Effectiveness of cover crops to reduce loss of soil organic matter in a rainfed vineyard
López-Vicente, Manuel ; Calvo-Seas, Elena ; Álvarez, Sara ; Cerdà, Artemi - \ 2020
Land 9 (2020)7. - ISSN 2073-445X
Cover crop - Enrichment ratio - Mediterranean climate - Sediment trap - Soil erosion - Soil organic matter - Vineyard
Cover crops (CCs) minimize the loss of soil in permanent cropping systems where the soil is usually bare due to intense tillage or overuse of herbicides. The topsoil, the richer layer in soil organic carbon and organic matter (OM), is affected by water erosion. Nature-based solutions appear as a suitable option for sustainable farming. In this study, the effectiveness of two years of CC management to reduce the OM loss is evaluated in a rainfed vineyard in a rolling landscape (Huesca, NE Spain). Two sediment traps collected runoff over 15 months. Topsoil OM contents (1.64% and 1.60%) and sediment/soil OM enrichment ratio (2.61 and 3.07) were similar. However, the average annual rate of OM loss was 3.6 times higher in the plot with lower vegetation cover than in the plot with CCs (1.29 vs. 0.35 kgOM ha-1 yr-1). The concentration of OMSed showed a negative relationship with the net soil loss; and significant differences appeared between the OMSed in the months with low and moderate-to-high ground cover. CCs are an excellent nature-based solution to control the unsustainable soil and OM losses measured in vineyards, which will contribute to achieve the Sustainable Development Goals of the United Nations.
Soil erosion along a transect in a forested catchment: Recent or ancient processes?
Calitri, Francesca ; Sommer, Michael ; Meij, Marijn W. van der; Egli, Markus - \ 2020
Catena 194 (2020). - ISSN 0341-8162
239+240 Plutonium - Forest - Moraine landscape - Soil catena - Soil erosion
Forested areas are assumed not to be influenced by erosion processes. However, forest soils of Northern Germany in a hummocky ground moraine landscape can sometimes exhibit a very shallow thickness on crest positions and buried soils on slope positions. The question consequently is: Are these on-going or ancient erosional and depositional processes? Plutonium isotopes act as soil erosion/deposition tracers for recent (last few decades) processes. Here, we quantified the 239+240Pu inventories in a small, forested catchment (ancient forest “Melzower Forst”, deciduous trees), which is characterised by a hummocky terrain including a kettle hole. Soil development depths (depth to C horizon) and 239+240Pu inventories along a catena of sixteen different profiles were determined and correlated to relief parameters. Moreover, we compared different modelling approaches to derive erosion rates from Pu data. We find a strong relationship between soil development depths, distance-to-sink and topography along the catena. Fully developed Retisols (thicknesses > 1 m) in the colluvium overlay old land surfaces as documented by fossil Ah horizons. However, we found no relationship of Pu-based erosion rates to any relief parameter. Instead, 239+240Pu inventories showed a very high local, spatial variability (36–70 Bq m−2). Low annual rainfall, spatially distributed interception and stem flow might explain the high variability of the 239+240Pu inventories, giving rise to a patchy input pattern. Different models resulted in quite similar erosion and deposition rates (max: −5 t ha−1 yr−1 to +7.3 t ha−1 yr−1). Although some rates are rather high, the magnitude of soil erosion and deposition - in terms of soil thickness change - is negligible during the last 55 years. The partially high values are an effect of the patchy Pu deposition on the forest floor. This forest has been protected for at least 240 years. Therefore rather natural events and anthropogenic activities during medieval times or even earlier must have caused the observed soil pattern, which documents strong erosion and deposition processes.
Xanthomonas wilt of banana drives changes in land-use and ecosystem services across infected landscapes
Ocimati, Walter ; Groot, Jeroen J.C. ; Tittonell, Pablo ; Taulya, Godfrey ; Ntamwira, Jules ; Amato, Serge ; Blomme, Guy - \ 2020
Sustainability 12 (2020)8. - ISSN 2071-1050 - p. 1 - 20.
