The concept of complex social-ecological systems (SES) as a means for capturing system dynamics properties (e.g. interactions and feedbacks) has gained attention in policymaking and advancing evidence in understanding complex systems. In contexts with limited data, conceptual system dynamic models offer a promising entry point to overcome challenges in understanding SES dynamics, which is essential for managing the long-term sustainability of SES and human wellbeing. Here, we build on previous work focused on agricultural production and use participatory approaches to develop a conceptual System Dynamics (SD) model for the south-west coastal SES in Bangladesh encompassing multiple forms of livelihood (fisheries, shrimp farming and forests, as well as agriculture). Using qualitative methods, including focus group discussions with farmers, fishermen, shrimp farmers and forest people, as well as expert consultations, we identified interactions, feedback loops and thresholds for the SES. The conceptual system model developed independently by stakeholders is consistent with a model developed using an empirical approach and literature review. Feedback loops are identified for the ecological (e.g. climate and water, mangrove and salinity) and social (e.g. shrimp farming and mangrove, agricultural (e.g. crops) production and subsidy) sub-systems in the Bangladesh delta. The biophysical thresholds that impact social conditions include river water discharge (1500 to 2000 m³ s⁻¹), climate (28 °C) and soil salinity (~4 to ~10 dS m⁻¹). Exceeding these thresholds suggests that SES may lose resilience in the near future and increase the likelihood of regime shifts. Findings of this study contribute to the management of the deltaic ecosystem and provide specific policy recommendations for improving environmental sustainability and human well-being in the Bangladesh delta and can be further used as inputs into system dynamic modelling to simulate changes in this SES.

中文翻译：

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孟加拉国三角洲社会生态系统动力学概念化的参与式建模

复杂的社会生态系统（SES）的概念作为捕获系统动力学特性（例如，交互作用和反馈）的一种手段，已在决策过程中引起关注，并在理解复杂系统方面提供了先进的证据。在数据有限的情况下，概念性系统动力学模型为克服理解SES动力学方面的挑战提供了一个有希望的切入点，这对于管理SES和人类福祉的长期可持续性至关重要。在这里，我们以先前针对农业生产的工作为基础，并使用参与性方法为孟加拉国西南沿海SES开发了概念性的系统动力学（SD）模型，该模型涵盖了多种生计形式（渔业，对虾养殖和森林，以及农业）。使用定性方法，包括与农民，渔民进行的焦点小组讨论，对虾养殖者和森林人，以及专家咨询，我们确定了SES的相互作用，反馈回路和阈值。由利益相关者独立开发的概念系统模型与使用经验方法和文献综述开发的模型一致。确定了孟加拉国三角洲的生态（如气候和水，红树林和盐度）和社会（如虾类养殖和红树林，农业（如作物）生产和补贴）子系统的反馈回路。影响社会条件的生物物理阈值包括河水排放量（1500至2000 m 利益相关者独立开发的概念系统模型与使用经验方法和文献综述开发的模型一致。确定了孟加拉国三角洲的生态（如气候和水，红树林和盐度）和社会（如虾类养殖和红树林，农业（如作物）生产和补贴）子系统的反馈回路。影响社会条件的生物物理阈值包括河水排放量（1500至2000 m 由利益相关者独立开发的概念系统模型与使用经验方法和文献综述开发的模型相一致。确定了孟加拉国三角洲的生态（如气候和水，红树林和盐度）和社会（如虾类养殖和红树林，农业（如作物）生产和补贴）子系统的反馈回路。影响社会条件的生物物理阈值包括河水排放量（1500至2000 m³  s ^-1），气候（28°C）和土壤盐分（〜4至〜10 dS m ^-1）。超过这些阈值表明，SES可能会在不久的将来失去弹性，并增加政权转移的可能性。这项研究的发现有助于三角洲生态系统的管理，并为改善孟加拉国三角洲的环境可持续性和人类福祉提供了具体的政策建议，并可进一步用作系统动态建模的输入，以模拟该SES的变化。