A Garp3 model of environmental sustainability in the River Mesta (Bulgaria)


We present a qualitative model of sustainable development issues in the River Mesta, Bulgaria. Following a standardized framework for conceptual description of QR case studies, we have organized our expert knowledge about biological and physical processes in the stream as well as impacts of external influences like pollution, erosion, and water abstraction. We present essential background about the modelled system, and describe how available knowledge was encapsulated into QR knowledge structures including model fragments and scenarios. Finally, we present simulation output based on this knowledge and discuss how this output contributes to understanding factors affecting sustainability of the River Mesta system. Introduction To realize the European Union’s Strategey for Sustainable Development (SSD; European Commission 2001), citizens must become more educated about factors that affect sustainable development (SD). Qualitative reasoning (QR) has proven effective in educational settings as a means to educate about cause and effect ({Bredeweg, 2003 #4184}). This paper contributes to the objectives of the SSD, in the context of the NaturNet-Redime project, by presenting a QR model about an SD case study. This QR model will become part of a curriculum aimed at teaching concepts of sustainability, including the impacts of biological, physical, and chemical processes on human well-being (Nuttle et al. 2006). The basic objective of this modelling project is to transfer expert knowledge (contained in a QR model) about processes affecting sustainability to stakeholders, decision makers, and citizens. This paper builds from Uzunov (2006), which presented preliminary progress in organizing qualitative knowledge about the River Mesta system using a “structured approach to qualitative modelling” (Bredeweg et al., in press). Here, we update that information based on the actual content of the implemented model. We begin by presenting essential background on the River Mesta system and a list of model goals. Next, we describe the most and insightful model fragments and scenarios that contribute to fulfilling these goals. We then present simulation results based on these scenarios, highlighting the most relevant behaviour paths. Finally, we discuss how these simulation results contribute to our model goals, in the context of supporting the SSD’s educational objectives. Model System Varadinova (2006) describes the basic features of the River Mesta. The region is recognized as economically under-developed, with high unemployment. Regional development plans focus on intensifying economic activities based mostly on natural features of the region. This includes further development and diversification of tourism; modernizing and intensifying agriculture and forestry; increasing energy production from hydropower; construction of new roads and streets, and enhancing infrastructure like sewage systems, wastewater treatment plants, and domestic waste landfills. All of these activities need more water than the River Mesta watershed can supply, potentially leading to conflicts between users. State and local authorities are faced with difficult solutions how meet these competing demands. Reconciliation of these conflicts requires finding of sustainable solutions and appropriate environmental and/or ecosystem health indicators, in addition to the economic and/or social ones usually taken into account. One of the indicative parameters of aquatic ecosystem health is the amount of dissolved oxygen (DO) in the water. Oxygen is an essential component for all living organisms in the aquatic ecosystem. All water bodies contain some amount of DO due to diffusion from the atmosphere. Normally there is a dynamic equilibrium between inputs and outputs of DO due to the biological processes of oxygen production and consumption. Water pollution, abstraction, erosion and other human activities can disrupt this balance, worsening ecosystem health and decreasing sustainable uses of ecosystem services. Based on these factors, being able to discriminate between anthropogenic and natural fluctuations of DO is potentially of great importance for decision making about sustainable and integrated management of aquatic ecosystems. QR provides a modelling paradigm that allows explicit representation of the various processes that interact in a water body to affect DO (Bredeweg and Struss 2003). Furthermore, the ontology provided by QR facilitates education about these processes, which will be useful for explanation to decision makers and stakeholders—those people who have a vested interest in the outcome of sustainable decisions. Figure 1. River Mesta concept map

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@inproceedings{Nakova2007AGM, title={A Garp3 model of environmental sustainability in the River Mesta (Bulgaria)}, author={Elena Nakova and Bert Bredeweg and Paulo Salles and Tim Nuttle}, year={2007} }