Major problem of this experimental research method is the comparability between different simulators due to differences in simulated rainfall. Therefore the purpose of this study is to characterize the rainfall produced by a rainfall simulator which was widely used during the last decades. Four different calibration methods were used to assess the drop size distribution: (1) Indication Paper, (2) Plaster Micro Plot, (3) Joss–Waldvogel Disdrometer and (4) Laser Distrometer (Thies). Additionally, the latter one was used to measure drop fall velocity in combination with drop diameter. The spatial rainfall distribution pattern on the plot was measured with 100 rainfall gauges. The spatial rainfall distribution pattern clearly shows a heterogeneity, which is caused by the used nozzle configuration. Considerable differences in drop-size distribution can be observed depending on the used measurement technique. Laser Disdrometer and Plaster Micro Plot cover the whole produced drop size spectrum ranging from 3.0 mm, whereas Indication Paper as well as the Joss–Waldvogel Disdrometer primarily show drops smaller than 2.0 mm. Characterisation of rainfall is therefore strongly dependent on the used method and if different methods are used, may lead to contradictory results. The volume drop size distribution reflected by the Laser Distrometer is very similar to that one produced by rain with an intensity of 40 mm h −1 . Nevertheless, with maximum velocities above 10 m s −1 small drops are by far too fast and large drops with velocities dominantly below 5 m s −1 are too slow compared to natural rainfall. As an overall result, the simulator can be characterised as suitable for runoff and infiltration measurements, but with constraints due to the low reproducibility of the spatial rain distribution. As a consequence of the produced drop spectrum and fall velocity the erosion quantities may be underestimated systematically. For this, methodological development has to be focussed on homogeneous spatial rainfall distributions and on increasing the amount of large drops with higher fall velocities.

22 Pag., 3 Tabl., 7 Fig., This paper studies the hydrological response to rainstorm events of a small experimental catchment in the Central Spanish Pyrenees. The Arnás catchment was cultivated until 40 years ago, and then abandoned and affected by plant recolonisation, especially shrubs. A rainfall of a few millimeters is enough to produce a sudden increase in discharge, due most probably to the steep gradients and the small size of the catchment and the extensive areas with low vegetation density and thin soils. The intensity of the response shows a very high variability, depending on the intensity of precipitation and soil humidity conditions before the flood. This paper identifies two types of floods according to the relationships between precipitation and discharge, and confirms that antecedent soil moisture explains much of the response. The shape of the hydrograph, very similar to the hyetograph, suggests that the Arnás catchment is dominated by overland flow processes. However, more intense rainstorms do not generate higher peak flows, thus demonstrating the existence of different runoff-generating areas., This paper has been supported by the following projects: “Water resources management in a changing environment: the impact of sediment on sustainability” (WARMICE, ENV4-CT98-0789) funded by the European Commission; and “Assessment of sediment sources and runoff generation areas in relation to land use changes” (HIDROESCALA, REN2000-1709-C04-01/GLO), “Hydrological processes in seminatural Mediterranean areas” (PROHISEM, REN 2001-2268-C02-01/HID), and “Hydrological processes in Pyrenean catchments in relation to land use and climate changes” (REN 2003-08678/HID), all funded by the CICYT. Monitoring of the catchment has been supported by agreement between the CSIC and the Spanish Ministry of Environment (RESEL).

Las cuencas experimentales de Arnás y San Salvador, localizadas en la cuenca alta del río Aragón, han sido equipadas con estación meteorológica completa, flume e instrumentos para la medición continua del caudal y del sedimentos transportado (en solución y en suspensión). Una trampa de sedimento a la entrada del flume permite controlar periódicamente la carga de fondo. Los resultados obtenidos confirman la existencia de grandes diferencias en la respuesta hidrológica y el transporte de sedimento entre la cuenca forestal (San Salvador) y la cuenca de campos abandonados (Arnás). La primera muestra una respuesta mucho más moderada debido básicamente a los procesos de interceptación y a la mayor profundidad de los suelos. Las relaciones entre precipitación y pico de caudal, así como entre este último y la concentración de sedimento en suspensión son muy bajas, aumentando notablemente si se contemplan por separado las crecidas de estación fría. La escorrentía se genera sobre todo por procesos de saturación. Las fuentes de sedimento se localizan en el cauce y sus proximidades.

Plans to increase the amount of irrigated land in Mediterranean countries should consider how changes in climate and land-use affect water resources. In this study, both precipitation and temperature were used to analyze regional trends in discharge in the basins of the Central Spanish Pyrenees since the mid-20th century. Annual variations in the relationship between precipitation and discharge suggested that discharge was relatively lower in the second half of the study period, coinciding with major changes in land use. On a monthly scale, precipitation increased significantly in October, April, and July, and decreased in March, and temperature increased in January and February and decreased in April. Nevertheless, discharge has decreased significantly in most months in the past 50 years. Land-use and plant-cover changes are the only nonclimatic factor that can explain the loss of around 30% of the average annual discharge., Funding for this research was provided by the following projects: "Water resources management in a changing environment: the impact of sediment in sustainability" (WARMICE, ENV4-CT98-0789), funded by the European Community, and "Assessment of sediment and runoff sources in relation to land-use changes", (HIDROESCALA, REN2000-1709-C04-01/GLO) and "Hydrological processes in semi-natural Mediterranean areas" (PROHISEM, REN2001-2268-C02-01/HID), both funded by CICYT.

27 Pags.- 11 Tabls.- 8 Figs. © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License., In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76 % of the experimental sites with agricultural land use as the dominant type (∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it., First author thanks the International and Scientific Cooperation Office of the University of Maragheh, Iran, as well as the research committee and board members of the university for their assistance in conducting the current work. The financial support received from the Forschungszentrum Jülich GmbH is gratefully acknowledged by the first author. Parts of the database were made available through research work carried out in the framework of LIFE+ projects funded by the EC. The support of the Spanish Ministry of Economy through project CGL2014-53017-C2-1-R is acknowledged. The support of the Czech Science Foundation through project no. 16-05665S is acknowledged. The support of the Slovak Research and Development Agency through project no. APVV-15-0160 is acknowledged.