Computer Engineering Commons^™

Analyzing Regime Shifts In Agent-Based Models With Equation-Free Analysis, Romina Martin, Spencer Angus Thomas

International Congress on Environmental Modelling and Software

Conventional tools to analyze regime shifts in ecosystems, e.g. stable state and bifurcation analyses, are increasingly adapted to investigate social-ecological systems. The challenge lies in combining the analysis of system dynamics with the analysis of transient dynamics emerging from adaptive and heterogeneous agents. A typical question is, to which extent do micro level interactions contribute to a macro level outcome? We demonstrate the application of a new tool, equation-free analysis, for evaluating the state space from an agent-based model (ABM) on lake restoration. By sidestepping the requirement of an equation describing a systems macroscopic behavior, equation free analysis enables system …

Numerical Simulation Of A New Three-Dimensional Non-Hydrostatic Model, Ling Kang, Shangwen Jiang

International Congress on Environmental Modelling and Software

The hydrostatic pressure assumption has been widely applied in hydrodynamic numerical simulation in rivers and lakes, but it has been found inappropriate in various cases where the vertical acceleration is significant. To this end, this paper proposes a new three-dimensional, non-hydrostatic hydrodynamic model. Based on Navier-Stokes equations with the σ-coordinate transformation, rectangular grid is adopted as the approximation of the study region. For numerical solution, the process includes two steps, the estimated step and the modified step. The FDM is adopted to derive the discretization of the governing equations, and the θ method is employed for equations solution. A numerical …

Using Multi-Objective Optimization To Support Urban Planning, Jonas Schwaab, Kalyanmoy Deb, Erik Goodman, Sven Lautenbach, Maarten Van Strien, Adrienne Grêt-Regamey

International Congress on Environmental Modelling and Software

Globally urban growth destroys fertile soils and endangers food security. Fertile soils are often located in the vicinity of existing urban areas. Thus, preserving high-quality soils often conflicts with the objective of compact city development. Urban planners have to account for both of these and many other objectives and react to political decisions which put a higher weight on some of them. In addition, urban planners have to deal with uncertain projections on population growth and the demand for housing. We used a multi-objective evolutionary algorithm to show for a case study region in Switzerland how robust urban growth patterns …

A Study Of Non-Point Source Pollution Reduction Of Tea Garden In Taiwan Feitsui Reservoir Watershed, Chia-Chun Ho, Jen-Yang Lin

International Congress on Environmental Modelling and Software

The water quality of Feitsui Reservoir, which located in the north of Taiwan, has long been maintained mesotrophic to oligotrophic status. However, the pass rate of total phosphorous (TP) concentration of those three upstream streams, Jingualiao River, Daiyujue River, and Beishi River, have not reached 100% compliance with Class A Standard of water quality from Taiwan EPA. The main source of TP is from agriculture fertilizer, especially from the tea garden. In order to remove the non-point sources pollution, the bioretention was adopted and established at the outlet of the runoff drainage path of tea garden. The tea garden area …

Application Of The Swat Model To Investigate Surface Runoff And Nitrate Flux Towards The Mediterranean Sea: Case Of The Tafna Catchment (North-West Of Africa), Amin Zettam, Amina Taleb, Sabine Sauvage, José Miguel Sanchez-Perez, Laurie Boithias, Nouria Belaidi

International Congress on Environmental Modelling and Software

Water in North-West of Africa is an increasingly valuable resource due to high competition between agriculture, industry and drinking water supply, accentuated by frequent drought conditions in a semi-arid climate. For a few decades, the demographic explosion, the development of agriculture and industry, and the building of water infrastructures (dams) have modified the water fluxes and the biogeochemical cycle of nitrogen towards an increased production of nitrates in waters. The objectives of this study are to propose a modelling approach to quantify the contribution of the Tafna coastal watershed (North-West of Africa) to the flux of nitrates into the Mediterranean …

Implication Of Density-Dependent Flow On Numerical Modelling Of Sw-Gw Interactions, Sina Alaghmand, Philip Brunner, Thomas Graf, Craig Simmons

