Scotland's freshwater landscape and its resilience to change: an assessment to support future policy

Abstract

Future changes in climate, land use, and population are likely to lead to significant impacts on freshwater quality and quantity. To increase the resilience of freshwaters to the impact of future change, tools are required to investigate and communicate the complexity and uncertainty associated with future-focussed decision-making. To address this need, a robust collaborative decision-making framework was developed to inform the identification of resilient water management options. As a first stage in the collaborative framework, 27 stakeholders across Scotland were interviewed to understand their knowledge needs. The need for a greater understanding of the cumulative impacts of climatic and socio-economic change on freshwaters was an overarching ‘knowledge need’ identified.

To address the overarching ‘knowledge need’, a Bayesian Network (BN) model was developed as a tool for understanding the resilience of the freshwaters to the impacts of future change. Co-development of the tool was applied using the case study of the River Eden catchment, in eastern Scotland to address water quality issues - particularly reactive phosphorus concentrations from both diffuse and point sources - identified by stakeholders. Representatives from multiple sectors participated in a series of meetings, focus groups and workshops aimed at building the BN model and identifying management options for improving water conditions in the catchment both now and in the future. Plausible diverse future change scenarios to 2050 were developed to investigate their impacts on water quality issues in the catchment. Measuring the impacts of uncertain future change pathway scenarios on the catchment system informed the identification of five different management scenarios.

Management scenario testing, using the BN model, supported stakeholders in understanding that standard siloed approaches to water management would not increase catchment system resilience to the impacts of future change. Instead, collaborative and innovative action was required to improve freshwater conditions in the catchment, both now and in the future. The thesis addressed gaps in the need for improved methods for involving stakeholders in problem identification stages and methods for measuring and communicating the uncertainty associated with future-focused water management.

Policy, management and research recommendations are identified, addressing the need to review collaborative processes to improve future applications. The recommendations include the need for an implementation stage within the decision-making framework. Future BN applications should incorporate wider measures of success aligned with sector goals, such as detailed carbon accounting and financial considerations to support implementation. The development of a network of catchment partnerships to provide appropriate governance structures that ensure sectors are accountable for the implementation of management actions identified was recommended. Reflecting on the collaborative decision-making framework highlighted the need for higher resolution water quality monitoring and a central data hub to improve the representation of uncertainty in future modelling efforts.