| 1. |
- Forsman, Åsa, 1972-, et al.
(författare)
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Reduced models for efficient simulation of spatially integrated outputs of one-dimensional substance transport models
- 2003
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Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 18:4, s. 319-327
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Tidskriftsartikel (refereegranskat)abstract
- We examined under what circumstances the results of a large number of runs of the one-dimensional, physics-based SOIL/SOILN nitrate transport model can be combined into a reduced (or meta) model. We considered the total flow of nitrate from a given area and investigated when and how hidden linear structures can be extracted from the underlying model. The presence of such structures can justify the use of spatially aggregated inputs to compute spatially aggregated outputs. Extensive Monte-Carlo simulations showed that some linear structures emerged when the outputs for a long period of time were summed. Other linear structures appeared as relationships between two different components of the model outputs. However, different cropping systems respond differently to changes in anthropogenic or meteorological forcings. Therefore, we derived a reduced model of long-term leaching of nitrogen from the root zone in an agricultural area by combining each combination of soil type and cropping system. Reduced models can help make process-oriented models more transparent, and they are particularly suitable for incorporation into decision support systems.
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| 2. |
- Jansson, Per-Erik., et al.
(författare)
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A coupled model of water, heat and mass transfer using object orientation to improve flexibility and functionality
- 2001
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Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 16:1, s. 37-46
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Tidskriftsartikel (refereegranskat)abstract
- The challenge of our software development is to introduce user-friendly document-orientation and graphical features that are typical in Windows software and to retain the possibility of easily extending existing legacy Fortran code. Keys to this development were the use of five development tools and our special management of shared memory. Numerical development of the code was thus continued in Fortran while the newly introduced multiple-document interface allows the new graphical features that are considered more user friendly (e.g. tool bar, status bar, animation, etc.) can be further refined and adjusted using Visual C++6.0 and the MS Visual Studio. Object orientation makes it possible to include modules with different type of dependencies that restrict the user interface to the specific use of the model. A large number of sub-models are combined and all input/output data have been adapted to an object-oriented standard. Multiple-run features and built-in links to a common database are new important features.
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| 3. |
- Sivertun, Åke, 1950-, et al.
(författare)
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Non-point source critical area analysis in the Gissel÷ watershed using GIS
- 2003
-
Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 18:10, s. 887-898
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Tidskriftsartikel (refereegranskat)abstract
- In the southeast in Norrk÷ping, Sweden, is a small fjord-like bay called SlΣtbaken. The water quality in SlΣtbaken - with its narrow outlet to the Baltic Sea - depends highly on the water quality of the streams that flow in it. While point pollution sources can be identified easily in general, the non-point sources are harder to find. The most important sources for non-point pollution are agricultural areas, and the pollutants are mostly nutrients like phosphorus, which come from the fertilisation of the fields. One important catchment area for SlΣtbaken is the 57.7 km2 Gissel÷ river basin (part of the topographic map 8GNO), which contains large agricultural areas. The transport of water pollutants is based on the same hydrological processes as erosion and sediment transport. The implementation of such a model in a GIS allows the analysis of a large area with a high resolution. When choosing the model, special attention was paid to the possibility of using a verified model that is easy to implement in a commercial GIS without the need of too much expert knowledge. This may allow its widespread use in many administrative applications that need non-point source information. A feasibility test for an enhanced GIS USLE model was done in the Gissel÷ drainage basin before it was implemented for all river basins in the whole administrative area of Norrk÷pings kommun. It is possible to use the suggested simplified USLE model to estimate the load of both pollutants and sediments, and it is able to show the areas that are critical for the water quality at the outlet of the water basin. The model has been evaluated in three studies [Int. J. Geogr. Inf. Syst. 2 (4) (1988) 365, A GIS to target critical areas for non point source management, in: Proceedings of the International Non Point Source Management Symposium, Austin, TX, November 7, 1989, Vatten 48 (1992) 117]. Then, implemented in a very simple GIS that allowed only rough estimates of terrain models and distances, the model was able to estimate the total suspended solids (TSS) and total phosphorus (TP) loads in the Svartσ river basin of 1539 km2 in the same region as Gissel÷ and the Bornsj÷ river basin outside Stockholm. Besides an estimated R2 of 0.91-0.98 (verified by a more than one year measurement from manual and automated sampling stations in