Vedlegg

CV

Biografi

Dr. Jannes Stolte har mer enn 20 års erfaring i grunnleggende og anvendt forskning på området nedbørfelt prosesser og hydrologi, og deltar i og koordinerer store (inter)nasjonale tverrfaglige forskningsprosjekter. Hans interesse fokuserer på land-hydrologi interaksjoner på ulike romlige, tidsmessige og klima skalaer, med spesiell oppmerksomhet på jord fysiske prosesser. Han jobber som forsker ved NIBIO, og arbeider med virkningen av klimaendringer på avrenning av små nedbørfelter i Norge, med fokus på flom, flomdempende tiltak og jordtap. Jannes er avdelingsleder Jordressurser og arealbruk i Miljø og naturresurser divisjonen.

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Sammendrag

Klimaet forventes å bli våtere, varmere og villere. Faren for økt avrenning, flom og jorderosjon vil øke, med påfølgende fare for høyere tilførsler av næringsstoff fra landbruket til vannforekomster. Det finnes mange undersøkelser og publikasjoner om overvannstiltak, og basert på denne informasjonen presenterer vi her en oversikt over tiltak som har til formål å holde vannet lengst mulig i nedbørfeltet, både i skogen og i typiske jordbruksområder, og som er egnet til bruk i Norge. Vi indikerer viktigste virkemåte av tiltakene: «forsink og fordrøy» (F) og/eller «fang og infiltrer»

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The hydrological processes associated with vegetation and their effect on slope stability are complex and so difficult to quantify, especially because of their transient effects (e.g. changes throughout the vegetation life cycle). Additionally, there is very limited amount of field based research focusing on investigation of coupled hydrological and mechanical influence of vegetation on stream bank behavior, accounting for both seasonal time scale and different vegetation types, and none dedicated to marine clay soils (typically soil type for Norway). In order to fill this gap we established hydrological and mechanical monitoring of selected test plots within a stream bank, covered with different types of vegetation, typical for Norwegian agricultural areas (grass, shrubs and trees). The soil moisture, groundwater level and stream water level were continuously monitored. Additionally, soil porosity and shear strength were measured regularly. Observed hydrological trends and differences between three plots (grass, tree and shrub) were analysed and formed the input base for stream bank stability modeling. We did not find particular differences between the grass and shrub plot but we did observe a significantly lower soil moisture content, lower soil porosity and higher shear strength within the tree plot. All three plots were stable during the monitoring period, however modeling scenarios made it possible to analyse potential differences in stream bank stability under different vegetation cover depending on root reinforcement and slope angle.

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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.

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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.

Sammendrag

Liermåsan like nord for Bjørkelangen er et torvuttak som er under avslutning på ca 1,2 km2. Lierelva renner forbi torvuttaket og rett inn i Bjørkelangen sentrum. Området har problemer med flom, og rapporten har utredet potensialet og metoder for hvordan Liermåsan kan brukes til fordrøyning for å dempe flommene. Areal- og volumberegninger viser at Liermåsan kan lagre fra ca 165000 m3 til ca 2400000 m3 etter hvor omfattende tiltak som gjøres. For å redusere en 20-årsflom til en 10-årsflom i en time trengs 26640 m3, for ett døgn ca 640000 m3. Tilsvarende kan en redusere en 100-årsflom til en 50-årsflom i en time med 35000 m3. Dette viser at arealet har potensiale for å dempe flomtoppene.....

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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

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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.

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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.

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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.

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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.

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Biophysical restoration or rehabilitation measures of land have demonstrated to be effective in many scientific projects and small-scale environmental experiments. However circumstances such as poverty, weak policies, or inefficient scientific knowledge transmission can hinder the effective upscaling of land restoration and the long term maintenance of proven sustainable use of soil and water. This may be especially worrisome in lands with harsh environmental conditions. This review covers recent efforts in landscape restoration and rehabilitation with a functional perspective aiming to simultaneously achieve ecosystem sustainability, economic efficiency, and social wellbeing. Water management and rehabilitation of ecosystem services in croplands, rangelands, forests, and coastlands are reviewed. The joint analysis of such diverse ecosystems provides a wide perspective to determine: (i) multifaceted impacts on biophysical and socio-economic factors; and (ii) elements influencing effective upscaling of sustainable land management practices. One conclusion can be highlighted: voluntary adoption is based on different pillars, i.e. external material and economic support, and spread of success information at the local scale to demonstrate the multidimensional benefits of sustainable land management. For the successful upscaling of land management, more attention must be paid to the social system from the first involvement stage, up to the long term maintenance.

