Mapping California’s Resources

The coastal area of California is diverse, ranging from towering coastal bluffs to dense urban development and rolling pastoral lands. Immediately offshore, the underwater topography is equally varied with deep canyons, seamounts, and small shelves extending from the shoreline. The OPC is promoting efficient management of these land and marine environs by providing detailed surveys using modern technologies and sharing existing data.

Mapping and spatial data analyses are essential to ensuring the coastal area is understood and effectively utilized. California’s coastal region is home to numerous existing and proposed industrial activities, such as shipping, fishing, dredging, and energy development. Yet these areas also support varied recreational and conservation opportunities. Nearshore water quality is affected by runoff from coastal communities and agricultural practices; habitat and migratory patterns are disturbed by development and commercial activities; and sea level rise and climate change impacts will change the coast as we know it. With such a myriad of interests, uses, and potential impacts, the OPC is taking a leading role to record the coastal area and ensure important geospatial data are available to resource agencies.

The objective of the OPC is to modernize and consolidate geospatial information about this critical region and make it usable for coastal managers who need to assess cumulative impacts, competing interests, and permitting and planning decisions.

The OPC has three major initiatives under way to achieve this objective: the California Seafloor Mapping Project (CSMP), the terrestrial mapping program, and the Collaborative Geospatial Data Management Effort (CGDME).

• Initiated in 2008, the CSMP is collecting high-resolution bathymetry, or underwater maps, using state-of-the-art multibeam sonar technology. Simultaneously, sidescan sonar captures backscatter data, providing insight into the geologic makeup of the seafloor. Together these data will be used to create habitat and geologic base maps for all of California’s state waters (mean high water line out to three nautical miles).
• The terrestrial mapping program, currently under development, aims to produce high-resolution topography data from Oregon to Mexico, extending from the shoreline up to the 10 m topographic contour, using LiDAR (Light Detection and Ranging) technologies. In addition, high-resolution orthoimagery will provide photographic data in the same regions.
• The CGDME was started in 2009 to identify and promote sharing of datasets needed by the numerous state agencies with coastal and ocean interests, such as the Department of Fish and Game, the California Coastal Commission, the Bay Conservation and Development Commission, the State Lands Commission, and California State Parks. Datasets from federal agencies may also be incorporated into an interactive and accessible tool or framework designed to provide relevant data to resource managers, scientists, and the public for improved decision-making.

Integrating these three initiatives is a long-term goal. The topographic mapping data can be merged with the seafloor mapping data to produce a seamless onshore-offshore map that would greatly enhance the understanding and management of the coastal area. This modern high-resolution map can form the baseline map of any coastal geospatial decision-support tool. Following this integration, the OPC and California will be better prepared to:

• Better understand and mitigate the impacts from sea level rise
• Evaluate sites for renewable ocean energy and aquaculture projects
• Better understand sediment transport and sand delivery
• Ensure vessel safety
• Help identify tectonic faults and fault dynamics
• Forecast storm inundation and coastal erosion
• Better understand coastal earthquakes and tsunami potential
• More effectively regulate offshore coastal development
• Contribute to the federal process of Marine Spatial Planning
• Quantify cumulative impacts for different activities in the same location
• Identify key habitats that should be prioritize for protection

For example, the OPC funded a study to project inundation and erosion impacts from future sea level rise; however, the mapping data available for this project was less than optimal. In the future, such data will be readily available to anyone and will set the stage for a better understanding of our coastal and marine environment and how humans interact with this landscape.