the whole river basin), the benefit with the GIS implemented USLE was the possibility to identify the risk areas with high spatial accuracy. During the last decade, both available databases and software have changed the possibilities to identify areas at risk of nutrient leakage. Schein [GIS Methods for Monitoring Sustainable Development by Analysis of Land-use and Land Cover Changes in the Surroundings of Link÷ping (Sweden), Institut fⁿr Photogrammetrie und Fernerkundung, Technische UniversitΣt Dresden, Germany] and Schein and Sivertun [Method and models for sustainable development monitoring and analyses in GIS, in: Proceedings of the International Workshop on Geo-Spatial Knowledge Processing for Natural Resource Management, University of Insubria, Varese, Italy, June 28-29, 2001] show that the enhanced land use data available through the European Union agricultural support program can be used together with remote sensing data to fine tune the modified GIS USLE model. The problems with the new 50 x 50 m digital elevation data now available are also pointed out here. Obvious errors in the data and possibilities to enhance the model by introducing a better terrain model were two important suggestions in these works. In this article, two modifications to the original model are suggested. One is enhancement of the digital terrain model by using height curves from the digital 1:50 000 scale topographic map, and the other is a smooth distance function that better reflects the impact of nutrients on water bodies. Because of its easy implementation on standard low cost systems, the GIS USLE model is suitable for analysing huge areas for critical places. The results can lead to more detailed studies in the risk areas thus identified or to investigations on the effect of land use changes, or can be used simply for taking care in the use of fertilisers and other chemicals in the critical agricultural areas.
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| 4. |
- Skalin, J., et al.
(författare)
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A nonlinear time series model of El Niño
- 2001
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Ingår i: Environmental modelling & software : with environment data news. - : Elsevier Ltd. - 1873-6726 .- 1364-8152. ; 16:2, s. 139-146
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Tidskriftsartikel (refereegranskat)abstract
- A smooth transition autoregressive model is estimated for the Southern Oscillation Index, an index commonly used as a measure of El Niño events. Using standard measures there is no indication of nonstationarity in the index. A logistic smooth transition autoregressive model describes the most turbulent periods in the data (these correspond to El Niño events) better than a linear autoregressive model. The estimated nonlinear model passes a battery of diagnostic tests. A generalised impulse response function indicates local instability, but as deterministic extrapolation from the estimated model converges, the nonlinear model may still be useful for forecasting the El Niño Southern Oscillation a few months ahead.
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| 5. |
- An, Li, et al.
(författare)
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Modeling agent decision and behavior in the light of data science and artificial intelligence
- 2023
-
Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 166
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Tidskriftsartikel (refereegranskat)abstract
- Agent-based modeling (ABM) has been widely used in numerous disciplines and practice domains, subject to many eulogies and criticisms. This article presents key advances and challenges in agent-based modeling over the last two decades and shows that understanding agents' behaviors is a major priority for various research fields. We demonstrate that artificial intelligence and data science will likely generate revolutionary impacts for science and technology towards understanding agent decisions and behaviors in complex systems. We propose an innovative approach that leverages reinforcement learning and convolutional neural networks to equip agents with the intelligence of self-learning their behavior rules directly from data. We call for further developments of ABM, especially modeling agent behaviors, in the light of data science and artificial intelligence.
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| 6. |
- Antosz, Patrycja, et al.
(författare)
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What do you want theory for? - A pragmatic analysis of the roles of theory in agent-based modelling
- 2023
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Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 168
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Tidskriftsartikel (refereegranskat)abstract
- There has been some discussion about agent-based modelling (ABM) and theory, particularly how ABM might facilitate theory building. However, there is confusion about the different ways they could relate and some scepticism as to whether theory is needed if one has an ABM. This paper distinguishes some of the different ways that the term “theory” is used in ABM papers in three important ABM journals: Environmental Modelling & Software, Computers, Environment and Urban Systems and the Journal of Artificial Societies and Social Simulation. Apart from the simple-minded identification of theory with mathematics, we distinguish nine different ways that theory and ABM relate. This analysis is situated with respect to some of the expectations and philosophical background behind the idea of “theory”. The paper concludes with some ways in which theory and ABM could work better together, some possible ways forward and suggests that a more cautious approach to generalisation might be more appropriate.
