Assessment of environmental impacts and risks related to climate change

Abstract

This PhD thesis examines state-of-the-art approaches applied with decision support systems (DSSs) to study climate change effects on coastal systems at the European and international levels. It applies a spatially resolved regional risk assessment (RRA) methodology to evaluate potential climate change related impacts on coastal groundwater aquifer and consequent risks for dependent ecosystems. Also it proposes and reflects on a new approach to successful relations in the science-policy interface aimed at climate change adaptation. Hence there are four specific undertakings: 1. The analysis of GIS-based decision support systems aimed at addressing climate change impacts on coastal waters and related ecosystems; 2. The refinement and adaptation of the regional risk assessment approach to coastal groundwater resources’ issues caused by climate change and anthropogenic pressures; 3. The application of a spatially resolved RRA methodology with the GIS-based DEcision support SYstem for COastal climate change impacts assessment (DESYCO tool), to identify climate change related threats on coastal aquifer and dependent ecosystems, and to particularly rank areas at risk in the lower Esino River valley in the Marche region in Italy; 4. The application of communities of practice theory to examine two model cases, to highlight areas of potential opportunities of and in disagreements with the theory, and to understand how a successful science-policy interface in the climate change adaptation arena could be envisioned as a community of practice. Firstly, the thesis selects twenty DSSs via a survey of literature and examines such according to the defined specific criteria, to describe and evaluate their actual applicability. The analysis highlighted the relevance of developing climate change impact assessment and management at the regional scale (i.e. subnational and local), according to the requirements of policy and regulatory frameworks, and to the methodological and technical features of the considered DSSs. Most of the examined DSSs show a regional to local applicability with a moderate to high flexibility, and prove to support the evaluation of climate change impacts via relevant functionalities. However, these DSSs were applied to analyse particular climate change impact on coastal sectors (15 out of the 20 DSS), regardless of the complexity and interrelatedness of coastal systems’ impacts. Secondly, the thesis considers the conceptual regional risk assessment and groundwater impacts integrated frameworks, to implement relevant outputs from climate, hydrological and hydrogeological models that were applied to the lower Esino River basin, at the global and sub-continental scales. The models’ outputs (i.e. projections in climate variables) were used to develop potential hazards metrics that were specifically defined according to different precipitation projections with reference to seasons. These metrics were used to analyse consequent effects of changes in groundwater quantity and quality at the basin scale using the spatially resolved methodology. This methodology employed several assessment steps (i.e. hazard, exposure, susceptibility, risk and damage), which were implemented with the GIS-based DESYCO tool, to characterize relative risks from changes in groundwater quantity and quality on coastal groundwater-dependent ecosystems (e.g. wells, river, agricultural areas, lakes, and forests and semi-natural environments), in the lower Esino River valley, considering the defined hazard metrics and indicators/indices used to construct potential climate change scenarios and analyse relevant impacts. Groundwater Level Variations (GLV) and Saltwater Intrusion (SI) impacts were evaluated by the regional scale analysis of climate change impacts on coastal groundwater aquifer and dependent ecosystems. This employed the aggregation of the lower Esino River valley’s vulnerability assessment (i.e. physical, social, economic and environmental factors) with the defined climate change scenarios, constructed according to precipitation projections with reference to seasons for the 2070-2100 timeframe, based on IPCC A1B emission scenarios. Significant results from the analysis highlight that potential climate changes will exert slight difference in impacts on the lower Esino River valley. In summer, there will be limited direct effects from GLV on specific agricultural areas and natural systems located along the coastline and surface water bodies. That is to say, less than 5% of the total exposed surface of agricultural areas and 50% of natural systems will be at high risk. Superficial water bodies will experience more direct consequences through decline in groundwater depth in the summer. About 40% of total exposed surface of the Esino River and 20% of the lakes will be at very high risk of GLV impacts. Moreover, saltwater intrusion impacts will be restricted to the coastal strip, and thus will exert very limited effects on the Esino coastal aquifer in the future seasons and fewer indirect consequences for dependent ecosystems. Thirdly, the thesis applies the communities of practice theory in a new way, by examining two climate change adaptation projects (e.g. SALT in Italy and Red River Delta in Vietnam) as model cases. The purpose is to highlight areas of potential opportunities of and in disagreements with the theory, and to understand how a successful science-policy interface in these projects could be envisioned as a community of practice. The assumption is that the social contexts in which these projects exist could be established by the concepts of ‘communities of practice,’ which defines activities as social processes and historical practices that engage researchers and experts on the one hand, and experts, managers and local stakeholders on the other. The cases were compiled from open-ended surveys, interactive research experience and observation, and were inductively reflected on vis-à-vis communities of practice. The model cases revealed challenges as well as potential opportunities for communities of practice. They exist within a middle space (social context) that could facilitate personal and professional relationships, promote formal and informal interactions, needed to negotiate different expertise and narrow apparent boundaries. The thesis concludes that vigorous and dynamic communities of practice promise to nurture the social context in which participants in adaptation projects are potentially engaged, and thus provide a provisional support to the science-policy interface.