| 1. |
- Belanger, N, et al.
(författare)
-
Simulation of soil chemistry and nutrient availability in a forested ecosystem of southern Quebec - I. Reconstruction of the time-series files of nutrient cycling using the MAKEDEP model
- 2002
-
Ingår i: Environmental Modelling & Software. - 1364-8152. ; 17:5, s. 427-445
-
Tidskriftsartikel (refereegranskat)abstract
- The MAKEDEP model is used to reconstruct the time-series input files of deposition, forest growth, uptake and litterfall needed to run the dynamic biogeochemical model SAFE. The amounts and timing of N made available for tree growth is what determines most of the model output. In this paper, the sensitivity Of MAKEDEP to various amounts and timing of N availability, including increased supplies of N prior to air pollution assuming increased biological N-2 fixation, was assessed in a small hardwood stand of southern Quebec. The scenarios of N cycling were validated for burned and unburned conditions based on the simulated tree growth and N leaching rates as well as the model's ability to recreate the trends in atmospheric deposition of major ions in northeastern North America. The N leaching rates were calculated as the residual component of all simulated processes acting as sources and sinks of N. The N availability scenarios that subtracted/added 5 mmol m(-2) yr(-1) of NH4 in the unburned and burned conditions, respectively, recreated N leaching rates and tree biomass with the most precision. Modifying the amounts of N made available prior to air pollution was also necessary for the trees to grow to reasonable values before 1900. Historical trends of deposition were linked to the changes in the continental emissions in northeastern North America. Observational data for 30 years at the Hubbard Brook Experimental Forest, New Hampshire, showed convergent trends for most ions with the deposition trends simulated with MAKEDEP.
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| 2. |
- Belanger, N, et al.
(författare)
-
Simulation of soil chemistry and nutrient availability in a forested ecosytem of southern Quebec. Part II. Application of the SAFE model
- 2002
-
Ingår i: Environmental Modelling & Software. - 1364-8152. ; 17:5, s. 447-465
-
Tidskriftsartikel (refereegranskat)abstract
- The dynamic soil model SAFE was calibrated and validated in a small hardwood forest of southern Quebec as a function of its ability to reproduce current soil chemistry and similar pre-industrial soil conditions despite the difference in forest history. SAFE was relatively accurate for reproducing soil chemistry, but comparison of pre-industrial soil conditions between unburned and burned stands casts doubt as to its applicability at sites where specific processes may be involved in nutrient cycling, e.g. the immobilization of N by microbes. Simulated soil chemistry in the unburned zone reinforced the conclusions of a few historical studies which support the hypothesis that acid-sensitive forest sites of northeastern USA underwent significant acidification when major inputs of acidity from the atmosphere occurred, i.e. during the 1930-1980 time span. Model projections in the mineral soil suggest that a new steady-state should be reached in the 21st century assuming no harvest, but that this equilibrium is broken if timber harvesting is done. Model output also suggests that cation nutrient deficiencies could occur in the long-term, but future Al phytotoxic responses are unlikely to occur due to a relatively high projected pH. Finally, it was demonstrated that the time-series files of nutrient cycling should be prepared with care as they can be the source of some abnormalities in model calibration.
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| 3. |
- Parker, P, et al.
(författare)
-
Progress in integrated assessment and modelling
- 2002
-
Ingår i: Environmental Modelling & Software. - 1364-8152. ; 17:3, s. 209-217
-
Tidskriftsartikel (refereegranskat)abstract
- Environmental processes have been modelled for decades. However. the need for integrated assessment and modeling (IAM) has,town as the extent and severity of environmental problems in the 21st Century worsens. The scale of IAM is not restricted to the global level as in climate change models, but includes local and regional models of environmental problems. This paper discusses various definitions of IAM and identifies five different types of integration that Lire needed for the effective solution of environmental problems. The future is then depicted in the form of two brief scenarios: one optimistic and one pessimistic. The current state of IAM is then briefly reviewed. The issues of complexity and validation in IAM are recognised as more complex than in traditional disciplinary approaches. Communication is identified as a central issue both internally among team members and externally with decision-makers. stakeholders and other scientists. Finally it is concluded that the process of integrated assessment and modelling is considered as important as the product for any particular project. By learning to work together and recognise the contribution of all team members and participants, it is believed that we will have a strong scientific and social basis to address the environmental problems of the 21st Century.