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Despite numerous research efforts over the last decades, integrating the concept of ecosystem services into land management decision-making continues to pose considerable challenges. Researchers have developed many different frameworks to operationalize the concept, but these are often specific to a certain issue and each has their own definitions and understandings of particular terms. Based on a comprehensive review of the current scientific debate, the EU FP7 project RECARE proposes an adapted framework for soil-related ecosystem services that is suited for practical application in the prevention and remediation of soil degradation across Europe. We have adapted existing frameworks by integrating components from soil science while attempting to introduce a consistent terminology that is understandable to a variety of stakeholders. RECARE aims to assess how soil threats and prevention and remediation measures affect ecosystem services. Changes in the natural capital's properties influence soil processes, which support the provision of ecosystem services. The benefits produced by these ecosystem services are explicitly or implicitly valued by individuals and society. This can influence decision- and policymaking at different scales, potentially leading to a societal response, such as improved land management. The proposed ecosystem services framework will be applied by the RECARE project in a transdisciplinary process. It will assist in singling out the most beneficial land management measures and in identifying trade-offs and win–win situations resulting from and impacted by European policies. The framework thus reflects the specific contributions soils make to ecosystem services and helps reveal changes in ecosystem services caused by soil management and policies impacting on soil. At the same time, the framework is simple and robust enough for practical application in assessing soil threats and their management with stakeholders at various levels.

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Tap av jord som følge av flom og ras er en problemstilling som kan bli stadig mer aktuell i Norge hvis klimascenarier med hyppigere og mer intens nedbør slår til. Flomskader i Norge regnes ofte i form av tap av fast eiendom og infrastruktur, men med et politisk mål om å øke matproduksjonen med 20 % i de neste 15-20 årene blir bevaring av matjord stadig viktigere. I tillegg er tiltak mot tap av næringsrik jord i mange vassdrag vesentlig for å oppnå miljømålene knyttet til vannforskriften. I et seminar 8. oktober 2015 satte Norsk Jordforening og Norsk Vannforening i samarbeid fokus på disse problemstillingene. I dette faktaarket oppsummeres foredrag og diskusjon fra seminaret.

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A physically-based, distributed hydrological model (MIKE SHE) was used to quantify overland runoff in response to four extreme rain events and four types of simulated land use measure in a catchment in Norway. The current land use in the catchment comprises arable lands, forest, urban areas and a stream that passes under a motorway at the catchment outlet. This model simulation study demonstrates how the composition and configuration of land use measures affect discharge at the catchment outlet differently in response to storms of different sizes. For example, clear-cutting on 30% of the catchment area produced a 60% increase in peak discharge and a 10% increase in total runoff resulting from a 50-year storm event in summer, but the effects on peak discharge were less pronounced during smaller storms. Reforestation of 60% of the catchment area was the most effective measure in reducing peak flows for smaller (2-, 5- and 10-year) storms. Introducing grassed waterways reduced water velocity in the stream and resulted in a 28% reduction in peak flow at the catchment outlet for the 50-year storm event. Overall, the results indicate that the specific effect of land use measures on catchment discharge depends on their spatial distribution and on the size and timing of storm events.

Sammendrag

The source of input data for soil physical properties may contribute to uncertainty in simulated catchment response. The objective of this study was to quantify the uncertainty in catchment surface runoff and erosion predicted by the physically based model LISEM, as influenced by uncertainty in soil texture and SOM content, and the pedotransfer function derived soil water retention curve, hydraulic conductivity, aggregate stability and cohesion. LISEM was first calibrated using measured data in a sub-catchment, and then run for the whole catchment for a summer storm event with basic input data from two data sources: soil series specific generic data from the national soil survey database, and measured data collected in a grid within the catchment. The measured data were assigned in two ways: mean values per map unit, or random distribution (50 realizations) per map unit. The model was run both for a low risk situation (crop covered surface) and a high risk situation (without crop cover and with reduced aggregate stability and cohesion). The main results were that 1) using non-local database data yielded much higher peak discharge and five to six times higher soil loss than using locally measured data, 2) there was little difference in simulated runoff and soil loss between the two approaches (mean value versus randomdistribution) to assign locally measured data, 3) differences between the 50 random realizationswere insignificant, for both low-risk and high-risk situations, and 4) uncertainty related to input data could result in larger differences between runswith different input data source than between runswith the same input data source but extreme differences in erosion risk. The main conclusion was that inadequate choice of input data source can significantly affect general soil loss and the effect of measures.

