Adaptation pathways to address climate change-induced flood risk in the Zemgale region, Latvia

Abstract

A comprehensive understanding of changing climate patterns and flood hazard dynamics is essential for effective climate change adaptation. One of the European Union's Horizon 2020 IMPETUS project demonstrator regions, Zemgale (Latvia), located in the Boreal biogeographic region of Northern Europe, is particularly vulnerable to flooding due to its flat agricultural landscapes, dense river network, and extensive floodplains. Under climate change, spring river flood regimes are being altered by earlier snow and ice melt, as well as by increasing heavy rainfall intensity, which heightens flash flood risks in urban areas. This study aimed to develop climate change adaptation pathways to improve regional preparedness for both river floods and heavy rainfall-induced flash floods through a co-design and co-creation process involving stakeholders from multiple governance levels, with the support of a risk reduction modeling team to establish alternatives for assessment. Adaptation options were identified and evaluated using multi-criteria analysis, considering, among others, effectiveness, costs, co-benefits, feasibility, and additional criteria. A set of structural and non-structural measures, including conventional approaches and innovative nature-based solutions, were selected to address rapid increases in river water levels and intense rainfall events. These measures were subsequently sequenced into adaptation pathways to respond to flood-related hazards and impacts, enhancing adaptive capacity and reducing vulnerability in both rural and urban areas of the Zemgale region under future climate conditions. To identify and evaluate alternative adaptation pathways, the Dynamic Contingency Response Tool (DCRT) was used. Modeling was conducted for three climate change and development scenarios (SSP1, SSP2, and SSP5), utilizing risk projections derived from the Risk Emerging and Problems Inference Engine (REPIE) tool. The outcomes of the risk analysis were discussed with stakeholders and considered in the development of the Zemgale Regional Climate Change Adaptation Plan.