Developing socio-ecological scenarios: A participatory process for engaging stakeholders.

Deltas are experiencing profound demographic, economic and land use changes and human-induced catchment and climate change. Bangladesh exemplifies these difficulties through multiple climate risks including subsidence/sea-level rise, temperature rise, and changing precipitation patterns, as well as changing management of the Ganges and Brahmaputra catchments. There is a growing population and economy driving numerous more local changes, while dense rural population and poverty remain significant. Identifying appropriate policy and planning responses is extremely difficult in these circumstances. This paper adopts a participatory scenario development process incorporating both socio-economic and biophysical elements across multiple scales and sectors as part of an integrated assessment of ecosystem services and livelihoods in coastal Bangladesh. Rather than simply downscale global perspectives, the analysis was driven by a large and diverse stakeholder group who met with the researchers over four years as the assessment was designed, implemented and applied. There were four main stages: (A) establish meta-framework for the analysis; (B) develop qualitative scenarios of key trends; (C) translate these scenarios into quantitative form for the integrated assessment model analysis; and (D) a review of the model results, which raises new stakeholder insights (e.g., preferred adaptation and policy responses) and questions. Step D can be repeated leading to an iterative learning loop cycle, and the process can potentially be ongoing. The strong and structured process of stakeholder engagement gave strong local ownership of the scenarios and the wider process. This process can be generalised for widespread application across socio-ecological systems following the same four-stage approach. It demands sustained engagement with stakeholders and hence needs to be linked to a long-term research process. However, it facilitates a more credible foundation for planning especially where there are multiple interacting factors.

A social-ecological analysis of drinking water risks in coastal Bangladesh.

Groundwater resources in deltaic regions are vulnerable to contamination by saline seawater, posing significant crisis for drinking water. Current policy and practice of building water supply infrastructure, without adequate hydrogeological analysis and institutional coordination are failing to provide basic drinking water services for millions of poor people in such difficult hydrogeological contexts. We apply a social-ecological systems approach to examine interdisciplinary data from hydrogeological mapping, a water infrastructure audit, 2103 household surveys, focus group discussions and interviews to evaluate the risks to drinking water security in one of 139 polders in coastal Bangladesh. We find that increasing access through public tubewells is common but insufficient to reduce drinking water risks. In response, there has been a four-fold growth in private investments in shallow tubewells with new technologies and entrepreneurial models to mitigate groundwater salinity. Despite these interventions, poor households in water-stressed environments face significant trade-offs in drinking water quality, accessibility and affordability. We argue that institutional coordination and hydrogeological monitoring at a systems level is necessary to mitigate socio-ecological risks for more equitable and efficient outcomes.

Risk assessment based on fuzzy synthetic evaluation method.

The IPCC fifth assessment report envisions risk of climate-related impacts as an outcome of the interaction of climate-related hazards with the vulnerability and the exposure of human and natural systems. This approach relies heavily on human perception, via expert opinions. As experts decide appropriate placement of an indicator in any of the exposure, sensitivity or adaptive capacity domains, several risk maps can potentially be created for the same study area. There is thus some degree of uncertainty in selecting the most appropriate and representative risk map from the several alternatives created by IPCC methods. On the other hand, Fuzzy Synthetic Evaluation (FSE) method, when used to assess risk, can handle this uncertainty much better, as there is no need to distribute indicators among different domains. In FSE, a specific indicator can either increase (positive sign) or decrease (negative sign) a risk, following a simple binary logic. This does not require any expert opinion and thus is free from subjective perception. In this study, risk maps are generated and compared by applying FSE method and two IPCC methods, as outlined in the third and fifth assessments (TAR and AR5). A variant of AR5 risk map is created by interchanging one indicator from the exposure domain to the sensitivity domain. It is found that risk zones are created with statistically significant difference when different IPCC methods are applied. This makes it uncertain to judge a specific risk map by a specific IPCC method as a true risk map. This uncertainty does not exist in FSE method as there is only one risk map where indicators are placed with certainty by following a simple binary logic for a known hazard domain. Hence, this risk map may be considered as the true risk map for the given set of indicators.