GIS-based tool development for flooding impact assessment on electrical sector

Abstract

Due to climate change, extreme weather events are increasing in frequency and intensity. Thus, critical infrastructures as power distribution must be secure and resilient to respond to and mitigate the impacts caused by extreme events. Accounting that the most valuable assets, human lives, are currently hosted in cities, these are considered as the most sensible and critical zones and are also constituted as the main focus of study. This statement is reflected in the increasing interest in making cities more resilient against extreme events, becoming a key research topic worldwide. Trying to tackle this goal, this paper focuses on the development of a GIS-based tool oriented to help decision-makers in planning while providing unitary and global views of the electric assets of a network considering their interrelations in a failure case. The study follows three main steps to achieve this purpose. First, the flood risk assessment while evaluating the flood depth hazard (taking into account the Average of Water Depth found in the flooded areas), the exposure of the assets (using Affected Area Rates), and their vulnerability (with the integration of Fragility curves), putting all the elements together into Failure Probabilities considering the interrelation between assets and the potential cascade effects. Second, calculating a cost assessment (from damage, business interruption, auxiliary cost, and non-supplied energy). Finally, calculating electrical network reliability indices, which provides highly valuable information about the status of the grid and the interruptions to customers when considering scenarios of extreme flooding events. Intending to prove the use and performance of the tool developed, this tool is applied to a real case study in Barcelona city. This case of study is constituted by two flooding scenarios (Current situation and Climate change with RCP 8.5) previously modeled and validated in other projects, and the Climate change scenario with measures applied to the water sector (increasing the drainage capacity of the city, and improving capacities of the sewer system). It is demonstrated how the improvements introduced by measures are interrelated and considerably improve the safety of the electrical network, mitigating consequences provoked by flooding extreme events by 60% in case of Average of Water Depth, 50% the failure probability, and 77% the costs provoked.