Communities - Disease - Multi-functional - Perceptions - Soil erosion - Uprooting
Changes in land-use have been observed in banana-based systems in the African Great Lakes region affected by Xanthomonas wilt disease (XW) of banana. Through focus group discussions (FGDs) and the 4-cell method (to map the area under production and the number of households involved), changes in land-use were assessed in 13 XW-affected landscapes/villages along a 230 km transect from Masisi (where XW arrived in 2001) to Bukavu (XW arrived around 2014) in the Eastern Democratic Republic of Congo. Farmers' perceptions on the sustainability of new land uses were also documented. Soil nutrient content and erosion levels were measured for five major land-use options/trajectories on 147 fields across 55 farms in three landscapes along the transect. From banana being ranked the most important crop (92% of landscapes) before XW outbreaks, its importance had declined, with it grown on smaller farms by most households in 36% of the landscapes, while in 64% of cases by few households on smaller plots. Farmers uprooted entire banana mats or fields, expanding land under other crops. Species richness did not change at landscape level, although 21 crops were introduced at farm level. Banana is, however, still perceived as more sustainable due to its multi-functional roles. Soils under banana had better chemical attributes, while high erosion levels (Mg ha-1 year-1) occurred under cassava (1.7-148.9) compared with banana (0.3-10.7) and trees (0.3-5.9). The shifts from banana could thus affect supply of key services and sustainability of the farming systems. This study offers a good basis for interventions in XW-affected landscapes.
Palaeosols and their cover sediments of a glacial landscape in northern central Europe : Spatial distribution, pedostratigraphy and evidence on landscape evolution
Kaiser, Knut ; Schneider, Thomas ; Küster, Mathias ; Dietze, Elisabeth ; Fülling, Alexander ; Heinrich, Susann ; Kappler, Christoph ; Nelle, Oliver ; Schult, Manuela ; Theuerkauf, Martin ; Vogel, Sebastian ; Boer, Anna Maartje de; Börner, Andreas ; Preusser, Frank ; Schwabe, Matthias ; Ulrich, Jens ; Wirner, Michael ; Bens, Oliver - \ 2020
Catena 193 (2020). - ISSN 0341-8162
Buried soil - Holocene - Human impact - Land-cover change - Landscape dynamics - Soil erosion
Knowledge of the distribution, types and properties of buried soils, i.e. palaeosols, is essential in understanding how lowlands in northern central Europe have changed over past millennia. This is an indispensable requirement for evaluating long-term human impact including soil erosion and land-cover dynamics. In the Serrahn area (62 km2), a young glacial landscape representative for northeastern Germany and part of the Müritz National Park, 26 pedosedimentary sections were documented and analysed. To this end, a multiproxy-approach was applied using pedology, micromorphology, geochronology, and palaeoecology. Statistical and spatial analyses of c. 5200 soil profiles, of which 10% contain palaeosols, show that buried soils cover an area of 5.7 km2, i.e. 9% of the area studied. Most palaeosols are Cambisols, Arenosols and Gleysols. Palaeosols are mainly covered by aeolian and colluvial sands, as well as by lacustrine sands and peat. Radiocarbon and luminescence dating together with palynological and anthracological data reveal that former land surfaces were dominantly buried through erosion triggered by human activity in the late Holocene. In addition, but to a clearly smaller extent, Lateglacial/early Holocene palaeosols and cover sediments occur. Following Medieval clear-cutting and intensive land use, the study area is today again widely forested. The high share of buried land surfaces detected here is expected to be representative for the hilly glacial landscapes even in the wider region, i.e. in northern central Europe, and should be considered in soil mapping, soil carbon budgeting and assessments of past human impact.
Impact of flight altitude and cover orientation on Digital Surface Model (DSM) accuracy for flood damage assessment in Murcia (Spain) using a fixed-wing UAV
Anders, Niels ; Smith, Mike ; Suomalainen, Juha ; Cammeraat, Erik ; Valente, João ; Keesstra, Saskia - \ 2020
Earth Science Informatics 13 (2020). - ISSN 1865-0473 - p. 391 - 404.
