Creating a quantitative, ecosystem-service-based index of nature in the highly urbanized and arid Los Angeles County

Before evaluating the abundance and quality of nature in a city, one must define the concept of nature according to resident experience and climatological conditions. For Los Angeles (L.A.) County, home to a sociologically diverse and highly developed city in a Mediterranean climate that experienced drought conditions for the last decade, this represents a formidable theoretical and empirical challenge. In support of an Integrated Vulnerability Assessment, we developed an index of natural resources with the aid of local partnerships. This effort required local expert participation and resulted in the creation of a large database of available regional data. This index was created to investigate the spatial footprint of natural resources in relation to predicted high risk natural hazard areas. This paper demonstrates analytical applications of this index, which consists of six component indicators: greenness, biodiversity, habitat fragmentation, significant ecological areas, tree canopy cover, and wetland cover. Data for each component were compiled into a geodatabase, scaled, aggregated to Census block group areas, and combined to create the natural resources index (the Index). The Index can then be compared with natural hazard spatial data to determine relative vulnerability to these hazards, interactions with other types of vulnerabilities, and where adaptive capacity may be lacking. Results highlight areas of opportunity for multifaceted risk mitigation and adaptation efforts.