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| 7. |
- Ayllón, Daniel, et al.
(författare)
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Keeping modelling notebooks with TRACE : Good for you and good for environmental research and management support
- 2021
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- The acceptance and usefulness of simulation models are often limited by the efficiency, transparency, reproducibility, and reliability of the modelling process. We address these issues by suggesting that modellers (1) “trace” the iterative modelling process by keeping a modelling notebook corresponding to the laboratory notebooks used by empirical researchers, (2) use a standardized notebook structure and terminology based on the existing TRACE documentation framework, and (3) use their notebooks to compile TRACE documents that supplement publications and reports. These practices have benefits for model developers, users, and stakeholders: improved and efficient model design, analysis, testing, and application; increased model acceptance and reuse; and replicability and reproducibility of the model and the simulation experiments. Using TRACE terminology and structure in modelling notebooks facilitates production of TRACE documents. We explain the rationale of TRACE, provide example TRACE documents, and suggest strategies for keeping “TRACE Modelling Notebooks.”
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| 8. |
- Banitz, Thomas, et al.
(författare)
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Model-derived causal explanations are inherently constrained by hidden assumptions and context : The example of Baltic cod dynamics
- 2022
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 156
-
Tidskriftsartikel (refereegranskat)abstract
- Models are widely used for investigating cause-effect relationships in complex systems. However, often different models yield diverging causal claims about specific phenomena. Therefore, critical reflection is needed on causal insights derived from modeling. As an example, we here compare ecological models dealing with the dynamics and collapse of cod in the Baltic Sea. The models addressed different specific questions, but also vary widely in system conceptualization and complexity. With each model, certain ecological factors and mechanisms were analyzed in detail, while others were included but remained unchanged, or were excluded. Model-based causal analyses of the same system are thus inherently constrained by diverse implicit assumptions about possible determinants of causation. In developing recommendations for human action, awareness is needed of this strong context dependence of causal claims, which is often not entirely clear. Model comparisons can be supplemented by integrating findings from multiple models and confronting models with multiple observed patterns.
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| 9. |
- Beltramo, Agnese, et al.
(författare)
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The Global Least-cost User-friendly CLEWs Open-Source Exploratory model
- 2021
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 143
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Tidskriftsartikel (refereegranskat)abstract
- Integrated Assessment Models (IAMs) are important tools to analyse cross-sectoral interdependencies and the use of global resources. Most current tools are highly detailed and require expert knowledge and proprietary software to generate scenarios and analyse their insights. In this paper, the complementary Global Least-cost User-friendly CLEWs Open-Source Exploratory (GLUCOSE) model is presented as a highly-aggregated global IAM, open and accessible from source to solver and using the OSeMOSYS tool and the CLEWs framework. The model enables the exploration of policy measures on the future development of the integrated resource system. Thanks to its relatively simple structure, it requires low computational resources allowing for the generation of a large number of scenarios or to quickly conduct preliminary investigations. GLUCOSE is targeted towards education and training purposes by a range of interested parties, from students to stakeholders and decision-makers, to explore possible future pathways towards the sustainable management of global resources.
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| 10. |
- Berger, Uta, et al.
(författare)
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Towards reusable building blocks for agent-based modelling and theory development
- 2024
-
Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 175
-
Tidskriftsartikel (refereegranskat)abstract
- Despite the increasing use of standards for documenting and testing agent -based models (ABMs) and sharing of open access code, most ABMs are still developed from scratch. This is not only inefficient, but also leads to ad hoc and often inconsistent implementations of the same theories in computational code and delays progress in the exploration of the functioning of complex social -ecological systems (SES). We argue that reusable building blocks (RBBs) known from professional software development can mitigate these issues. An RBB is a submodel that represents a particular mechanism or process that is relevant across many ABMs in an application domain, such as plant competition in vegetation models, or reinforcement learning in a behavioural model. RBBs need to be distinguished from modules, which represent entire subsystems and include more than one mechanism and process. While linking modules faces the same challenges as integrating different models in general, RBBs are atomic enough to be more easily re -used in different contexts. We describe and provide examples from different domains for how and why building blocks are used in software development, and the benefits of doing so for the ABM community and to individual modellers. We propose a template to guide the development and publication of RBBs and provide example RBBs that use this template. Most importantly, we propose and initiate a strategy for community -based development, sharing and use of RBBs. Individual modellers can have a much greater impact in their field with an RBB than with a single paper, while the community will benefit from increased coherence, facilitating the development of theory for both the behaviour of agents and the systems they form. We invite peers to upload and share their RBBs via our website - preferably referenced by a DOI (digital object
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| 11. |
- Blanco Penedo, Isabel
(författare)
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To what extent is climate change adaptation a novel challenge for agricultural modellers?