DSM assessment - Fixed-wings - Geomorphology - Low-altitude aerial photography - Remote sensing - Soil erosion - UAV
Soil erosion, rapid geomorphological change and vegetation degradation are major threats to the human and natural environment. Unmanned Aerial Systems (UAS) can be used as tools to provide detailed and accurate estimations of landscape change. The effect of flight strategy on the accuracy of UAS image data products, typically a digital surface model (DSM) and orthophoto, is unknown. Herein different flying altitudes (126-235 m) and area coverage orientations (N-S and SW-NE) are assessed in a semi-arid and medium-relief area where terraced and abandoned agricultural fields are heavily damaged by piping and gully erosion. The assessment was with respect to cell size, vertical and horizontal accuracy, absolute difference of DSM, and registration of recognizable landscape features. The results show increasing cell size (5-9 cm) with increasing altitude, and differences between elevation values (10-20 cm) for different flight directions. Vertical accuracy ranged 4-7 cm but showed no clear relationship with flight strategy, whilst horizontal error was stable (2-4 cm) for the different orthophotos. In all data sets, geomorphological features such as piping channels, rills and gullies and vegetation patches could be labeled by a technician. Finally, the datasets have been released in a public repository.
Comparative analysis of splash erosion devices for rainfall simulation experiments: A laboratory study
Fernández-Raga, María ; Campo, Julián ; Rodrigo-Comino, Jesús ; Keesstra, Saskia D. - \ 2019
Water 11 (2019)6. - ISSN 2073-4441
Environmental assessment - Rainfall simulation - Soil erosion - Splash erosion
For the study of soil erosion it is important to set up the experiments well. In the experimental design one of the key factors is the choice of the measurement device. This is especially important when one part of the erosion process needs to be isolated, such as for splash erosion. Therefore, the main aim of this research is to list the general characteristics of the commonly used splash erosion devices and to discuss the performance, to be able to relate them, and make suggestions regarding their use. The devices we selected for this comparative comparison were: the splash cup, funnel, Morgan tray, Tübingen cup, tower, and the gutter. The devices were tested under the same conditions (rainfall characteristics, slope, and soil type) to assess their hydrological response under different intensities of simulated rainfall. All devices were installed on a sloping plot (10°) with sandy soil, and were exposed to 10 min. of simulated rain with intensities ranging from 60 to 172 mm/h to measure the splashed sediment, and to describe problems and differences among them. The results showed that the Tübingen cup was the best performing device to measure kinetic energy of the rain, but, because of its design, it is not possible to measure the detached splashed sediment under natural (field) conditions. On the other hand, the funnel device showed a significant relation with rain intensity because it loses little sediment to washing. In addition, the device is easy to use and cheap. Therefore, this device is highly recommended to estimated splash erosion. to the good performance measuring the actual splash erosion, because it loses little sediment by washing. The device is also cheap and easy to install and manage.
Evaluation of watershed health using Fuzzy-ANP approach considering geo-environmental and topo-hydrological criteria
Alilou, Hossein ; Rahmati, Omid ; Singh, Vijay P. ; Choubin, Bahram ; Pradhan, Biswajeet ; Keesstra, Saskia ; Ghiasi, Seid Saeid ; Sadeghi, Seyed Hamidreza - \ 2019
Journal of Environmental Management 232 (2019). - ISSN 0301-4797 - p. 22 - 36.
Analytical network process - Fuzzy theory - Multi-criteria decision analysis (MCDA) - Soil erosion - Watershed health
Assessment of watershed health and prioritization of sub-watersheds are needed to allocate natural resources and efficiently manage watersheds. Characterization of health and spatial prioritization of sub-watersheds in data scarce regions helps better comprehend real watershed conditions and design and implement management strategies. Previous studies on the assessment of health and prioritization of sub-watersheds in ungauged regions have not considered environmental factors and their inter-relationship. In this regard, fuzzy logic theory can be employed to improve the assessment of watershed health. The present study considered a combination of climate vulnerability (Climate Water Balance), relative erosion rate of surficial rocks, slope weighted K-factor, topographic indices, thirteen morphometric characteristics (linear, areal, and relief aspects), and potential non-point source pollution to assess watershed health, using a new framework which considers the complex linkage between human activities and natural resources. The new framework, focusing on watershed health score (WHS), was employed for the spatial prioritization of 31 sub-watersheds in the Khoy watershed, West Azerbaijan Province, Iran. In this framework, an analytical network process (ANP) and fuzzy theory were used to investigate the inter-relationships between the above mentioned geo-environmental factors and to classify and rank the health of each sub-watershed in four classes. Results demonstrated that only one sub-watershed (C15) fell into the class that was defined as ‘a potentially critical zone’. This article provides a new framework and practical recommendations for watershed management agencies with a high level of assurance when there is a lack of reliable hydrometric gauge data.
