Fire to Water

Over the past century, wildfire risk in California has surged due to a combination of urbanization, anthropogenic influence, and climate. In turn, ecosystems, including aquatic habitats, have been drastically impacted. While several studies have documented the impact of wildfires on streams and freshwater runoff in California, wildfires are understudied as major sources of land-based nutrient and other contamination to the ocean. Further, there is little research on oceanic impact and response to major fire-related inputs. USC Sea Grant has funded a study that will use satellite-derived remote sensing data to assess the impacts of wildfires on regional coastal water quality at high temporal and spatial scales. The project aims to monitor stormwater runoff and coastal waters in fire-impacted and reference areas, conduct analyses to reveal interactions between satellite imagery and the drivers of spatial water quality trends observed (in situ measurements), and perform course-based research on satellite detection of post-fire coastal water quality in local surface waters.

This research will provide key insights into the short and long-term impacts of coastal and inland wildfires on coastal water quality by quantifying the resulting turbidity plume extent with respect to precipitation events following the wildfires. This project is especially timely given the need to understand the complex interactions among water quality parameters that have led to the worst Harmful Algal Blooms in recent history in Southern California. The workflow in this research can be applied to other coastal areas vulnerable to wildfires, and will be especially pivotal to communities with less resources for in situ monitoring. Additionally, results from this research can help advise future efforts and regulations around responses to water quality changes resulting from post-fire precipitation – for example, this work could help determine a reasonable time frame for avoiding ocean exposure to microbial contaminants after a rain event.