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The recent flooding episode in Norway from May this year shows the necessity of understanding the processes of water discharge from small tributaries feeding the larger river systems. The major objective of the recently started ExFlood project is to define and analyze measures to combat negative impact of extreme weather events on infrastructure in small watershed areas in Norway and to incorporate this in a land use planning tool. Urban, agriculture, nature, and forest areas and infrastructure elements demands different approaches concerning impacts of and opportunities for extreme weather events. The approach of the ExFlood project is to reduce the peak flow and delay the peak time to avoid damages on infrastructure. Three municipalities from different climate regions in Norway contribute to the project where the planning tool will be tested, and an experimental catchment site is selected to conduct in depth process studies.

Sammendrag

Within the scope of the ClimRunoff project, it is necessary to develop an accurate method for estimating peak discharges for the purpose of correctly sizing hydraulic structures at road and rail crossings. The presence of a snowpack and/or ice has an impact on the way the watershed will react to rain events. The first step in understanding the effects of the changing climate is to understand the reaction of the catchment to situations that are happening in today"s climate. After correctly modeling the processes currently occurring during cold seasons today, future scenarios can be modeled to see what effects changes in precipitation patterns and temperatures will have on catchment hydrology. The overall goal of this work is to provide an accurate estimate of runoff water produced from snowmelt on a catchment scale in order to support the development of more accurate methods of estimating peak discharge for road drainage structures. Use is made of the Utah Energy Balance model and the LISEM model. The coupling of the UEB and LISEM models provides valuable insight into the hydrological processes and responses occurring during winter periods. However, more work is needed to improve our understanding and quantification of soil-water interactions during cold periods, which can cause great deviations from hydrologic processes observed during warmer periods.

Sammendrag

Bioforsk er engasjert for å etterprøve flomanalyse foretatt av Multiconsult etter utbygging av ny E6 forbi Taraldrud, fordi det i et område ved gårdsveien stadig ble registrert oversvømmelser. Gjennomgangen viste at modellverktøyet var brukt korrekt, og alle endringer i avrenningsfaktor og nedbørfelt var tatt inn ved beregningene. Konklusjonen om at utvidelsen av E6 ikke ga signifikant økning av flommer i problemområdet kan støttes av Bioforsk. Alle avvik som ble funnet viste mindre økning enn det som var angitt i Multiconsults opprinnelige beregning, fordi deler av nedbørfeltet var ført ut av området via rensesystemer. Flommene må ut fra dette ha andre årsaker enn veiutbyggingen, som for eksempel feilplassert kulvert, nedsynking av veilegeme eller dårlig kanalvedlikehold og tette rister.

Sammendrag

Climate changes will increase the frequency of extreme precipitation events, floods and snow melt periods experienced by the infrastructure. According to initial analysis by the Norwegian transport sector these changes will affect road maintenance, emergency planning, design of new roads and infrastructure. Increased frequency of floods is expected to cause more closed roads because of insufficient and badly maintained drainage systems. Increased ground frost and ice formation on ground surface cause large increases in surface runoff during snowmelt. Recently, in Norway the ClimRunoff project has started with the focus on quantifying discharge of catchment areas draining towards roads. The first priority of the project is to create a model that can evaluate the run-off situations under spring situation (i.e. overland flow due to snowmelt and partially frozen soils). The model is tested on a well-defined catchment under autumn situation. Preliminary results of the model calculations will be presented, together with the challenges to alter the model to be able to calculate snowmelt and frozen soil conditions. In close cooperation with the Norwegian road authorities, areas with historical flooding events are selected, and current and future climate data will be used to analyse the infrastructure of the road construction. Together with a risk analysis of the vulnerability of the transport infrastructure the model will be used to create guidelines for