Soilwater conservation : Dynamics and impact
Prima, Simone Di; Castellini, Mirko ; Pirastru, Mario ; Keesstra, Saskia - \ 2018
Water 10 (2018)7. - ISSN 2073-4441 - 6 p.
Crop yields - Soil erosion - Soil water storage - Sustainable land management - Water and soil conservation - Water availability - Water infiltration
Human needs like food and clean water are directly related to good maintenance of healthy and productive soils. A good understanding of human impact on the natural environment is therefore necessary to preserve and manage soil and water resources. This knowledge is particularly important in semi-arid and arid regions, where the increasing demands on limited water supplies require urgent efforts to improve water quality and water use efficiency. It is important to keep in mind that both soil and water are limited resources. Thus, wise use of these natural resources is a fundamental prerequisite for the sustainability of human societies. This Special Issue collects 15 original contributions addressing the state of the art of soil and water conservation research. Contributions cover a wide range of topics, including (1) recovery of soil hydraulic properties; (2) erosion risk; (3) novel modeling, monitoring and experimental approaches for soil hydraulic characterization; (4) improvement of crop yields; (5) water availability; and (6) soil salinity. The collection of manuscripts presented in this Special Issue provides more insights into conservation strategies for effective and sustainable soil and water management.
An integrated method for calculating DEM-based RUSLE LS
Wang, Meng ; Baartman, Jantiene E.M. ; Zhang, Hongming ; Yang, Qinke ; Li, Shuqin ; Yang, Jiangtao ; Cai, Cheng ; Wang, Meili ; Ritsema, Coen J. ; Geissen, Violette - \ 2018
Earth Science Informatics 11 (2018)4. - ISSN 1865-0473 - p. 579 - 590.
Geographic information system (GIS) - LS factor - Revised universal soil loss equation (RUSLE) - Soil erosion
The improvement of resolution of digital elevation models (DEMs) and the increasing application of the Revised Universal Soil Loss Equation (RUSLE) over large areas have created problems for the efficiency of calculating the LS factor for large data sets. The pretreatment for flat areas, flow accumulation, and slope-length calculation have traditionally been the most time-consuming steps. However, obtaining these features are generally usually considered as separate steps, and calculations still tend to be time-consuming. We developed an integrated method to improve the efficiency of calculating the LS factor. The calculation model contains algorithms for calculating flow direction, flow accumulation, slope length, and the LS factor. We used the Deterministic 8 method to develop flow-direction octrees (FDOTs), flat matrices (FMs) and first-in-first-out queues (FIFOQs) tracing the flow path. These data structures were much more time-efficient for calculating the slope length inside the flats, the flow accumulation, and the slope length linearly by traversing the FDOTs from their leaves to their roots, which can reduce the search scope and data swapping. We evaluated the accuracy and effectiveness of this integrated algorithm by calculating the LS factor for three areas of the Loess Plateau in China and SRTM DEM of China. The results indicated that this tool could substantially improve the efficiency of LS-factor calculations over large areas without reducing accuracy.
Testing simple scaling in soil erosion processes at plot scale
Bagarello, Vincenzo ; Ferro, Vito ; Keesstra, Saskia ; Comino, Jesús Rodrigo ; Pulido, Manuel ; Cerdà, Artemi - \ 2018
Catena 167 (2018). - ISSN 0341-8162 - p. 171 - 180.