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| 4. |
- Forsman, Åsa, 1972-, et al.
(författare)
-
Reduced models for efficient simulation of spatially integrated outputs of one-dimensional substance transport models
- 2003
-
Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 18:4, s. 319-327
-
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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| 5. |
- Jansson, Per-Erik., et al.
(författare)
-
A coupled model of water, heat and mass transfer using object orientation to improve flexibility and functionality
- 2001
-
Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 16:1, s. 37-46
-
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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| 6. |
- 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
-
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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| 7. |
- Skalin, J., et al.
(författare)
-
A nonlinear time series model of El Niño
- 2001
-
Ingår i: Environmental modelling & software : with environment data news. - : Elsevier Ltd. - 1873-6726 .- 1364-8152. ; 16:2, s. 139-146
-
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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| 8. |
- An, Li, et al.
(författare)
-
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
-
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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| 9. |
- Antosz, Patrycja, et al.
(författare)
-
What do you want theory for? - A pragmatic analysis of the roles of theory in agent-based modelling
- 2023
-
Ingår i: Environmental Modelling & Software. - 1364-8152 .- 1873-6726. ; 168
-
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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| 10. |
- Ayllón, Daniel, et al.
(författare)
-
Keeping modelling notebooks with TRACE : Good for you and good for environmental research and management support
- 2021
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 136
-
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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| 11. |
- Banitz, Thomas, et al.
(författare)
-
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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| 12. |
- Barthel, Roland, 1967, et al.
(författare)
-
An integrated modelling framework for simulating regional-scale actor responses to global change in the water domain
- 2008
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 23:9, s. 1095-1121
-
Tidskriftsartikel (refereegranskat)abstract
- Within coupled hydrological simulation systems, taking socio-economic processes into account is still a challenging task. In particular, systems that aim at evaluating impacts of climatic change on large spatial and temporal scales cannot be based on the assumption that infrastructure, economy, demography and other human factors remain constant while physical boundary conditions change. Therefore, any meaningful simulation of possible future scenarios needs to enable socio-economic systems to react and to adapt to climatic changes. To achieve this it is necessary to simulate decision-making processes of the relevant actors in a way which is adequate for the scale, the catchment specific management problems to be investigated and finally the data availability. This contribution presents the DEEPACTOR approach for representing such human decision processes, which makes use of a multi-actor simulation framework and has similarities to agent-based approaches. This DEEPACTOR approach is embedded in DANUBIA, a coupled simulation system comprising 16 individual models to simulate Global Change impacts on the entire water cycle of the Upper Danube Catchment (Germany, 77,000 km(2)). The applicability of DANUBIA and in particular the DEEPACTOR approach for treating the socio-economic part of the water cycle in a process-based way is demonstrated by means of concrete simulation models of the water supply sector and of the domestic water users. Results from scenario simulations are used to demonstrate the capabilities and limitations of the approach. (c) 2008 Elsevier Ltd. All rights reserved.
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| 13. |
- Beltramo, Agnese, et al.
(författare)
-
The Global Least-cost User-friendly CLEWs Open-Source Exploratory model
- 2021
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 143
-
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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| 14. |
- Berger, Uta, et al.
(författare)
-
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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| 15. |
- Blanco Penedo, Isabel
(författare)
-
To what extent is climate change adaptation a novel challenge for agricultural modellers?
- 2019
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 120
-
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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| 16. |
- Blennow, Kristina
(författare)
-
Simulating wind disturbance impacts on forest landscapes: Tree-level heterogeneity matters
- 2014
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 51, s. 1-11
-
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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| 17. |
- Bravo, Giangiacomo, et al.
(författare)
-
Alternative scenarios of green consumption in Italy : An empirically grounded model
- 2013
-
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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| 18. |
- 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
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 102, s. 274-291
-
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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| 19. |
- Börjesson Rivera, Miriam, 1978-, et al.
(författare)
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Including second order effects in environmental assessments of ICT
- 2014
-
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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| 20. |
- Carlsen, H., et al.
(författare)
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Choosing small sets of policy-relevant scenarios by combining vulnerability and diversity approaches
- 2016
-
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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| 21. |
- Chen, Cheng, et al.