International Congress on Environmental Modelling and Software

With the growing interest in the last decades in the modelling of hydrogeological processes involved in the water resources management, it has been recognized that the assumption of constant-properties water is no longer adequate in the analysis and simulation of the flow considered in these cases. In recent years, many studies used simplistic approaches that may not represent the aquifer flow dynamics realistically by not accounting for changing fluid density. This study explore the importance of understanding the impact of density-dependent flow on SW-GW interactions. To this aim two synthetic models was developed at large and small scales and various …

The Perceived Value Of A Collaborative Platform Promoting A Rivercare Community About The Effects Of Riverine Management, Vivian Juliette Cortes Arevalo, Robert Jan Den Haan, Fedor Baart, Mascha Van Der Voort, Suzanne Hulscher

International Congress on Environmental Modelling and Software

Riverine measures such as longitudinal training dams, stream restoration, side channels and sediment management are implemented in the Netherlands. Measures aim at accommodating high-water levels while improving the spatial quality of the surroundings. Identifying the actual effects of river measures requires to effectively facilitate the access, discussion and sharing of knowledge between actors of different disciplines or backgrounds. The communication project of RiverCare offers a web-collaborative platform to support knowledge sharing between experts and non-experts actors. RiverCare is a large Dutch research programme studying the riverine and integrated effects of measures towards more collaborative and sustainable management. The knowledge of …

Analysing Urban Development With Decision Tree Based Cellular Automata. Toward An Automatic Transition Rules Creation Process, V. Judge, O. Klein, J. P. Antoni

International Congress on Environmental Modelling and Software

Land use evolution study has become a major stake in urban planning. One of the main challenge is to understand processes behind. Various studies highlight the usefulness of simulation tools in research focusing on land use change. Among simulation tools, Cellular Automata (CA) are well adapted with their geometric properties and potential to identify emerging spatial structures and processes. The transition rules definition is a key step of these CA-based simulations. Indeed, “in the context of urban systems, we often have no idea what the “right” rules are” (Torrens, 2011). In our approach “right rules” should be thematically interpretable rules …

Nitrogen Cascade At The Landscape Scale: Modelling The Effect Of Climate, Soils And Agriculture On Direct And Indirect Nitrogen Emissions In Contrasted Rural Sites, Cyril Benhamou, Patrick Durand, Jordy Salmon-Monviola, Christophe Flechard, Sylvain Ferrant, Anne Probst, Josette Garnier, Gaëlle Tallec, Pierre Cellier, Laurène Casal, Juliette Anglade, Camille Chambon, Jean-Louis Drouet

International Congress on Environmental Modelling and Software

In rural landscapes the nitrogen cascade, i.e. the way reactive nitrogen transforms and transfers into, within and out of the agro-ecosystems depends on farm management, landscape structure and their interactions with soil types, topography, climate and hydrology. While NO₃^- emissions to water bodies are frequently measured and modeled at the catchment level, this is rarely the case for NH₃ and N₂O emissions. However on one hand NH₃ emissions to the atmosphere in intensive livestock production areas may be of the same order of magnitude as NO₃^- emissions to water. On the other …

Assessing The Performance Of A Spatially Distributed Soil Erosion And Sediment Delivery Model For Han River Basin Of South Korea, Chung Gil Jung, Ji Wan Lee, So Ra Ahn, Seong Joon Kim

International Congress on Environmental Modelling and Software

When assessing the total sediment yield of a watershed through sediment transport from soil erosion process, the ratio of sediment delivery is a critical and uncertain factor during modelling. This study is to estimate watershed scale sediment yield with the evaluation of RUSLE (Revised Universal Soil Loss Equation) rain erosivity R factor for 15 years (2000 ~ 2014) using 1 minute data from 16 rainfall gauging stations in Han River basin (34,148 km²) of South Korea. The average R value in this study was evaluated as 4,708 MJ/ha mm/year with range of 1,652 ~ 10,143 MJ/ha mm/year while …

