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• A holistic dynamic system model is developed to simulate soil salinity and sodicity. • Irrigation efficiency has dual role in salinity control. • Relative intensity of salinity to sodicity impacts hydraulic conductivity. • Salt tolerant crops may lead to higher salinization in the long term. • The model is used as the basis of an on-line interactive learning environment. In this research, a dynamic simulation model, SAMIMI (Sa linity/Sodicity M anagement with an I nteractive M odel I nterface), is developed for managing the effects of agricultural water use and crop choices on soil salinization and sodification, and their impacts on crop yields. SAMIMI integrates the vertical hydraulic flow, solute transport, and crop processes in feedback by a compartmental, non-linear model architecture. With its holistic integrated approach to salinity /sodicity processes, it adopts a system dynamics approach. Though it is simplified in spatial resolution, the model credibility is sufficiently evaluated with indirect structure tests and against the data by Hydrus-1D, and soil-column experiments that were conducted as part of the SAMIMI (Sa linity/Sodicity M anagement I nterdisciplinary M ulti- I nstitutional Network) project conducted in the semi-arid Konya Closed Basin of Turkey. Model analysis provide valuable insights to the role of irrigation efficiency, water quality and crop choices on soil degradation and yield losses, which are important for learning about and management of salinity/sodicity related problems: Although irrigation efficiency is desirable for water conservation purposes, it may result in higher salinity /sodicity levels because of insufficient leaching in well drained soil profiles. Salinity and sodicity have opposite effects on soil hydraulic conductivity, and while low saline irrigation water is desirable for agricultural production, under relatively high sodic conditions, it can lead to reduced hydraulic conductivity which can degrade soil characteristics to the detriment of crops. Salinity is not simply correlated with relative irrigation water consumption but with the crop salt tolerance as well. Hence, low water consuming crops with high salt tolerance can lead to over salinization, rendering the soil profiles inappropriate for cultivation of salt vulnerable crops, if not sufficiently leached before by precipitation and/or good-quality irrigation water. The model is published as a publicly available online interactive simulation tool with a fast-simulating user-friendly interface targeting researchers, students, experts, farmers and policy makers. [ABSTRACT FROM AUTHOR]

Previous experimental studies have found that people generally misperceive the basic dynamics of renewable resources, and in particular the accumulation of greenhouse gases (GHGs) in the atmosphere. The purpose of the present laboratory experiment is to find out why people misperceive the dynamics of CO2 accumulation and how misperceptions could be avoided. Using a simulator, 242 subjects were each asked to control total global emissions of CO2 to reach a given target for the stock of CO2 in the atmosphere. Consistent with previous investigations we find a strong tendency for people to overshoot the stated goal. Furthermore, our results point out that people need help to develop proper mental models of CO2 accumulation and they need motivation to reconsider inappropriate decision heuristics. Based on these results and the literature on conceptual change a new information strategy is designed. To motivate, it imposes cognitive conflict; and to facilitate new understanding, it provides simple analogies. A new test shows promising learning effects. The results have important implications for the Intergovernmental Panel on Climate Change (IPCC), governments, and media covering the climatic change issue as well as for general education. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the decision rules adopted by individuals in local communities, whose livelihoods depend on common pool resource stocks and who face the cooperation dilemma in their everyday life. For this purpose, field experiments are modeled and the model structure and output are confronted with experimental data and with the relevant theory of collective action proposed by [Ostrom, E., 1998. A behavioral approach to the rational choice theory of collective action. American Political Science Review 92 (1), 1–22.]. The field experiments analyze the cooperative action among coastal communities in Providence Island (Colombian Caribbean Sea). The simulation model is built according to the principles and methods of System Dynamics. The model formalizes the feedback causality among reputation, trust and reciprocity [Ostrom, E., 1998. A behavioral approach to the rational choice theory of collective action. American Political Science Review 92 (1), 1–22.]. Moreover, based on the payoff structure and treatments used in the experiments, it considers other behavioral factors such as temptation to free ride, profit maximization, awareness and risk perception of the individuals in feedback perspective. Model behavior replicates the patterns in the experimental data and is highly sensitive to reciprocity and free-riding behavior. It reveals path-dependent characteristic to the initial trust of the individuals in the group. The variables and decision rules built into the model structure provide the basis for a dialogue between the theories of collective action and future experimental designs to test and improve such theories. [Copyright &y& Elsevier]

Provides information on a study that analyzed potential long-term environmental problems of the Southeastern Anatolian Project related to water resources, land use, land degradation, agricultural pollution and demography using a system dynamics approach. Scope and purpose of system dynamics model; Methodology of the study; Conclusion.

