Changes in the exposure of California’s levee-protected critical infrastructure to flooding hazard in a warming climate

Abstract

Levee systems are an important part of California's water infrastructure, engineered to provide resilience against flooding and reduce flood losses. The growth in California is partly associated with costly infrastructure developments that led to population expansion in the levee protected areas. Therefore, potential changes in the flood hazard could have significant socioeconomic consequences over levee protected areas, especially in the face of a changing climate. In this study, we examine the possible impacts of a warming climate on flood hazard over levee protected land in California. We use gridded maximum daily runoff from global circulation models (GCMs) that represent a wide range of variability among the climate projections, and are recommended by the California's Fourth Climate Change Assessment Report, to investigate possible climate-induced changes. We also quantify the exposure of several critical infrastructure protected by the levee systems (e.g. roads, electric power transmission lines, natural gas pipelines, petroleum pipelines, and railroads) to flooding. Our results provide a detailed picture of change in flood risk for different levees and the potential societal consequences (e.g. exposure of people and critical infrastructure). Levee systems in the northern part of the Central Valley and coastal counties of Southern California are likely to observe the highest increase in flood hazard relative to the past. The most evident change is projected for the northern region of the Central Valley, including Butte, Glenn, Yuba, Sutter, Sacramento, and San Joaquin counties. In the leveed regions of these counties, based on the model simulations of the future, the historical 100-year runoff can potentially increase up to threefold under RCP8.5. We argue that levee operation and maintenance along with emergency preparation plans should take into account the changes in frequencies and intensities of flood hazard in a changing climate to ensure safety of levee systems and their protected infrastructure.

Simulation of transportation infrastructures resilience: a comprehensive review

“…General circulation models have been adopted to assess the impact of global warming and climate change on the determination of flood flow (Tofiq and Guven, 2014). For instance, Mallakpour et al (2020) used a general circulation model to simulate the variable direction of flood over the leveed area of California to quantify the relative changes of TI in future flood hazards.…”

Toward equitable grid resilience: operationalizing climate adaptation strategies to mitigate flooding impacts

“…This probability of flooding can increase due to climate change. Previous studies show that climate change worsens the intensity and frequency of extreme precipitation and floods in several regions (Ragno et al 2018, Chen et al 2019, Mallakpour et al 2020. For example, due to climate change, future extreme precipitation events, compared to historical events, may become 20% more intense and twice as frequent in highly populated areas across the United States.…”

“…Previous studies suggest that a warming climate worsens flood hazards in California (Hamlet et al 2007, AghaKouchak et al 2014, Osaka et al 2020, Wasko et al 2020. It is estimated that California's levee system will face substantial increases in flood hazards in the future, mainly due to climate change (Mallakpour et al 2020). The selected study area contains six levee systems (figure 2).…”

Flood impacts on urban road connectivity in southern China

“…Indirect damages are wide-ranging, including interruption of traffic that may lead to disruptions in enterprise production and financial losses 18 . In urban areas, indirect losses from floods may be more widespread, because high-rise buildings and other places of refuge could reduce people’s direct contact with floodwaters, while infrastructure in low-lying areas such as roads, water and gas pipelines, underground subway stations as well as parking lots are flooded, also causing substantial indirect losses 19 – 21 .…”