- 2019
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Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 120
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Tidskriftsartikel (refereegranskat)abstract
- Modelling is key to adapting agriculture to climate change (CC), facilitating evaluation of the impacts and efficacy of adaptation measures, and the design of optimal strategies. Although there are many challenges to modelling agricultural CC adaptation, it is unclear whether these are novel or, whether adaptation merely adds new motivations to old challenges. Here, qualitative analysis of modellers' views revealed three categories of challenge: Content, Use, and Capacity. Triangulation of findings with reviews of agricultural modelling and Climate Change Risk Assessment was then used to highlight challenges specific to modelling adaptation. These were refined through literature review, focussing attention on how the progressive nature of CC affects the role and impact of modelling. Specific challenges identified were: Scope of adaptations modelled, Information on future adaptation, Collaboration to tackle novel challenges, Optimisation under progressive change with thresholds, and Responsibility given the sensitivity of future outcomes to initial choices under progressive change.
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| 12. |
- Blennow, Kristina
(författare)
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Simulating wind disturbance impacts on forest landscapes: Tree-level heterogeneity matters
- 2014
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Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 51, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Wind is the most detrimental disturbance agent in Europe's forest ecosystems. In recent years, disturbance frequency and severity have been increasing at continental scale, a trend that is expected to continue under future anthropogenic climate change. Disturbance management is thus increasingly important for sustainable stewardship of forests, and requires tools to evaluate the effects of management alternatives and climatic changes on disturbance risk and ecosystem services. We here present a process-based model of wind disturbance impacts on forest ecosystems, integrated into the dynamic landscape simulation model iLand. The model operates at the level of individual trees and simulates wind disturbance events iteratively, i.e., dynamically accounting for changes in forest structure and newly created edges during the course of a storm. Both upwind gap size and local shelter from neighboring trees are considered in this regard, and critical wind speeds for uprooting and stem breakage are distinguished. The simulated disturbance size, pattern, and severity are thus emergent properties of the model. We evaluated the new simulation tool against satellite-derived data on the impact of the storm Gudrun (January 2005) on a 1391 ha forest landscape in south central Sweden. Both the overall damage percentage (observation: 21.7%, simulation: 21.4%) as well as the comparison of spatial damage patterns showed good correspondence between observations and predictions (prediction accuracy: 60.4%) if the full satellite-derived structural and spatial heterogeneity of the landscape was taken into account. Neglecting within-stand heterogeneity in forest conditions, i.e., the state-of-the-art in many stand-level risk models, resulted in a considerable underestimation of simulated damage, supporting the notion that tree-level complexity matters for assessing and modeling large-scale disturbances. A sensitivity analysis further showed that changes in wind speed and soil freezing could have potentially large impacts on disturbed area and patch size. The model presented here is available as open source. It can be used to study the effects of different silvicultural systems and future climates on wind risk, as well as to quantify the impacts of wind disturbance on ecosystem services such as carbon sequestration. It thus contributes to improving our capacity to address changing disturbance regimes in ecosystem management. (C) 2013 Elsevier Ltd. All rights reserved.
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| 13. |
- Bravo, Giangiacomo, et al.
(författare)
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Alternative scenarios of green consumption in Italy : An empirically grounded model
- 2013
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 47, s. 225-234
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Tidskriftsartikel (refereegranskat)abstract
- Any transition towards a more environmentally sustainable world will strongly depend on people’swillingness to adopt the best available practices. We present here the Consumption Italy (CITA) model, anempirically grounded agent-based model designed to represent household consumption in Italy and toestimate the related greenhouse gas emissions under different environmental policy scenarios. Weexplored the effect of a price increase for high impact goods and services (e.g., because of the intro-duction carbon taxes) and of a change of agents’ environmental concern (e.g., because of informationcampaigns). We found that both kind of actions can orient people consumption in the desired direction.However, their target and intensity should be carefully calibrated to produce significant effects at anacceptable cost.
