Data-Driven Wildland Fire Research

Trends in California Wildfire-related Legislature, 2001-2020
Rebecca Miller
PhD Candidate, Emmettt Interdisciplinary Program in Environment and Resources

The California State Legislature has responded to recent catastrophic wildfire seasons with a substantial increase in the number of wildfire-related bills proposed. Each legislative session lasts two years; in the 2001-2002 through 2015-2016 sessions, the legislature proposed an average of 24 wildfire bills per session. But during the 2017-2018 session (which included the Sonoma Complex, Thomas, Carr, Mendocino Complex Fires), the legislature proposed 59 wildfire bills. In addition, during the 2019-2020 session (Camp, Woolsey, Kincade, 2020 lightning complex fires), the legislature proposed 181 wildfire bills. Here, we explore recent trends in wildfire-related bills from the last ten full legislative sessions in California (2001-2002 through 2019-2020). First, we consider what factors may influence the likelihood of bill passage, focusing on (1) the bill's sponsorship (e.g. Republican v. Democrat, Assembly v. Senate, bipartisan or partisan sponsorship), (2) legislative procedures (e.g. committees reviewing the bill), (3) the bill’s stated focus in the disaster cycle (e.g. mitigation, preparedness, response), (4) the impacted population (e.g. a specific geographic scope or vulnerable population), and (5) the bill's use of repetitive or original language. Second, we use machine learning techniques to determine trends in bill topics over time. Specifically, we apply the Latent Dirichlet Allocation (LDA) model to conduct topic modeling. This approach allows the machine to automatically identify clusters of words in order to reveal otherwise hidden themes. Based on our topic modeling results, we present trends in legislative interest over time for topics like fuel treatments, homeowners' insurance, deenergization and public safety power shutoffs, and public health, among others. These findings are particularly critical as legislators respond to recent wildfire seasons with more wildfire-related bills. Understanding legislative priorities and what factors influence bill passage is crucial for crafting and implementing state policies that help reduce wildfire risk and improve wildfire resilience.