(författare)
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A novel multi-source data fusion method based on Bayesian inference for accurate estimation of chlorophyll-a concentration over eutrophic lakes
- 2021
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152. ; 141
-
Tidskriftsartikel (refereegranskat)abstract
- A novel multi-source data fusion method based on Bayesian inference (BIF) was proposed in this study to blend the advantages of in-situ observations and remote sensing estimations for obtaining accurate chlorophyll-a (Chla) concentration in Lake Taihu (China). Two error models (additive and multiplicative) were adopted to construct the likelihood function in BIF; the BIF method was also compared with three commonly used data fusion algorithms, including linear and nonlinear regression data fusion (LRF and NLRF) and cumulative distribution function matching data fusion (CDFF). The results showed the multiplicative error model had small normalized residual errors and was a more suitable choice. The BIF method largely outperformed the data fusion algorithms of CDFF, NLRF and LRF, with the largest correlation coefficients and smallest root mean square error. Moreover, the BIF results can capture the high Chla concentrations in the northwest and the low Chla concentrations in the east of Lake Taihu.
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| 22. |
- Chopin, Pierre
(författare)
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Modelling agricultural changes and impacts at landscape scale: A bibliometric review
- 2019
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 122
-
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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| 23. |
- Comas, J., et al.
(författare)
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Risk assessment modelling of microbiology-related solids separation problems in activated sludge systems
- 2008
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 23:10-11, s. 1250-1261
-
Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a risk assessment model for settling problems of microbiological origin in activated sludge systems (filamentous bulking, foaming and rising sludge). The aim of the model is not to diagnose microbiology-related solids separation problems with absolute certainty but to quantify in dynamic scenarios whether simulated operational procedures and control strategies lead to favourable conditions for them to arise or not. The rationale behind the model (which integrates the mechanisms of standard activated sludge models with empirical knowledge), its implementation in a fuzzy rule-based system and the details of its operation are illustrated in the different sections of the paper. The performance of the risk assessment model is illustrated by evaluating a number of control strategies facing different short-term influent conditions as well as long-term variability using the IWA/COST simulation benchmark. The results demonstrate that some control strategies, although performing better regarding operating costs and effluent quality, induce a higher risk for solids separation problems. In view of these results, it is suggested to integrate empirical knowledge into mechanistic models to increase reliability and to allow assessment of potential side-effects when simulating complex processes. (c) 2008 Elsevier Ltd. All rights reserved.
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| 24. |
- Corominas, Ll, et al.
(författare)
-
Transforming data into knowledge for improved wastewater treatment operation : A critical review of techniques
- 2018
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152. ; 106, s. 89-103
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper is to describe the state-of-the art computer-based techniques for data analysis to improve operation of wastewater treatment plants. A comprehensive review of peer-reviewed papers shows that European researchers have led academic computer-based method development during the last two decades. The most cited techniques are artificial neural networks, principal component analysis, fuzzy logic, clustering, independent component analysis and partial least squares regression. Even though there has been progress on techniques related to the development of environmental decision support systems, knowledge discovery and management, the research sector is still far from delivering systems that smoothly integrate several types of knowledge and different methods of reasoning. Several limitations that currently prevent the application of computer-based techniques in practice are highlighted.
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| 25. |
- Coucheney, Elsa
(författare)
-
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
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 64, s. 177–190-
-
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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| 26. |
- 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
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 80, s. 100-112
-
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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| 27. |
- Coucheney, Elsa, et al.
(författare)
-
The implication of input data aggregation on up-scaling soil organic carbon changes
- 2017
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 96, s. 361-377
-
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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| 28. |
- 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
-
Ingår i: Environmental Modelling & Software. - : Elsevier. - 1364-8152 .- 1873-6726. ; 41, s. 199-209
-
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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| 29. |
- Domercq, Maria del Prado, et al.
(författare)
-
The Full Multi : An open-source framework for modelling the transport and fate of nano- and microplastics in aquatic systems
- 2022
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 148
-
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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| 30. |
- Ekström, Hanna, et al.
(författare)
-
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
-
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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| 31. |
- Elofsson, Katarina, et al.
(författare)
-
Cost-efficient climate policies for interdependent carbon pools
- 2018
-
Ingår i: Environmental Modelling & Software. - : Elsevier. - 1364-8152 .- 1873-6726. ; 101, s. 86-101
-
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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| 32. |
- Engstrom, Kerstin, et al.