Hierarchical Hybrid Modelling, Reza Hesan, Erik Pruyt

International Congress on Environmental Modelling and Software

Environmental systems are complex systems. They are composed of many heterogeneous agents interacting in nonlinear ways within environment. Consequently, capturing the dynamics and understanding these systems are often similarly complex. To understand complex systems, hierarchy theory proposes to decompose these systems to levels (vertical structures) and subsystems (horizontal structures). Hierarchical perspectives could help in understanding complex environmental systems. However, existing modeling platforms lack of an appropriate abstraction which supports hierarchical structuring of systems. Consequently, the application of hierarchy theory has been limited to observational purposes. In this paper, we present a hierarchical simulation platform and a software package developed to …

Comparing State-Of-The-Art Multi-Objective Evolutionary Algorithms For Water Allocation Under Different Climate Scenarios, Dan Yan, Fulco Ludwig, He Qing Huang, Saskia E. Werners

International Congress on Environmental Modelling and Software

Water allocation is facing profound challenges due to increasing climate uncertainties. To deal with these uncertainties, we developed a modelling framework linking decision making on water allocation and multi-objective evolutionary search. The framework aims to assess how nine different multi-objective evolutionary algorithms (MOEAs) perform in identifying robust water allocation plans for large rivers. It was applied to the Pearl River basin in China to allocate sufficient flow into the delta to reduce salt intrusion in the dry season under current and future climate conditions. Results show all the MOEAs perform well in sustaining required discharge at two gauge stations from …

Identification Of Critical Source Areas Of Nutrient Loads Using Swat Model: Case Study, Zrebar Lake Watershed, Iran, S. Imani, M. Delavar, M. H. Niksokhan

International Congress on Environmental Modelling and Software

Entrance of nutrients and sediments to water bodies (i.e. Lakes) originating from watersheds is a serious problem in the Iran and other countries. So, the identification of critical source areas (CSAs) of pollutants in terms of watershed hydrologic units is extremely important for effective management of pollutant sources and implementation of best management practices for better protection of water quality. The main objective of this study was to identify and evaluate critical source areas (CSAs) of Nutrient loads using an integrated modeling approach. For this, Soil and Water Assessment Tool (SWAT) was used to identify CSAs of nutrients in the …

From Research Data To Web-Based Policy Tools: User-Centered Design Techniques In The Development Of The Agmip Impacts Explorer, Joske Houtkamp, Inge La Rivière, Hugo De Groot, Sander Janssen, Arjan De Jong

International Congress on Environmental Modelling and Software

decision making through a web-based tool is a complex challenge. Research projects are generally not designed to meet the information needs of specific stakeholder groups. Furthermore, tools developed in these projects are usually intended to disseminate research data on a wide scale, not to provide answers to specific questions of these stakeholders. User-centered design techniques can guide the development process of such tools, to enhance their usefulness and thus the applicability of the research outcomes for the intended audience. We applied techniques for user requirements analysis of the Impacts Explorer tool in the AgMIP research project, which models the impacts …

Escapade To Quantify Nitrogen Losses In Territories And Assess Mitigation And Adaptation Strategies, Jean-Louis Drouet, François Laurent, Patrick Durand, Gilles Billen, Pierre Cellier, Olivier Maury, Stéphanie Potok, Philippe Faverdin, Christophe Fléchard, Josette Garnier, Armelle Guy, Catherine Hénault, Catherine Mignolet, Hervé Monod, Anne Probst, Stéphane Sorin, Gaëlle Tallec, Matthias Beekmann, Eric Ceschia, Cécile Le Gall, Thierry Morel, Gauthier Quesnel, Eric Ramat