Natural rainfall - Plots - Runoff - Scale - Sediment concentration - Soil erosion
Explaining scale effects for runoff and erosion improves our understanding and simulation ability of hydrological and erosion processes. In this paper, plot scale effects on event runoff per unit area (Qe), sediment concentration (Ce) and soil loss per unit area (SLe) were checked at El Teularet-Sierra de Enguera experimental site in Eastern Spain. The measurements were carried out for 31 events occurring in the years 2005 and 2007 in bare ploughed plots ranging from 1 to 48 m2. The analysis established the scaling relationship by dimensional analysis and self-similarity theory, and tested this relationship at different temporal scales ranging from event to annual scale. The dimensional analysis and the incomplete self-similarity condition allowed us to establish a power scaling relationship which was found to also be usable for the moments of k (1, 2, 3, 4) order. The power scaling relationship was theoretically deduced applying a boundary condition which is based on the hypothesis that sediment delivery processes do not occur at the selected plot scale. The simple scaling invariance condition was always verified (i.e. for each temporal horizon) for runoff and soil loss while the same hypothesis was not perfectly acceptable for sediment concentration. The analysis of the scaling relationships at event temporal scale showed that the spatial scale effects were less frequent for the composite variable (soil loss = sediment concentration × runoff) than the constituting variables. For 48% of the events, a statistically significant scale effect was detected for all tested variables. With reference to the statistically significant relationships, both runoff and soil loss always decreased and sediment concentration always increased in the passage from the reference area (1 m2) to the largest one (48 m2). The analysis at aggregated temporal scales suggested that annual scale effects for soil loss per unit area should be temporally more stable than those for both runoff and sediment concentration. Finally, at mean event scale the three investigated variables have a similar behaviour in terms of simple scaling invariance.
Integrated, spatial distributed modelling of surface runoff and soil erosion during winter and spring
Starkloff, Torsten ; Stolte, Jannes ; Hessel, Rudi ; Ritsema, Coen ; Jetten, Victor - \ 2018
Catena 166 (2018). - ISSN 0341-8162 - p. 147 - 157.
Freezing and thawing - LISEM - Modelling - Snowmelt - Soil erosion - UEBGrid
In cold climate regions a significant fraction of annual soil erosion in agricultural land occurs during snowmelt and rain on partially frozen soils. Physically based and spatially distributed soil erosion models have proved to be good tools for understanding the processes occurring at catchment scale during rainfall erosion. However, most existing erosion models do not account for snow in a suitable way. A combination of the UEBGrid snow pack model and the LISEM erosion model was therefore used in this study. The aim was to test and validate this model combination and to assess its utility in relation to quantification and process understanding. Applying this model combination to simulate surface runoff and soil erosion showed that, in principle, it is possible to satisfactorily simulate surface runoff and observed soil erosion patterns during winter. The values for the calibration parameters were similar for the two chosen winter periods when the rainfall and snowmelt episodes occurred. However, the calibration procedure showed that the utility of this combination had several limitations. It is hoped that this study can help to improve existing models and trigger new developments in including snow pack dynamics and soil freezing and thawing in soil erosion models.
Afforestation, Subsequent Forest Fires and Provision of Hydrological Services : A Model-Based Analysis for a Mediterranean Mountainous Catchment
Nunes, João Pedro ; Naranjo Quintanilla, Paula ; Santos, Juliana Marisa ; Serpa, Dalila ; Carvalho-Santos, Cláudia ; Rocha, João ; Keizer, Jan Jacob ; Keesstra, Saskia Deborah - \ 2018
Land Degradation and Development 29 (2018)3. - ISSN 1085-3278 - p. 776 - 788.
Forest fires - Hydrological services - Mediterranean region - Soil erosion - Water resources
Mediterranean landscapes have experienced extensive abandonment and reforestation in recent decades, which should have improved the provision of hydrological services such as flood mitigation, soil erosion protection and water quality regulation. However, these forests are fire-prone, and the postfire increase in runoff, erosion and sediment exports could negatively affect service provision. This issue was assessed by using the Soil and Water Assessment Tool model for the Macieira de Alcôba mountain catchment in northwestern Portugal, covered by agriculture and forest plantations, monitored in 2010-2014 and partially burnt in 2011. The model was validated for streamflow, sediment yield and erosion in agricultural fields and burnt hillslopes, showing that it can be adapted for postfire simulation. Model results for a decadal assessment (2004-2014) show that the fire increased erosion in the burnt slopes from 0.1 to 46.5 Mg ha-1 y-1 and catchment sediment yield from 0.14 to 2.1 Mg ha-1 y-1. Erosion in the burnt forest during this decade was 1 order of magnitude above that in agricultural fields. Model results for different fire and land-use scenarios indicate that postfire erosion and sediment yield were lower without postfire soil management for reforestation and when the fire occurred in pine forests (land use before the 1990s) or in shrublands (land-use before afforestation in the 1930s). These impacts were robust to changes in postfire weather and to a longer (20 years) unburnt period. The results suggest that, in the long term, Mediterranean fire-prone forests might not provide the anticipated soil protection and water quality regulation services.