(författare)
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Applying Occam's razor to global agricultural land use change
- 2016
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 75, s. 212-229
-
Tidskriftsartikel (refereegranskat)abstract
- We present a parsimonious agricultural land-use model that is designed to replicate global land-use change while allowing the exploration of uncertainties in input parameters. At the global scale, the modelled uncertainty range of agricultural land-use change covers observed land-use change. Spatial patterns of cropland change at the country level are simulated less satisfactorily, but temporal trends of cropland change in large agricultural nations were replicated by the model. A variance-based global sensitivity analysis showed that uncertainties in the input parameters representing to consumption preferences are important for changes in global agricultural areas. However, uncertainties in technological change had the largest effect on cereal yields and changes in global agricultural area. Uncertainties related to technological change in developing countries were most important for modelling the extent of cropland. The performance of the model suggests that highly generalised representations of socioeconomic processes can be used to replicate global land-use change. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 33. |
- Flores, Xavier, et al.
(författare)
-
Assessing the use of activated sludge process design guidelines in wastewater treatment plant projects: A methodology based on global sensitivity analysis
- 2012
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 38, s. 50-58
-
Tidskriftsartikel (refereegranskat)abstract
- Design inputs (wastewater characteristics, operational settings, effluent requirements or safety factors, ...) need to be supplied when using activated sludge process design guidelines (ASPDG) to determine the design outputs (biological reactor volume, the dissolved oxygen demand or the different internal/external recycle flow-rates). The values of the design inputs might have strong effects on the future characteristics of the plant under study. For this reason, there is a need to determine how both design inputs and outputs are linked and how they affect wastewater treatment plant (WWTP) designs. In this paper we assess ASPDG with a methodology based on Monte Carlo (MC) simulations and Global Sensitivity Analysis (GSA). The novelty of this approach relies on working with design input and output ranges instead of single values, identifying the most influential design inputs on the different design outputs and improving the interpretation of the generated results with a set of visualization tools. The variation in these design inputs is attributed to epistemic uncertainty, natural variability as well as operator, owner and regulator decision ranges. Design outputs are calculated by sampling the previously defined input ranges and propagating this variation through the design guideline. Standard regression coefficients (SRC), cluster analysis (CA) and response surfaces (RS) are used to identify/interpret the design inputs that influence the variation on the design outputs the most. The illustrative case study uses the widely recognized Metcalf & Eddy guidelines and presents a didactic design example for an organic carbon (C) and nitrogen (N) removal pre-denitrifying activated sludge plant. Results show that the proposed GSA can satisfactorily decompose the variance of the design outputs (R-2 > 0.7): aerobic (V-AER) and anoxic (V-ANOX) volume, air demand (Q(AIR)) and internal recycle flow rate (Q(INTR)). Response surfaces are proposed to facilitate the visualization of how, when and why the design outputs may change when the most influential design inputs are modified. Finally, it is demonstrated that the proposed method is useful for process engineers providing a regional instead of a local picture of a design problem. (C) 2012 Elsevier Ltd. All rights reserved.
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| 34. |
- Frostell, Björn M., et al.
(författare)
-
Modeling both direct and indirect environmental load of purchase decisions : a web-based tool addressing household metabolism
- 2015
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 71, s. 138-147
-
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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| 35. |
- Futter, Martyn
(författare)
-
The INtegrated CAtchment model of phosphorus dynamics (INCA-P): Description and demonstration of new model structure and equations
- 2016
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 83, s. 356-386
-
Tidskriftsartikel (refereegranskat)abstract
- INCA-P is a dynamic, catchment-scale phosphorus model which has been widely applied during the last decade. Since its original release in 2002, the model structure and equations have been significantly altered during several development phases. Here, we provide the first full model description since 2002 and then test the latest version of the model (v1.4.4) in a small rural catchment in northeast Scotland. The particulate phosphorus simulation was much improved compared to previous model versions, whilst the latest sorption equations allowed us to explore the potential time lags between reductions in terrestrial inputs and improvements in surface water quality, an issue of key policy relevance. The model is particularly suitable for use as a research tool, but should only be used to inform policy and land management in data-rich areas, where parameters and processes can be well-constrained. More long-term data is needed to parameterise dynamic models and test their predictions. (C) 2016 Elsevier Ltd. All rights reserved.