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| 14. |
- Bruce, Louise C, et al.
(författare)
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A multi-lake comparative analysis of the General Lake Model (GLM) : Stress-testing across a global observatory network
- 2018
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 102, s. 274-291
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Tidskriftsartikel (refereegranskat)abstract
- The modelling community has identified challenges for the integration and assessment of lake models due to the diversity of modelling approaches and lakes. In this study, we develop and assess a one-dimensional lake model and apply it to 32 lakes from a global observatory network. The data set included lakes over broad ranges in latitude, climatic zones, size, residence time, mixing regime and trophic level. Model performance was evaluated using several error assessment metrics, and a sensitivity analysis was conducted for nine parameters that governed the surface heat exchange and mixing efficiency. There was low correlation between input data uncertainty and model performance and predictions of temperature were less sensitive to model parameters than prediction of thermocline depth and Schmidt stability. The study provides guidance to where the general model approach and associated assumptions work, and cases where adjustments to model parameterisations and/or structure are required.
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| 15. |
- Börjesson Rivera, Miriam, 1978-, et al.
(författare)
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Including second order effects in environmental assessments of ICT
- 2014
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 56, s. 105-115
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Tidskriftsartikel (refereegranskat)abstract
- Information and Communication Technology (ICT) can have both negative and positive impacts on the environment. Immediate negative environmental impacts arise due to the production, use and disposal of ICT products, while positive effects can arise because ICT products and services replace other products. Other, more indirect consequences of introducing new technologies include e.g. that money saved by reducing costs due to ICT-induced energy efficiency, is being used in consumption of other goods and services that also need energy in their production. Such effects are examined within different disciplines under headings such as rebound effects, indirect effects, second order effects and ripple effects. This paper presents a review and discussion of different second order effects that can be linked to ICT usage in general, using e-commerce as an example. This is a first necessary step in developing methods which include second order effects when analysing the environmental impacts of ICT.
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| 16. |
- Carlsen, H., et al.
(författare)
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Choosing small sets of policy-relevant scenarios by combining vulnerability and diversity approaches
- 2016
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Ingår i: Environmental Modelling & Software. - : Elsevier. - 1364-8152 .- 1873-6726. ; 84, s. 155-164
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Tidskriftsartikel (refereegranskat)abstract
- Computer simulation models can generate large numbers of scenarios, far more than can be effectively utilized in most decision support applications. How can one best select a small number of scenarios to consider? One approach calls for choosing scenarios that illuminate vulnerabilities of proposed policies. Another calls for choosing scenarios that span a diverse range of futures. This paper joins these two approaches for the first time, proposing an optimization-based method for choosing a small number of relevant scenarios that combine both vulnerability and diversity. The paper applies the method to a real case involving climate resilient infrastructure for three African river basins (Volta, Orange and Zambezi). Introducing selection criteria in a stepwise manner helps examine how different criteria influence the choice of scenarios. The results suggest that combining vulnerability- and diversity-based criteria can provide a systematic and transparent method for scenario selection.
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| 17. |
- Chopin, Pierre
(författare)
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Modelling agricultural changes and impacts at landscape scale: A bibliometric review
- 2019
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Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 122
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the range of approaches available for assessing the impacts of agricultural changes at landscape scale is important when addressing local to global issues. Using a topic modelling approach, we reviewed the literature on impact modelling of agricultural landscapes. A search in Web of Science using the keywords model, agricultural systems and landscape yielded 1,975 hits, of which 514 papers met our selection criteria. The most salient terms fell within six groups: change, scale, pollution, biodiversity, practices and terms on biophysical/regulatory conditions. We identified four main topics: water quality, water quantity/energy crops, biodiversity and Integrated Assessment. Water management issues were more likely to be covered in North American researches, while issues related to Integrated Assessment were mainly covered in European studies. We found no relationship between topic and model type. We conclude that future integrated studies should consider the diversity of agricultural systems in governance of water and biodiversity issues.