Integrating Extensive Livestock and Soil Conservation Policies in Mediterranean Mountain Areas for Recovery of Abandoned Lands in the Central Spanish Pyrenees. A Long-Term Research Assessment
Nadal-Romero, Estela ; Lasanta, Teodoro ; Cerda Bolinches, Artemio - \ 2018
Land Degradation and Development 29 (2018)2. - ISSN 1085-3278 - p. 262 - 273.
Controlled burn - Farmland abandonment - Livestock farming - Mediterranean mountains - Pyrenees - Shrubland recovery - Soil erosion - Soil quality
Land abandonment is a global issue with important implications in Mediterranean mountain areas. Abandoned Mediterranean croplands start a process of secondary succession that is initially colonized by grasslands, shrubs and forest. In Mediterranean mountain areas, the process is very slow, so the shrubs remain for decades, preventing livestock from accessing pastureland. Therefore, farmers have to burn or clear the shrubs in order to provide pasture, a practice that has recently been encouraged by several regional governments in Spain. Data from experimental plots of the Aísa Valley Experimental Station in the Spanish Pyrenees allow to evaluate the effects of burning and clearing shrubs on physical and chemical soil properties, runoff production and soil erosion rates. The results suggested that clearing shrubs returned more positive results than burning, as it improved soil quality and slowed soil erosion while producing slightly higher runoff coefficients, which is very important in Mediterranean environments where water is a scarce resource. Clearing shrubs improves soil characteristics by increasing organic matter and CN ratio, which promote the expansion of herbaceous species with a high pastoral value. The results suggested that the policy of clearing shrubs is suitable for managing abandoned lands in Mediterranean mountain areas. Further studies at catchment scale will be needed to confirm the impact of substituting shrubs for meadows and to understand the connectivity of the flows measured from pedon and slope to the watershed scale.
Catchment hydrology during winter and spring and the link to soil erosion: A case study in Norway
Starkloff, Torsten ; Hessel, Rudi ; Stolte, Jannes ; Ritsema, Coen - \ 2017
Nordic Hydrology 4 (2017)1. - ISSN 0029-1277
Infiltration - Modelling - SHAW - Snow - Soil erosion - Soil freezing
In the Nordic countries, soil erosion rates in winter and early spring can exceed those at other times of the year. In particular, snowmelt, combined with rain and soil frost, leads to severe soil erosion, even, e.g., in low risk areas in Norway. In southern Norway, previous attempts to predict soil erosion during winter and spring have not been very accurate owing to a lack of catchment-based data, resulting in a poor understanding of hydrological processes during winter. Therefore, a field study was carried out over three consecutive winters (2013, 2014 and 2015) to gather relevant data. In parallel, the development of the snow cover, soil temperature and ice content during these three winters was simulated with the Simultaneous Heat and Water (SHAW) model for two different soils (sand, clay). The field observations carried out in winter revealed high complexity and diversity in the hydrological processes occurring in the catchment. Major soil erosion was caused by a small rain event on frozen ground before snow cover was established, while snowmelt played no significant role in terms of soil erosion in the study period. Four factors that determine the extent of runoff and erosion were of particular importance: (1) soil water content at freezing; (2) whether soil is frozen or unfrozen at a particular moment; (3) the state of the snow pack; and (4) tillage practices prior to winter. SHAW performed well in this application and proved that it is a valuable tool for investigating and simulating snow cover development, soil temperature and extent of freezing in soil profiles.