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| 36. |
- Gernaey, Krist V., et al.
(författare)
-
Dynamic influent pollutant disturbance scenario generation using a phenomenological modelling approach
- 2011
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 26:11, s. 1255-1267
-
Tidskriftsartikel (refereegranskat)abstract
- Activated Sludge Models are widely used for simulation-based evaluation of wastewater treatment plant (WWTP) performance. However, due to the high workload and cost of a measuring campaign on a full-scale WWTP, many simulation studies suffer from lack of sufficiently long influent flow rate and concentration time series representing realistic wastewater influent dynamics. In this paper, a simple phenomenological modelling approach is proposed as an alternative to generate dynamic influent pollutant disturbance scenarios. The presented set of models is constructed following the principles of parsimony (limiting the number of parameters as much as possible), transparency (using parameters with physical meaning where possible) and flexibility (easily extendable to other applications where long dynamic influent time series are needed). The proposed approach is sub-divided in four main model blocks: 1) model block for flow rate generation, 2) model block for pollutants generation (carbon, nitrogen and phosphorus), 3) model block for temperature generation and 4) model block for transport of water and pollutants. The paper is illustrated with the results obtained during the development of the dynamic influent of the Benchmark Simulation Model no. 2 (BSM2). The series of simulations show that it is possible to generate a dry weather influent describing diurnal flow rate dynamics (low rate at night, high rate during day time), weekend effects (with different flow rate during weekends, compared to weekdays), holiday effects (where the wastewater production is assumed to be different for a number of weeks) and seasonal effects (with variations in the infiltration and thus also the flow rate to the WWTP). In addition, the dry weather model can be extended with a rain and storm weather generator, where the proposed phenomenological model can also mimic the "first flush" effect from the sewer network and the influent dilution phenomena that are typically observed at full-scale WWTPs following a rain event. Finally, the extension of the sewer system can be incorporated in the influent dynamics as well: the larger the simulated sewer network, the smoother the simulated diurnal flow rate and concentration variations. In the discussion, it is pointed out how the proposed phenomenological models can be expanded to other applications, for example to represent heavy metal or organic micro-pollutant loads entering the treatment plant. (C) 2011 Elsevier Ltd. All rights reserved.
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| 37. |
- Ghorbani, Amineh, et al.
(författare)
-
Self-organization in the commons : An empirically-tested model
- 2017
-
Ingår i: Environmental Modelling & Software. - : Elsevier. - 1364-8152 .- 1873-6726. ; 96, s. 30-45
-
Tidskriftsartikel (refereegranskat)abstract
- A appropriate bottom-up rule system can support the sustainability of common-pool resources such as forests and fisheries. The process that leads to the developments of such institutional settings requires the considerations of multiple social, physical, and institutional factors over long time horizons. In this paper, we present the SONICOM model as a general exploratory model of CPR systems. The model can be configured to represent different CPR systems in order to explore what kind of institutional settings result in stable systems, i.e. situations where the resource and the appropriators are in a state of well-being. We use a large-N-dataset of CPR management institutions to validate the model. The results show numerous correlations between various parameters of the system such as rule compliance, social influence and resource growth rate which help explaining the process of institutional emergence as well as unveiling the conditions under which systems are stable.
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| 38. |
- Gyllenhammar, Andreas, et al.
(författare)
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WASUBI : A GIS tool for subbasin identification in topographically complex waterscapes
- 2005
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 20:6, s. 729-736
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Tidskriftsartikel (refereegranskat)abstract
- Spatially distributed modelling is dependent on segmentation of the underlying geographic data and the model output could be improved if relevant compartments are found and used. Herein, we present a method for identifying subbasins in complex topographic waterscapes. The method first finds local troughs and then expands them over a friction surface derived from bathymetry. Friction surfaces generated by different cost growth functions were tested, and shown to give consistent results. The model is sensitive to the quality of the underlying topographic dataset and its spatial resolution. WASUBI (WAterscape SUBbasin Identification) is written in ArcView's built-in scripting language, Avenue, and distributed as a program extension. The method is easy to use, only requiring a digital elevation model (DEM) and the user to give the number of basins to be generated. The segmentation method was tested against datasets covering the Finnish Archipelago Sea and the Okavango Delta in Botswana. Test results showed that the WASUBI delineated subbasins were more enclosed than subbasins created by a semi-random delineation method. The objectives of this study was to construct and critically test algorithms for subbasin identification, based only on readily available DEM data, for use in geographic information system modelling.