International Congress on Environmental Modelling and Software

Agriculture is facing to the challenge of maintaining or even increasing production while limiting the use of nitrogen inputs. The introduction of mineral nitrogen in agroecosystems feeds a cascade of processes and losses to the environment at each stage of the cascade with many environmental and societal impacts (degradation of air, water and soil quality, impacts on greenhouse gas balance, biodiversity and human health…). Since classical approaches at plot or farm scale do not make possible to control all impacts, levers must also be sought at larger scales. The overall objective of the interdisciplinary project ESCAPADE (ANR-12-AGRO-0003, 2013-2017) is to …

Modelling Dynamic Social-Ecological Systems: Towards An Integrated, Multiscale Approach, Terence P. Dawson, Lorenzo Milazzo, Gary Polhill

International Congress on Environmental Modelling and Software

Social-ecological systems (SES) consist of open, coupled, complex, interactive and non-linear dynamic processes that are inherently unpredictable. SES are a form of Complex Adaptive System (CAS) in which a dynamic network of many agents (which may represent species, people, organisations, nations, etc.) are acting independently and in parallel, constantly responding to their environment and what the other agents are doing. Hence, the causal drivers of SES behaviour tend to be highly dispersed and decentralized. An important characteristic of a CAS is that they can exhibit emergent behaviour and self-organisation, phenomena that cannot be predicted directly from the properties of their …

Improving Multi-Objective Management Of Water Quality Tipping Points: Revisiting The Classical Shallow Lake Problem, Julianne Quinn, Patrick Reed, Klaus Keller

International Congress on Environmental Modelling and Software

Recent multi-objective extensions of the classical shallow lake problem are useful for exploring the conceptual and computational challenges that emerge when managing irreversible water quality tipping points. Building on this work, we explore a four objective version of the lake problem where a hypothetical town derives economic benefits from polluting a nearby lake, but at the risk of irreversibly tipping the lake into a permanently polluted state. The trophic state of the lake exhibits non-linear threshold dynamics; below some critical phosphorus (P) threshold it is healthy and oligotrophic, but above this threshold it is irreversibly eutrophic. The town must decide …

A Numerical Study Of The Lateral Hyporheic Flow About A Channels Confluence, C. Gualtieri

International Congress on Environmental Modelling and Software

Stream and pore waters continuously interact and mix within streambeds due to spatial and temporal variations in channel characteristics. This mixing is termed as hyporheic exchange and the zone where groundwater and stream water are mixing is called hyporheic zone, which can greatly affect water quality is both surface and subsurface water systems. Typical examples of hyporheic fluxes are those under bedforms, intra-meander or across point bar deposits, while the lateral and vertical hyporheic exchanges about a riverine confluence was almost never investigated.

The paper presents some results of a numerical study carried out to investigate the basic features of …

Structural Equation Modelling For Individual-Based Simulation, Kai G. Mertens, Iris Lorscheid, Matthias Meyer

International Congress on Environmental Modelling and Software

Simulation modelling and individual-based modelling in particular is widely applied to analyse socio-ecological systems (SES). However, the degree of complexity of SES and the corresponding characteristics of individual-based models challenge their analysis. In particular, the analysis might be aggravated by characteristics such as a high number of entities and parameters, interdependent relations as well as several layers of effects. In addition, the analysis has to cover sometimes multivariate simulation model outputs. Further challenges concerning the analysis of these complex models and their results are their subsequent understanding and communication, which are crucial but often neglected tasks in simulation modelling. Overall, …

Scaling Watershed Models: Modern Approaches To Science Computation With Mapreduce, Parallelization, And Cloud Optimization, Jonathan Flaishans, Meridith Fry, Trip Hook, Nelson Thurman, Jim Carleton, Shelly Thawley, Kurt Wolfe, Dirk Young, Tom Purucker

International Congress on Environmental Modelling and Software

Environmental models are products of the computer architecture and software tools available at the time of development. Scientifically sound algorithms may persist in their original state even as system architectures and software development approaches evolve and progress. Dating back to the 1980s, the EPA has developed algorithms to estimate the flux of pesticides from treated fields to neighboring water bodies. Recent development of the EPA’s Spatial Aquatic Model (SAM) has provided an opportunity to redevelop, optimize and modernize this code used for regulatory decisions. Use of profiling has indicated a number of efficiencies that could be gained by updating the …

