Compounding effects of climate change and WUI expansion quadruple the likelihood of extreme-impact wildfires in California

Nature Portfolio (Springer Nature) | February 21st, 2025

Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the

Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the “Integrated Human-centric Wildfire Risk Index (IHWRI)” to quantify the compounding effects of fire-weather intensification and anthropogenic factors—including ignitions and human settlement into wildland—on wildfire risk. While climatic trends increased the frequency of high-risk fire-weather by 2.5-fold, the combination of this trend with wildland-urban interface expansion led to a 4.1-fold increase in the frequency of conditions conducive to extreme-impact wildfires from 1990 to 2022 across California. More than three-quarters of extreme-impact wildfires—defined as the top 20 largest, most destructive, or deadliest events on record—originated within 1 km from the wildland-urban interface. The deadliest and most destructive wildfires—90% of which were human-caused—primarily occurred in the fall, while the largest wildfires—56% of which were human-caused—mostly took place in the summer. By integrating human activity and climate change impacts, we provide a holistic understanding of human-centric wildfire risk, crucial for policy development.

Defining urban resilience: A review

Landscape and Urban Planing (Elsevier) | March 1st, 2016

Fostering resilience in the face of environmental, socioeconomic, and political uncertainty and risk has captured the attention of academics and decision makers across di

Fostering resilience in the face of environmental, socioeconomic, and political uncertainty and risk has captured the attention of academics and decision makers across disciplines, sectors, and scales. Resilience has become an important goal for cities, particularly in the face of climate change. Urban areas house the majority of the world's population, and, in addition to functioning as nodes of resource consumption and as sites for innovation, have become laboratories for resilience, both in theory and in practice. This paper reviews the scholarly literature on urban resilience and concludes that the term has not been well defined. Existing definitions are inconsistent and underdeveloped with respect to incorporation of crucial concepts found in both resilience theory and urban theory. Based on this literature review, and aided by bibliometric analysis, the paper identifies six conceptual tensions fundamental to urban resilience: (1) definition of ‘urban’; (2) understanding of system equilibrium; (3) positive vs. neutral (or negative) conceptualizations of resilience; (4) mechanisms for system change; (5) adaptation versus general adaptability; and (6) timescale of action. To advance this burgeoning field, more conceptual clarity is needed. This paper, therefore, proposes a new definition of urban resilience. This definition takes explicit positions on these tensions, but remains inclusive and flexible enough to enable uptake by, and collaboration among, varying disciplines. The paper concludes with a discussion of how the definition might serve as a boundary object, with the acknowledgement that applying resilience in different contexts requires answering: Resilience for whom and to what? When? Where? And why?

Drought impact on cropland use monitored with AVIRIS imagery in Central Valley, California

Science of the Total Environment (Elsevier) | November 19th, 2022

During 2012–2016 California experienced the longest and most severe drought in the last centuries. This water scarcity led to an increase in non-cultivated croplands du

During 2012–2016 California experienced the longest and most severe drought in the last centuries. This water scarcity led to an increase in non-cultivated croplands during this period. The objective of this study was to quantify agricultural trends in the Central Valley (California) at peak growth from 2013 to 2016 during the drought and in 2017–2018 post-drought. For this purpose, we analysed yearly official harvested area reported at county level for the main crops and compared them to visible-shortwave infrared (VSWIR) spectra acquired by the Airborne Visible/Infrared Imaging-Spectrometer (AVIRIS-classic) over 2334 km2 of the Central Valley each year. Multiple Endmember Spectral Mixture Analysis (MESMA) was applied to AVIRIS data to estimate green vegetation (GV), non-photosynthetic vegetation (NPV) and soil fractions in crop fields each year. MESMA and crop reports (R2 = 0.9) showed that soil (i.e.; non-cultivated areas) increased during the summers of the drought; with the smallest GV area in 2015, the second year classified with exceptional drought in this period. According to MESMA, 34 % of the cropland was covered by GV in 2015, and 69.5·104 ha according to the crop reports. MESMA also registered the highest value of soil area in 2015 (48 %). The year with most cultivated area was 2017, the wettest year in the studied period, with 54 % of the croplands covered by GV and 75.2·104 ha. This study verified that the non-cultivated areas increased in the Central Valley during the exceptional drought period and validated the use of AVIRIS imagery to monitor broad-scale cropland use changes in future climatic extreme events.