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| 39. |
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| 40. |
- halide, halmar, et al.
(författare)
-
Developing a decision support system for sustainable cage aquaculture
- 2009
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152. ; 24:6, s. 694-702
-
Tidskriftsartikel (refereegranskat)abstract
- A decision support system to assist cage aquaculture managers is presented. The system enables managers to perform four essential tasks: (i) site classification, (ii) site selection, (iii) holding capacity determination, and (iv) economic appraisal of an aquaculture farm at a given site. Based on measurements of water and substrate qualities, hydrometeorology and socioeconomic factors, a cage aquaculture site is classified into three categories – poor, medium, and good. With this information, the AHP (analytical hierarchy process) tool is used to evaluate the best site from several alternatives. A simplified version of the Modelling-On growing-Monitoring (MOM), SMOM, is developed and applied to determine how much fish can be grown on site without harming the environment. The simplified model has been calibrated against MOM, compared with other carrying capacity models and validated with farm data. A break-even point–price and return on investment (ROI) are calculated using cage-holding density and volume, mean fish weight at harvest, feed conversion ratio (FCR), survival rate of seed, costs of feed, seed and cages, the interest rate on borrowed funds and the fish price. All model components are integrated seamlessly into a user-friendly interface implemented in Java® called CADS_TOOL (Cage Aquaculture Decision Support Tool). The program with a user's guide is freely available.
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| 41. |
- Hedelin, Beatrice, 1974-, et al.
(författare)
-
What's left before participatory modeling can fully support real-world environmental planning processes : A case study review
- 2021
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 143
-
Tidskriftsartikel (refereegranskat)abstract
- In environmental participatory modeling (PM), both computer and non-computer-based modeling techniques are used to aid participatory problem description, solution, and decision-making actions in environmental contexts. Although many PM case studies have been published, few efforts have sought to systematically describe and understand dominant PM processes or establish best practices for PM. As a first step, we have reviewed a random sample of environmental PM case study articles (n = 60) using a novel PM process evaluation instrument. We found that significant work likely remains for PM to fully support participatory and integrated planning processes. While PM reports systematically address knowledge integration and learning, they often neglect the facilitation of a multi-value perspective within a democratic process, and the integration across organizations within a governance system. If not reported, we suspect these aspects are also neglected in practice. We conclude with key research and practice issues for improving PM as an approach for real-world participatory planning and governance.
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| 42. |
- Hilty, Lorenz A., et al.
(författare)
-
The relevance of information and communication technologies for environmental sustainability - A prospective simulation study
- 2006
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 21:11, s. 1618-1629
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Tidskriftsartikel (refereegranskat)abstract
- Information and Communication Technologies (ICT) have relevant positive and negative impacts on environmental sustainability on various levels: First-order effects such as increasing electronic waste streams; second-order effects such as improved energy-efficiency of production; third-order effects such as a product-to-service shift in consumption or rebound effects in transport. In the simulation study described in this article, all known relevant effects on all three levels were modeled using a System Dynamics approach in combination with scenario techniques and expert consultations. The prospective study for the European Union with a time-horizon until 2020 revealed great potential for ICT-supported energy management and for a structural change towards a less material-intensive economy, but strong rebound effects in the transport sector whenever ICT applications lead to time or cost savings for transport. (c) 2006 Elsevier Ltd. All rights reserved.
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| 43. |
- Hilty, Lorenz M., et al.
(författare)
-
Modeling and evaluating the sustainability of smart solutions
- 2014
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 56, s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- Smart technologies provide diverse and promising opportunities to reduce energy demand and greenhouse gas emissions; they are increasingly expected to shift modern societies' patterns of production and consumption towards sustainability. However, the existence of a theoretical potential does not imply that every smart solution (application of a smart technology) will contribute to sustainability. Policy-makers are therefore in need of methodologies to evaluate the sustainability of smart solutions. This paper gives an overview of the current discussion in the field and the emerging methodological challenges. The challenges of assessing the direct impact of the ICT components and infrastructures are special cases of known issues in life cycle assessment methodology. The challenges of assessing indirect impacts are inherently interdisciplinary and call for integrated modelling approaches. The last two sections provide an overview of the papers assembled in this thematic issue that treat specific cases and general principles of modeling and evaluating the sustainability of smart solutions.