Qualifying Agriculture In Areas Affected By Pesticide Water Pollution: An Information System To Help Water Managers In Designing And Monitoring Agro-Environmental Action Plans, F. Vernier, A. Miralles, J. P. Tonneau

International Congress on Environmental Modelling and Software

Water quality is still getting worse, despite decades of public policy attempting to reverse this decline. Agricultural activities have been identified as a main source of diffuse pollution by pesticide. Therefore, qualifying the current and future agriculture is a major concern for water managers and decision makers: pesticide products used with varying chemical contents generate transfers of pesticides to freshwaters and potentially hazardous residue. The aim of our study is to analyse key stakeholders involved in the decision process to implement environmental action plans, how they use (or not) thematic and spatial available information and to propose a helpful information …

Temporal Query Processing For Supporting Sustainable-Innovation-Policy Systems, Alfredo Cuzzocrea, Ilaria D’Elia, Antonio De Nicola, Hugo Maldini, Maria Luisa Villani

International Congress on Environmental Modelling and Software

We propose an innovative method for temporal analysis of integrated environmental scenarios aimed at supporting policy making for sustainable innovation. This requires the study of possible effects of low-carbon policies on the society and, hence, copying with a multi-disciplinary domain. In fact scenarios represent possible future states of the world under plausible conditions and different assumptions, evaluated under various perspectives, such as: energy, environment, economy and societal system. Scenarios are usually produced by independent tools (e.g., TIMES, GAINS and the Social Accounting Matrix), and once they are integrated, there is a need for new analysis techniques to cope with the …

Modeling The Flash Flood Of Cannes (Fr) With Basilisk, G. Kirstetter, S. Popinet, P.-Y. Lagrée, J. M. Fullana, C. Josserand

International Congress on Environmental Modelling and Software

We propose an open source solver to model flash floods, using the well-known shallowwater equations, in 2 dimensions. The full resolution of such equations have usually a high computational cost, so that majority of flood simulation softwares used for flood forecasting is using a simplification of this model, which is not relevant in the case of flash flood, where torrential flows are commons. To reduce drastically the cost of such 2D simulations, we propose a 2D shallow-water flow solver built with the open source code Basilisk (http://basilisk.fr/) which is using adaptive refinement on a quad-tree grid. We reproduce the flood …

Ogc Sensor Observation Service: Past, Present, Internet Of The Things, Argyris Samourkasidis, Ioannis N. Athanasiadis

International Congress on Environmental Modelling and Software

Every-day devices are being miniaturized, equipped with transducers and transformed into internet-connected sensor nodes. Above smart-devices, not only can sense their surroundings, but could also store and disseminate their observations. While Internet of the Things (IoT) introduces a new, dynamic, participatory ecosystem of decentralized and collaborative devices, intrinsic heterogeneity hinders its full realization. Diversity of smart-devices and their resulting data formats, demands for interoperable data curation solutions. Open Geospatial Consortium (OGC) has put significant work towards interoperable data interchange. Through Sensor Web Enablement (SWE) and its related service interfaces, and information models, OGC offers syntactic and semantic interoperability. Sensor Observation …

Iterative Discovery: A Method For Discovering Feasible Interventions And Targets Conjointly Using Uncertainty Visualisations, Baihua Fu, Joseph Guillaume, Tony Jakeman

International Congress on Environmental Modelling and Software

Making environmental management and policy decisions is a complex and difficult task when the problem of interest encapsulates pervasive complexity, dynamism and uncertainty. One category of environmental decision making problems may be referred to as “Planning refinements with difficult-to-define objectives”. By our definition, such problems have the following characteristics:

• a current management intervention is already in place, which is known to have limitations, none of which are considered pressing;
• there are significant uncertainties in the systems and models;
• management targets are too complex to satisfactorily explore with optimization tools;
• management targets need to be set that are dependent on what …