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| 18. |
- Coucheney, Elsa
(författare)
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Accuracy, robustness and behavior of the STICS soil-crop model for plant, water and nitrogen outputs: Evaluation over a wide range of agro-environmental conditions in France
- 2015
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Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 64, s. 177–190-
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Tidskriftsartikel (refereegranskat)abstract
- Soil-crop models are increasingly used as predictive tools to assess yield and environmental impacts of agriculture in a growing diversity of contexts. They are however seldom evaluated at a given time over a wide domain of use. We tested here the performances of the STICS model (v8.2.2) with its standard set of parameters over a dataset covering 15 crops and a wide range of agropedoclimatic conditions in France. Model results showed a good overall accuracy, with little bias. Relative RMSE was larger for soil nitrate (49%) than for plant biomass (35%) and nitrogen (33%) and smallest for soil water (10%). Trends induced by contrasted environmental conditions and management practices were well reproduced. Finally, limited dependency of model errors on crops or environments indicated a satisfactory robustness. Such performances make STICS a valuable tool for studying the effects of changes in agro-ecosystems over the domain explored. (C) 2014 Elsevier Ltd. All rights reserved.
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| 19. |
- Coucheney, Elsa, et al.
(författare)
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Evaluating the precision of eight spatial sampling schemes in estimating regional means of simulated yield for two crops
- 2016
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Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 80, s. 100-112
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Tidskriftsartikel (refereegranskat)abstract
- We compared the precision of simple random sampling (SimRS) and seven types of stratified sampling (StrRS) schemes in estimating regional mean of water-limited yields for two crops (winter wheat and silage maize) that were simulated by fourteen crop models. We found that the precision gains of StrRS varied considerably across stratification methods and crop models. Precision gains for compact geographical stratification were positive, stable and consistent across crop models. Stratification with soil water holding capacity had very high precision gains for twelve models, but resulted in negative gains for two models. Increasing the sample size monotonously decreased the sampling errors for all the sampling schemes. We conclude that compact geographical stratification can modesty but consistently improve the precision in estimating regional mean yields. Using the most influential environmental variable for stratification can notably improve the sampling precision, especially when the sensitivity behavior of a crop model is known.
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| 20. |
- Coucheney, Elsa, et al.
(författare)
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The implication of input data aggregation on up-scaling soil organic carbon changes
- 2017
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Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 96, s. 361-377
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Tidskriftsartikel (refereegranskat)abstract
- In up-scaling studies, model input data aggregation is a common method to cope with deficient data availability and limit the computational effort. We analyzed model errors due to soil data aggregation for modeled SOC trends. For a region in North West Germany, gridded soil data of spatial resolutions between 1 km and 100 km has been derived by majority selection. This data was used to simulate changes in SOC for a period of 30 years by 7 biogeochemical models. Soil data aggregation strongly affected modeled SOC trends. Prediction errors of simulated SOC changes decreased with increasing spatial resolution of model output. Output data aggregation only marginally reduced differences of model outputs between models indicating that errors caused by deficient model structure are likely to persist even if requirements on the spatial resolution of model outputs are low. (C)2017 Elsevier Ltd. All rights reserved.
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| 21. |
- Dimberg, Peter H., 1985-, et al.
(författare)
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Probabilities of monthly median chlorophyll-a concentrations in subarctic, temperate and subtropical lakes
- 2013
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Ingår i: Environmental Modelling & Software. - : Elsevier. - 1364-8152 .- 1873-6726. ; 41, s. 199-209
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Tidskriftsartikel (refereegranskat)abstract
- High concentrations of chlorophyll-a (chl-a) during summer are by definition a common problem in eutrophicated lakes. Several models have been designed to predict chl-a concentrations but are unable to estimate the probability of predicted concentrations or concentration spans during subsequent months. Two different methods were developed to compute the probabilities of obtaining a certain chl-a concentration. One method is built on discrete Markov chains and the other method on a direct relationship between median chl-a concentrations from two months. Lake managers may use these methods to detect and counteract the risk of high chl-a concentrations and algal blooms during coming months. Both methods were evaluated and applied along different scenarios to detect the probability to exceed chl-a concentration in different coming months. The procedure of computing probabilities is strictly based on general statistics which means that neither method is constrained for chl-a but can also be used for other variables. A user-friendly software application was developed to facilitate and extend the use of these two methods.
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| 22. |
- Domercq, Maria del Prado, et al.