Effects of Urban Development on Stream Ecosystems in Nine Metropolitan Study Areas Across the United States

U.S. Geological Survey (USGS) | November 13th, 2012

Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a ha

Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a half of almost continuous development. Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the day-to-day realities of most Americans. Nowhere are the environmental changes associated with urban development more evident than in urban streams. Contaminants, habitat destruction, and increasing streamflow flashiness resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic species. Every stream is connected downstream to larger water bodies, including rivers, reservoirs, and ultimately coastal waters. Inputs of chemical contaminants or sediments at any point along the stream can cause degradation downstream with adverse effects on biological communities and on economically valuable resources, such as fisheries and tourism. In response to general concerns about the degradation of urban streams, the U.S. Geological Survey (USGS) conducted a national-scale, scientific investigation of the effects of urban development on stream ecosystems. Nine metropolitan study areas of the United States were selected—Portland, Oregon; Salt Lake City, Utah; Birmingham, Alabama; Atlanta, Georgia; Raleigh, North Carolina; Boston, Massachusetts; Denver, Colorado; Dallas, Texas; and Milwaukee, Wisconsin. The studies were conducted in Salt Lake City, Birmingham, and Boston in 1999–2000; in Atlanta, Raleigh, and Denver in 2002–2003; and in Portland, Dallas, and Milwaukee in 2003–2004. The comprehensive investigation of all nine studies focused on three broad questions of interest to decision makers: 1. What are the primary effects of urban development on stream ecosystems? 2. How do the effects of urban development on stream ecosystems vary regionally across the country? 3. Which urban-related stressors are most closely linked to biological community degradation, and how can multiple stressors be managed to protect stream health as a watershed becomes increasingly urbanized? RELATED DOCUMENT: Strategies for Managing the Effects of Urban Development on Streams

Equity in Stormwater Investments: Measuring Community Engagement and Disadvantaged Community Benefits for Equitable Impact in the Safe Clean Water Program

Publisher not available | August 4th, 2022

The Safe, Clean Water Program (SCWP) reflects the will of the voters of Los Angeles County, who approved Measure W in 2018 by close to 70%. The ballot measure established

The Safe, Clean Water Program (SCWP) reflects the will of the voters of Los Angeles County, who approved Measure W in 2018 by close to 70%. The ballot measure established a perpetual parcel tax “to fund projects and programs to increase stormwater capture and reduce stormwater and urban runoff pollution” in Los Angeles County “to increase water supply, improve water quality, and, where appropriate, provide community enhancements such as the greening of schools, parks, and wetlands, and increased public access to rivers, lakes, and streams.” In an ordinance implementing the Safe Clean Water Program, the county Board of Supervisors included provisions to prioritize equity in implementation and affirmed an intention to address inequity in infrastructure in August 2021. Those provisions gave rise to this report, which provides advice drawn from research and stakeholder engagement to the Los Angeles County Flood Control District (LACFCD) for measuring community engagement and Disadvantaged Community Benefits to better achieve the equitable impact sought by the SCWP. As part of a broader SCWP Metrics and Monitoring Study (MMS) commissioned by the LACFCD, we were charged with conducting research, consulting with stakeholders, and giving advice to the SCWP for metrics to measure community engagement and Disadvantaged Community Benefits.

Estuary News, April 2000

San Francisco Estuary Partnership (SFEP) | April 15th, 2000

Estuary News, April 2010

San Francisco Estuary Partnership (SFEP) | April 15th, 2010

Estuary News, August 1994

San Francisco Estuary Partnership (SFEP) | August 15th, 1994

Estuary News, August 1996

San Francisco Estuary Partnership (SFEP) | August 15th, 1996

Estuary News, August 1997

San Francisco Estuary Partnership (SFEP) | August 15th, 1997