Ilmsweb - A Modular, Web-Based Software Platform For Integrated Environmental Modelling, Data Management And Decision Support, S. Kralisch, A. Künne, J. M. Santos, P. Selsam, C. Schwartze

International Congress on Environmental Modelling and Software

Integrated water resources management in river basins and related impact assessment of changing climate and landuse typically demand for the integration of a variety of software tools and methods. These often include data management and information systems, classification tools for deriving spatial input data from satellite or airborne imagery, GIS tools for pre-processing and integration of spatial information, hydrological simulation models and multi-criteria comparison methods. While there is a plethora of individual solutions and tools available that address these requirements, their seamless and user-friendly integration in decision support tools remains challenging. We are presenting ILMSweb, a modular, web-based software platform …

Cmfs: A Methodology To Guide The Design Of Conceptual Model Of Farmers’ Decision-Making Processes, Marion Robert, Alban Thomas, Jacques-Eric Bergez

International Congress on Environmental Modelling and Software

The agricultural research community uses languages and approaches to model farmers’ decision-making processes but does not clearly detail the steps necessary to build a decision model. We propose an original and easily applicable methodology for modelers to guide data acquisition and analysis, incorporate expert knowledge, and conceptualize decision-making processes in farming systems. It combines decision-making analysis with a modeling approach inspired by cognitive sciences and software-development methods. It is organized into four steps:

1) Problem Definition

• Specify the context and the initial research question.
• Chose the type of data to collect.

2) Case Study Selection

• Select case studies based on …

Understanding The Long-Term Increase Of Flood Risk In Regulated Rivers Through Combined Use Of Cfd, Paleo-Hydrology And Hydrological Data, Patricio Bohorquez, Fernando García-García

International Congress on Environmental Modelling and Software

This paper examines the increase of risk of flooding for a given size flood in urban areas upstream of dam as a consequence of in-channel sedimentation and silted-up reservoir over time. We selected one of the earliest gauged, dammed rivers in Spain: the Guadalquivir River. Our study combines high-resolution shallow water numerical simulations, characterization of paleoflood deposits as sedimentary sequences and botanical high-water marks, as well as hydrological instrumental data taken during large floods with return period of approximately 100 yrs. The co-existence of gauging records and in-situ imagery of water levels for more than one century allows us to …

Chemical Transformation System: Cloud Based Cheminformatic Services To Support Integrated Environmental Modeling, Kurt Wolfe, Nicholas Pope, Rajbir Parmar, Mike Galvin, Caroline Stevens, Eric Weber, Jonathan Flaishans, Tom Purucker

International Congress on Environmental Modelling and Software

Integrated Environmental Modeling (IEM) systems that account for the fate/transport of organics frequently require physicochemical properties as well as transformation products. A myriad of chemical property databases exist but these can be difficult to access and often do not contain the proprietary chemicals that environmental regulators must consider. We are building the Chemical Transformation System (CTS) to facilitate model parameterization and analysis. CTS integrates a number of physicochemical property calculators into the system including EPI Suite, SPARC, TEST and ChemAxon. The calculators are heterogeneous in their scientific methodologies, technology implementations and deployment stacks. CTS also includes a chemical transformation processing …

A Novel Sampling Approach For Efficient And Robust Uncertainty And Sensitivity Analysis Of Environmental Models, Razi Sheikholeslami, Saman Razavi

International Congress on Environmental Modelling and Software

Modern environmental models are typically characterized by a large parameter/problem space and high computational demand. These two attributes impede effective implementation of sampling-based analysis such as sensitivity and uncertainty analysis, which require running these computationally intensive models many times to adequately explore and characterize the parameter/problem space. Therefore, developing efficient sampling strategies that scale with the size of the problem, computational budget, and users’ needs is essential. In this study, we propose an efficient sequential sampling strategy, called Progressive Latin Hypercube Sampling (PLHS), which provides an increasingly improved coverage of the parameter space, while satisfying pre-specified requirements. As opposed to …