An economic, perception and biophysical approach to the use of oat straw as mulch in Mediterranean rainfed agriculture land
Cerdà, Artemi ; Rodrigo Comino, Jesús ; Giménez-Morera, Antonio ; Keesstra, Saskia D. - \ 2017
Ecological Engineering 108 (2017). - ISSN 0925-8574 - p. 162 - 171.
Cost - No-tillage - Perception - Runoff - Soil erosion - Straw mulch
Soil erosion is a key cause of land degradation in agriculture lands; and it is a worldwide threat that must be solved by means of nature-based strategies to be able to achieve sustainability. The use of mulches can be a solution, but there is a lack of information on long-term effects of the use of straw. Furthermore, little is known about the perception of farmers and the economic cost on the implantation of straw as a conservation measure. Eight paired plots were selected in Sierra de Enguera on an agriculture field to determine the effect of straw cover on soil erosion. Four plots were tilled three times per year (Control) and four plots were not ploughed and 0.125 kg m−2 y−1 of oat straw cover was applied yearly (Straw). The plots were established in 2002, and runoff and sediment was continuously collected after each rainfall event from 2004 till 2014 when the two managements were applied. The results show an immediate effect of the straw mulches as in these plots the runoff (from 7.7 till 5.9%) and soil erosion (from 47 till 26 Mg ha−1 y−1) was reduced already in the first year. The combined effect of the use of straw yearly and the no-tillage strategy resulted in a reduction of the sediment yield, and 11 years later soil erosion rates were two orders of magnitude lower than in the control plot. However, the perception of the farmers on the use of straw is very negative and they claim that subsidies need to be implemented, as the cost of straw mulch is 1.9 times more expensive than traditional tillage.
An improved method for calculating slope length (λ) and the LS parameters of the Revised Universal Soil Loss Equation for large watersheds
Zhang, Hongming ; Wei, Jicheng ; Yang, Qinke ; Baartman, Jantiene E.M. ; Gai, Lingtong ; Yang, Xiaomei ; Li, Shu Qin ; Yu, Jiantao ; Ritsema, Coen J. ; Geissen, Violette - \ 2017
Geoderma 308 (2017). - ISSN 0016-7061 - p. 36 - 45.
GIS - LS - RUSLE - Soil erosion - Terrain analysis
The Universal Soil Loss Equation (USLE) and its revised version (RUSLE) are often used to estimate soil erosion at regional landscape scales. USLE/RUSLE contain parameters for slope length factor (L) and slope steepness factor (S), usually combined as LS. However a major limitation is the difficulty in extracting the LS factor. Methods to estimate LS based on geographic information systems have been developed in the last two decades. L can be calculated for large watersheds using the unit contributing area (UCA) or the slope length (λ) as input parameters. Due to the absence of an estimation of slope length, the UCA method is insufficiently accurate. Improvement of the spatial accuracy of slope length and LS factor is still necessary for estimating soil erosion. The purpose of this study was to develop an improved method to estimate the slope length and LS factor. We combined the algorithm for multiple-flow direction (MFD) used in the UCA method with the LS-TOOL (LS-TOOLSFD) algorithms, taking into account the calculation errors and cutoff conditions for distance, to obtain slope length (λ) and the LS factor. The new method, LS-TOOLMFD, was applied and validated in a catchment with complexly variable slopes. The slope length and LS calculated by LS-TOOLMFD both agreed better with field data than with the calculations using the LS-TOOLSFD and UCA methods, respectively. We then integrated the LS-TOOLMFD algorithm into LS-TOOL developed in Microsoft's.NET environment using C# with a user-friendly interface. The method can automatically calculate slope length, slope steepness, L, S, and LS factor, providing the results as ASCII files that can be easily used in GIS software and erosion models. This study is an important step forward in conducting accurate large-scale erosion evaluation.
Assessing the effect of water harvesting techniques on event-based hydrological responses and sediment yield at a catchment scale in northern Ethiopia using the Limburg Soil Erosion Model (LISEM)
Grum, Berhane ; Woldearegay, Kifle ; Hessel, Rudi ; Baartman, Jantiene E.M. ; Abdulkadir, Mohammed ; Yazew, Eyasu ; Kessler, Aad ; Ritsema, Coen J. ; Geissen, Violette - \ 2017
Catena 159 (2017). - ISSN 0341-8162 - p. 20 - 34.