(författare)
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The Full Multi : An open-source framework for modelling the transport and fate of nano- and microplastics in aquatic systems
- 2022
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 148
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Tidskriftsartikel (refereegranskat)abstract
- We present a freely available open-source modelling framework to explore environmental transport and fate of nano-and microplastics in aquatic systems. The “Full Multi” models 1) fragmentation of plastic into a predefined set of size classes, 2) speciation of plastic particles between pristine, heteroaggregated, biofouled, and biofouled & heteroaggregated species, 3) dynamic vertical exchange between water layers and sediment of a freshwater system, and 4) horizontal particle transport by eddy diffusion and advective flow. The Full Multi framework relates emission rates to environmental exposure concentrations while considering the intrinsic properties of plastic particles and variable environmental system properties. The model can be applied to analyse scenarios with different process descriptions, plastic types, emission routes and environmental parameters for hypothesis generation, to identify dominant fate processes, and in hazard and risk assessment. Here, we introduce and illustrate the framework by modelling plastic particles with a range of densities in a generic flowing river system.
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| 23. |
- Ekström, Hanna, et al.
(författare)
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Modelling forests as social-ecological systems : A systematic comparison of agent-based approaches
- 2024
-
Ingår i: Environmental Modelling and Software. - 1364-8152 .- 1873-6726. ; 175
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Forskningsöversikt (refereegranskat)abstract
- The multifunctionality of forest systems calls for appropriately complex modelling approaches to capture social and ecosystem dynamics. Using a social-ecological systems framework, we review the functionality of 31 existing agent-based models applied to managed forests. Several applications include advanced cognitive and emotional decision-making, crucial for understanding complex sustainability challenges. However, far from all demonstrate representation of key elements in a social-ecological system like direct interactions, and dynamic representations of social and ecological processes. We conclude that agent-based approaches are adequately complex for simulating both social and ecological subsystems, but highlight three main avenues for further development: i) robust methodological standards for calibration and validation of agent-based approaches; ii) modelling of agent learning, adaptive governance and feedback loops; iii) coupling to ecological models such as dynamic vegetation models or species distribution models. We round-off by providing a set of questions to support social-ecological systems modelling choices.
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| 24. |
- Elofsson, Katarina, et al.
(författare)
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Cost-efficient climate policies for interdependent carbon pools
- 2018
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Ingår i: Environmental Modelling & Software. - : Elsevier. - 1364-8152 .- 1873-6726. ; 101, s. 86-101
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to investigate cost-effective climate policy instruments for bioenergy and timber, adapted to the impacts on interdependent forest carbon pools, and applied in the EU climate policy to 2050. We develop a discrete time dynamic model including forest carbon pools in biomass, soil, and products, as well as fossil fuel consumption. The analytical results show that the optimal taxes on forest products depend on the growth in the respective carbon pool. The application to the EU 2050 climate policy for emission trading shows that total costs for target achievement can be reduced by 33 percent if all carbon pools are included, and the carbon tax on fossil fuel can be reduced by 50 percent. Optimal taxes on forest products differ among countries and over time depending on the potential for increased carbon sequestration over the planning period. (C) 2017 The Authors.
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| 25. |
- Frostell, Björn M., et al.
(författare)
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Modeling both direct and indirect environmental load of purchase decisions : a web-based tool addressing household metabolism
- 2015
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 71, s. 138-147
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Tidskriftsartikel (refereegranskat)abstract
- Consumer awareness is continuously increasing towards pro-environmental behavior. Thus, we developed a web-based environmental feedback tool EcoRunner, which is designed for Swedish households aiming at increasing the awareness in a more pro-environmental direction. The conceptual model of EcoRunner has been developed based on top-down and bottom-up approaches connecting economic activities within a household to environmental pressures (both direct and indirect). In addition, the development of the tool includes a multi-level model aiming at better tailor-made advice to consumers. In this paper, we examine the EcoRunner tool with average single Swedish household expenditures as well as explore options for reductions and systems effects. Analysis shows that food and non-alcoholic beverages, fuel for personal transport (e.g. car) and air transports have significant environmental pressures. In addition, this study suggests that EcoRunner could be used in education systems as an environmental feedback tool to enlighten consumers motivation and change consumption patterns.
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