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| 44. |
- Hischier, Roland, et al.
(författare)
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Evaluating the sustainability of electronic media : Strategies for life cycle inventory data collection and their implications for LCA results
- 2014
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 56, s. 27-36
-
Tidskriftsartikel (refereegranskat)abstract
- This paper compares two Life Cycle Assessment (LCA) studies independently carried out to assess the environmental impacts of electronic versus print media. Although the two studies lead to the same overall conclusion for the case of a news magazine namely that the tablet version of the magazine has environmental advantages over the print version there are significant differences in the details of the LCA results. We show how these differences can be explained by differences in the methodological approaches used for life cycle inventory (LCI) modelling, in particular the use of rough average data versus the attempt to use the most specific and detailed data as possible. We conclude that there are several issues in LCA practice (at least when applied in the domain of media) that can significantly influence the results already at the LCI level: The data collection strategy used (e.g. relying on desk-based research or dismantling a given device) and the decisions made at inventory level with regard to parameters with significant geographic variability, such as the electricity mix or recycling quotas.
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| 45. |
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| 46. |
- Janssen, S., et al.
(författare)
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Defining assessment projects and scenarios for policy support: Use of ontology in Integrated Assessment and Modelling
- 2009
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1873-6726 .- 1364-8152. ; 24:12, s. 1491-1500
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Konferensbidrag (refereegranskat)abstract
- Integrated Assessment and Modelling (IAM) provides an interdisciplinary approach to support ex-ante decision-making by combining quantitative models representing different systems and scales into a framework for integrated assessment. Scenarios in IAM are developed in the interaction between scientists and stakeholders to explore possible pathways of future development. As IAM typically combines models from different disciplines, there is a clear need for a consistent definition and implementation of scenarios across models, policy problems and scales. This paper presents such a unified conceptualization for scenario and assessment projects. We demonstrate the use of common ontologies in building this unified conceptualization, e.g. a common ontology on assessment projects and scenarios. The common ontology and the process of ontology engineering are used in a case study, which refers to the development of SEAMLESS-IF, an integrated modelling framework to assess agricultural and environmental policy options as to their contribution to sustainable development. The presented common ontology on assessment projects and scenarios can be reused by IAM consortia and if required, adapted by using the process of ontology engineering as proposed in this paper. (C) 2009 Elsevier Ltd. All rights reserved.
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| 47. |
- Jansson, Torbjörn
(författare)
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Evaluating the characteristics of a non-standardised Model Requirements Analysis (MRA) for the development of policy impact assessment tools
- 2013
-
Ingår i: Environmental Modelling and Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 49, s. 53-63
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper is to provide a critical analysis of the strengths and weaknesses of a non-standardised Model Requirements Analysis (MRA) used for the purpose of developing the Sustainability Impact Assessment Tool (SIAT). By 'non-standardised' we mean not strictly following a published MRA method. The underlying question we are interested in addressing is how non-standardised methods, often employed in research driven projects, compare to defined methods with more standardised structure, with regards their ability to capture model requirements effectively, and with regards their overall usability. Through describing and critically assessing the specific features of the non-standardised MRA employed, the ambition of this paper is to provide insights useful for impact assessment tool (IAT) development. Specifically, the paper will (i) characterise kinds of user requirements relevant to the functionality and design of IATs; (ii) highlight the strengths and weaknesses of non-standardised MRA for user requirements capture, analysis and reflection in the context of IAT; (iii) critically reflect on the process and outcomes of having used a non-standardised MRA in comparison with other more standardised approaches. To accomplish these aims, we first review methods available for IAT development before describing the SIAT development process, including the MRA employed. Major strengths and weaknesses of the MRA method are then discussed in terms of user identification and characterisation, organisational characterisation and embedding, and ability to capture design options for ensuring usability and usefulness. A detailed assessment on the structural differences of MRA with two advanced approaches (Integrated DSS design and goal directed design) and their role in performance of the MRA tool is used to critique the approach employed. The results show that MRA is able to bring thematic integration, establish system performance and technical thresholds as well as detailing quality and transparency guidelines. Nevertheless the discussion points out to a number of deficiencies in application - (i) a need to more effectively characterise potential users, and; (ii) a need to better foster communication among the distinguished roles in the development process. If addressed these deficiencies, SIAT non-standardised MRA could have brought out better outcomes in terms of tool usability and usefulness, and improved embedding of the tool into conditions of targeted end-users. (C) 2013 Elsevier Ltd. All rights reserved.