Highlights: [•] A coupled land use dynamics and surface/subsurface hydrologic model is developed. [•] Coupling of the two models is through the Leaf Area Index and Root Depth parameters. [•] The coupled model was used to assess the impact of different land use scenarios. [•] Conversion between agriculture and forest was more significant than forest stand type. [•] Incorporating seasonal land use variations in hydrologic models is emphasized. [Copyright &y& Elsevier]

Sustainable urban transitions promise high mitigation and adaptation potential to address the effects of anthropogenic climate change. The two coastal megacities studied in this paper, Shanghai and Istanbul, have the potential for low-carbon urban transitions that can destabilize existing regimes. The destabilization is brought about by the disruptive business model innovations of the sharing economy in Shanghai's mobility sector and by the energy-efficient practices developed alongside the intensification of the building sector through the process of urban renewal in Istanbul. However, the emergence of such urban transitions through the actions of agents relies on the existence of enabling environments for regime destabilization. In a comparative case study of Shanghai and Istanbul, we assess the challenges of realizing regime destabilization opportunities through an enabling environment framework. We find that without adequate enabling environments for regime destabilization, urban transitions to sustainability may fail to achieve effective low-carbon action and make progress towards meeting the sustainable development goals. We also show that while deliberate and collective efforts are underway from multiple agents within and beyond the two megacities, the environments for regime destabilization in the building and transport sectors considered remain insufficient primarily due to conflicting priorities among key agents in the underlying urban systems. [ABSTRACT FROM AUTHOR]

Green-Win is the proposal where that government, society, and business can all reap benefits while at the same time playing a vital role in the transition to sustainable development and lower carbon futures. We argue that, while the Green-Win proposition is central to many state and expert models of sustainability transitions, as a construction, it belies more complex trade-offs and cognitive models of sustainability and societal transitions. Cultural models are cognitive representations shared by a community which provide both models of the world, which aid in interpreting what is in the world, how it works, what is possible (or not) and why, and models for the world, which suggest how to act in it to bring about desired outcomes (cf. Geertz 1973). We surveyed 225 respondents in Shanghai, China, Istanbul, Turkey, and Beirut, Lebanon to assess their basic beliefs about sustainability, specifically whether it is possible to implement concrete practices that realize environmental sustainability goals in conjunction with economic development—the Green-Win proposition. We found important similarities and differences among urban stakeholders' cultural models of sustainable development. For example, Chinese and Lebanese respondents displayed a strong belief that economic growth and environmental sustainability are compatible, while Turkish respondents showed significant disagreement with this proposition. We argue that such basic notions about the possibility of Green-Win opportunities between environmental sustainability and economic development are important to understand in the context of mitigating and adapting to climate change in critical urban environments. Cultural models of and for green development may either enable or inhibit transformations in urban systems according to local conditions. Finally, we discuss the potential implications of cultural models' research for targeting communications and engendering collaborations among diverse stakeholders in order to align perspectives and overcome barriers that may otherwise limit successful visioning, planning, and implementation for transformation towards sustainable development. [ABSTRACT FROM AUTHOR]

Processes aiming to achieve urban transformation that includes sustainability can result in green gentrification and thus promote exclusivist, private green spaces. At the same time, they compromise the ability of cities to promote more systemic sustainable development. Istanbul has long been a site of planned gentrification and displacement through urban renewal and regeneration projects, which have recently touted a sustainability angle. While sustainable urban renewal can have positive impacts on human health and well-being and is critical for addressing climate change and other environmental challenges, the benefits are rarely evenly distributed. Through an examination of sustainability-oriented urban renewal projects in Istanbul's Gaziosmanpaşa district, this study shows that vulnerable residents have been displaced by the planned gentrification and that such consequences are likely to be amplified by visions of green sustainability. It also illustrates that plans to harness the city's drive for economic growth and urban development risk making large parts of the "green" districts affordable only for relatively well-off citizens. Based on semi-structured interviews, non-participatory observation, and analysis of project and municipality-level documents, we find that even though seismic vulnerability and energy efficiency are cited as reasons for these transformations towards sustainability, policymakers are not paying sufficient attention to the political ecology of social exclusion and an increase in inequality that can result from sustainability-oriented urban renewal. [ABSTRACT FROM AUTHOR]

• Sodicity was investigated in a semiarid Calcisol of the Great Konya Basin. • pH gradually increased while the EC decreased with irrigation water treatment. • Water quality strongly influenced ion concentrations in calcareous soils. • Short-term leaching with poor-quality waters restricts permeability. • Poor quality irrigation treatments increase the risk of secondary salinization. The often-indispensable use of poor-quality irrigation water in drylands instigates diverse physicochemical dynamics leading to soil salinization and sodicity which are recognized as major contributors to land degradation. This study aimed to examine the effects of water quality and irrigation mode on solute transport conditions in terms of ion exchange of colloidal particles. Laboratory studies with undisturbed soil columns were carried out with two water treatments - tap and sodic waters - as well as two water flow velocities: fast leaching which corresponds to Darcy velocity equal to the saturated hydraulic conductivity and slow leaching equal to half the fast-leaching case. Results indicated that the flow velocities did not significantly influence pH, EC and ion concentrations due to the high calcium carbonate and clay contents of the soil which make the soil less permeable. However, flow velocity rapidly decreased in the fast leaching compared to that in slow leaching as the sodic water was applied. This reveals the destructive effect of Na+ in the soil. The EC rapidly dropped at the beginning of leaching for both water qualities opposite to pH, then became steady. All sodic applications caused an increase in Na+ till the end of treatments. This also resulted in variations in measured soluble anions. In general, sharp decreases in highly soluble anions were observed in all treatments, leading to an increase in HCO 3 –, especially for sodic treatments. Overall, sodicity caused significant changes in flow dynamics and ion concentrations and created favorable conditions for secondary salinization in this low permeable soil system. [ABSTRACT FROM AUTHOR]