Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2017
Abstract
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.
Abstract
The nature of subsurface flow depends largely on hydraulic conductivity of the vadoze zone, the permeability of the underlying bedrock, the existence of soil layers differing in hydraulic properties and macropore content, soil depth and slope angle. Quantification of flow pathways on forested hillslopes is essential to understand the hydrological dynamics and solute transport patterns. Acrisols, with their argic Bt horizons, are challenging in this respect. To increase the understanding of flow pathways of water and the short-term variability of the soil moisture patterns in Acrisols, a field study was conducted on a forested hillslope in the Tie Shan Ping (TSP) watershed, 25 km northeast of Chongqing city, PR China. This catchment is covered by mixed secondary forest dominated by Masson pine (Pinus Massoniana). The soil's Ksat reduced significantly at the interface between the AB and Bt horizons (2.6E-05 versus 1.2E-06 m s−1). This led to that the flow volume generated in the Bt horizon was of little quantitative importance compared to that in the AB horizon. There was a marked decrease in porosity between the O/A horizon and the AB horizon, with a further decrease deeper in the mineral subsoil. Especially the content of pores >300 µm were higher in the AB horizon (14.3%) compared to the Bt horizon (6.5%). This explains the difference in Ksat values. Our study shows that Bt horizons have limited water transport capability, forcing part of the infiltrated rainwater as interflow through the OA and AB horizons. The topsoil thus responds quickly to rainfall events, causing frequent cycles of saturation and aeration of soil pores
Abstract
Climate change is expected to alter average temperature and precipitation values and to increase the variability of precipitation events, which may lead to even more intense and frequent water hazards. Water hazards engineering is the branch of engineering concerned with the application of scientific and engineering principles for protection of human populations from the effects of water hazards; protection of environments, both local and global, from the potentially deleterious effects of water hazards; and improvement of environmental quality for mitigating the negative effects of water hazards. An integrated approach of water hazards engineering based on mapping, nature-based and technical solutions will constitute a feasible solution in the process of adapting to challenges generated by climate changes worldwide. This paper will debate this concept also providing some examples from several European countries.
Abstract
Shallow (<1 m deep) snowpacks on agricultural areas are an important hydrological component in many countries, which determines how much meltwater is potentially available for overland flow, causing soil erosion and flooding at the end of winter. Therefore, it is important to understand the development of shallow snowpacks in a spatially distributed manner. This study combined field observations with spatially distributed snow modelling using the UEBGrid model, for three consecutive winters (2013–2015) in southern Norway. Model performance was evaluated by comparing the spatially distributed snow water equivalent (SWE) measurements over time with the simulated SWE. UEBGrid replicated SWE development at catchment scale with satisfactory accuracy for the three winters. The different calibration approaches which were necessary for winters 2013 and 2015 showed the delicacy of modelling the change in shallow snowpacks. Especially the refreezing of meltwater and prohibited runoff and infiltration of meltwater by frozen soils and ice layers can make simulations of shallow snowpacks challenging.
Abstract
Land management and spatial planning are closely linked to the adaptation of water management to climate change impacts. Land management has an influence on the ability of the soil to retain precipitation or flood water and sustainable land use can help to better manage risks related to both increased precipitation/flooding and water scarcity. Land and soil management can also realize significant synergies between climate change adaptation and mitigation. Agriculture as a key form of land use will play a crucial role in adaptive spatial planning approaches. Intensive agriculture in flood-prone areas is at risk of substantial economic loss in the case of flooding. On the other hand, the increased challenges for flood risk management will create a demand for new ways of accommodating flood water and managing flows, which may increase economic opportunities for water farming. There are sufficient reasons to understand land drainage arrangements importance. Drainage has been identified as the forgotten factor in sustaining a sustainable irrigated agriculture. Surface and subsurface drainage provides a lot of functions that meet some actual and challenging needs. Some of these functions are: resource base protection for food production; sustaining and increasing the yields and rural incomes; irrigation investment protection etc. This paper is based on an analysis of managing water excess in north-western Romania using Romanian expertise in this field but also the results from some bilateral projects between Romania, Norway and Iceland.
Abstract
In the Nordic countries, changes in pore structure during winter can affect e.g. water transport capacity in soils after winter. A reduction in pore space can cause an increase in runoff volume due to snowmelt and rain, resulting in flooding and soil erosion. This study quantified the effect of freezing-thawing cycles (FTCs) on the macropore structure of a silt and a sandy soil. Six consecutive FTCs were applied to intact soil samples, which were scanned after 0, 1, 2, 4 and 6 FTCs with an industrial X-ray scanner. Using state-of-the-art image processing and analysis techniques, changes in soil macropore network characteristics were quantified. The results showed that freezing-thawing affected the looser sandy soil more than the silt with its more cohesive structure. However, in both soils freezing-thawing had a negative effect on properties of macropore networks (e.g. reduction in macroporosity, thickness and specific surface area of macropores). These findings can help improve understanding of how undisturbed soils react to different winter conditions, which can be beneficial in the development of models for predicting flooding and soil erosion.
Abstract
The moisture status of the upper 10cm of the soil profile is a key variable for the prediction of a catchment's hydrological response to precipitation, and of pivotal importance to the estimation of trafficability. Prediction, and even mapping, of topsoil water content is complicated, not in the least because of its large spatial heterogeneity. In IRIDA, an EU/JPI project, measurements, models and weather predictions will be applied to estimate the soil moisture status at the sub-field scale in near-real time. The project is in its early stages, during which the relevant parameters will be selected that will allow for soil moisture mapping on agricultural fields at a 10 m resolution.
Authors
Diego Faustolo Alves Bispo Marx Leandro Naves Silva Joao Jose Granate de Sa e Melo Marques Marianne Bechmann Pedro Velloso Gomes Batista Nilton CuriAbstract
Identifying and ranking nutrient loss risk areas are important steps towards integrated catchment management. This study aimed to apply the P index model at the Posses catchment, south of the state of Minas Gerais, Brazil. We applied the P index for the current land use at the Posses catchment and for two hypothetical scenarios: scenario 1, in which P fertilizer was applied to all land uses, except for native forests; and scenario 2, which considered the use of P fertilizer as in scenario 1, and that the Environmental Protection Areas referring to the riparian forests and springs were totally restored. Considering current land use, almost the whole catchment area (91.4%) displayed a low P loss risk. The highest P index was associated to croplands and eucalyptus plantations. Regarding scenario 1, areas under pasture fell into the low (15.1%), medium (45.5%), high (27.1%) and very high (12.3%) P index categories. Environmental Protection Areas on scenario 2 decreased the P loss risk from the scenario 1 in 37.6%. Hence, the model outputs indicate that the reforestation of buffer zones can decrease P loss risk in the case increasing use of P fertilizer. The P index model is a potential support tool to promote judicious use of fertilizers and conservation practices at the Posses catchment.
Authors
Annette Dathe Attila Nemes Esther Bloem Matthew Patterson Daniel Gimenez Anna Angyal Johannes Koestel Nicholas JarvisAbstract
No abstract has been registered
Authors
Annette Dathe Attila Nemes Esther Bloem Matthew Patterson Daniel Gimenez Julia Szocs Johannes Koestel Nicholas JarvisAbstract
No abstract has been registered