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| 48. |
- Kalteh, Aman Mohammad, et al.
(författare)
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Review of the self-organizing map (SOM) approach in water resources: Analysis, modelling and application
- 2008
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152. ; 23:7, s. 835-845
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Forskningsöversikt (refereegranskat)abstract
- The use of artificial neural networks (ANNs) in problems related to water resources has received steadily increasing interest over the last decade or so. The related method of the self-organizing map (SOM) is an unsupervised learning method to analyze, cluster, and model various types of large databases. There is, however, still a notable lack of comprehensive literature review for SOM along with training and data handling procedures, and potential applicability. Consequently, the present paper aims firstly to explain the algorithm and secondly, to review published applications with main emphasis on water resources problems in order to assess how well SOM can be used to solve a particular problem. It is concluded that SOM is a promising technique suitable to investigate, model, and control many types of water resources processes and systems. Unsupervised learning methods have not yet been tested fully in a comprehensive way within, for example water resources engineering. However, over the years, SOM has displayed a steady increase in the number of applications in water resources due to the robustness of the method.
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| 49. |
- Kara, Emily L., et al.
(författare)
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Time-scale dependence in numerical simulations : Assessment of physical, chemical, and biological predictions in a stratified lake at temporal scales of hours to months
- 2012
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 35, s. 104-121
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated the predictive ability of a one-dimensional coupled hydrodynamic-biogeochemical model across multiple temporal scales using wavelet analysis and traditional goodness-of-fit metrics. High-frequency in situ automated sensor data and long-term manual observational data from Lake Mendota, Wisconsin, USA, were used to parameterize, calibrate, and evaluate model predictions. We focused specifically on short-term predictions of temperature, dissolved oxygen, and phytoplankton biomass over one season. Traditional goodness-of-fit metrics indicated more accurate prediction of physics than chemical or biological variables in the time domain. This was confirmed by wavelet analysis in both the time and frequency domains. For temperature, predicted and observed global wavelet spectra were closely related, while observed dissolved oxygen and chlorophyll fluorescence spectral characteristics were not reproduced by the model for key time scales, indicating that processes not modeled may be important drivers of the observed signal. Although the magnitude and timing of physical and biological changes were simulated adequately at the seasonal time scale through calibration, time scale-specific dynamics, for example short-term cycles, were difficult to reproduce, and were relatively insensitive to the effects of varying parameters. The use of wavelet analysis is novel to aquatic ecosystem modeling, is complementary to traditional goodness-of-fit metrics, and allows for assessment of variability at specific temporal scales. In this way, the effect of processes operating at distinct temporal scales can be isolated and better understood, both in situ and in silico. Wavelet transforms are particularly well suited for assessment of temporal and spatial heterogeneity when coupled to high-frequency data from automated in situ or remote sensing platforms.
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| 50. |
- Kauffeldt, Anna, et al.
(författare)
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Technical review of large-scale hydrological models for implementation in operational flood forecasting schemes on continental level
- 2016
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 75, s. 68-76
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Forskningsöversikt (refereegranskat)abstract
- Uncertainty in operational hydrological forecast systems forced with numerical weather predictions is often assessed by quantifying the uncertainty from the inputs only. However, part of the uncertainty in modelled discharge stems from the hydrological model. A multi-model system can account for some of this uncertainty, but there exists a plethora of hydrological models and it is not trivial to select those that fit specific needs and collectively capture a representative spread of model uncertainty. This paper provides a technical review of 24 large-scale models to provide guidance for model selection. Suitability for the European Flood Awareness System (EFAS), as example of an operational continental flood forecasting system, is discussed based on process descriptions, flexibility in resolution, input data requirements, availability of code and more. The model choice is in the end subjective, but this review intends to objectively assist in selecting the most appropriate model for the intended purpose.
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