Calibration - Northern Ethiopia - Rain intensity - Runoff - Soil erosion
Runoff and sediment yield in semi-arid catchments are highly influenced by infrequent but very heavy rains. These events occur over short temporal scales, so runoff and sediment transport can only be understood using an event-based analysis. We applied a hydrological and soil-erosion model, LISEM, to the Gule catchment (~ 12 km2) in northern Ethiopia. The objectives of the study were: (a) to evaluate the performance of LISEM in describing event-based hydrological processes and sediment yield in a catchment under the influence of different water harvesting techniques (WHTs), and (b) to study the effect of the WHTs on catchment-scale event-based runoff and sediment yield. The model performed satisfactorily (NSE > 0.5) for most of the events when discharge was calibrated at the main outlet (Gule) and at a sub-outlet (Misbar). Runoff coefficients for the Gule catchment and Misbar sub-catchment were expectedly low due to the implementation of WHTs, which can store runoff from the rains and increase infiltration into the soil. Simulated and measured sediment yields were of similar orders of magnitude. LISEM generally overestimated sediment yield compared to the measurements. The poor performance of LISEM in predicting sediment yield could be attributed to the uncertainty of several factors controlling soil erosion and the inadequacy of LISEM in describing soil erosion on steep slopes. Catchment-scale model simulations indicated that runoff and sediment yield could be effectively reduced by implementing WHTs. The model estimated 41 and 61% reductions in runoff and sediment yield at the Gule outlet, respectively. Similarly, runoff and sediment yield at the Misbar sub-outlet were reduced by 45 and 48%, respectively. LISEM can thus be used to simulate the effects of different existing or new WHTs on catchment hydrology and sediment yield. The results of scenario predictions could be useful for land-use planners who intend to implement different measures of catchment management.
Soil erosion processes in European vineyards: A qualitative comparison of rainfall simulation measurements in Germany, Spain and France
Comino, Jesús Rodrigo ; Iserloh, Thomas ; Morvan, Xavier ; Issa, Oumarou Malam ; Naisse, Christophe ; Keesstra, Saskia D. ; Cerdà, Artemio ; Prosdocimi, Massimo ; Arnáez, José ; Lasanta, Teodoro ; Ramos, María Concepción ; Marqués, María José ; Colmenero, Marta Ruiz ; Bienes, Ramón ; Sinoga, José Damián Ruiz ; Seeger, Manuel ; Ries, Johannes B. - \ 2016
Nordic Hydrology 3 (2016)1. - ISSN 0029-1277
Qualitative comparison - Rainfall simulation - Soil erosion - Soil hydrology - Vineyards
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.
Quantitative comparison of initial soil erosion processes and runoff generation in Spanish and German vineyards
Rodrigo Comino, J. ; Iserloh, T. ; Lassu, T. ; Cerdà, A. ; Keesstra, Saskia D. ; Prosdocimi, M. ; Brings, C. ; Marzen, M. ; Ramos, M.C. ; Senciales, J.M. ; Ruiz Sinoga, J.D. ; Seeger, M. ; Ries, J.B. - \ 2016
Science of the Total Environment 565 (2016). - ISSN 0048-9697 - p. 1165 - 1174.
Environmental factors - Infiltration - Rainfall simulation experiments - Runoff - Soil erosion - Vineyards
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.
Climate data used to study the potential impacts of climate change on future hydrological regimes and water resources (2010-2050) in the Philippines
Tolentino, Pamela Louise M. ; Poortinga, A. ; Kanamaru, Hideki ; Keesstra, S.D. ; Maroulis, J. ; David, Carlos Primo C. ; Ritsema, C.J. - \ 2016
climate change - Climate models - Hydrological regimes - Soil erosion - Water resources
The collection contains downscaled ERA-Interim and climate scenario data, derived from three global climate models (BCM2, CNCM3 and MPEH5), for the Philippines. ERA-Interim (1979-2010) is the reanalysis dataset used to generate climate data in the absence of actual climate observations.