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In 2010 the U.S. Geological Survey (USGS), Coastal and Marine Geology Program completed three cruises to map the bathymetry of the main channel and shallow intertidal mudflats in the southernmost part of south San Francisco Bay. The three surveys were merged to generate comprehensive maps of Coyote Creek (from Calaveras Point east to the railroad bridge) and Alviso Slough (from the bay to the town of Alviso) to establish baseline bathymetry prior to the breaching of levees adjacent to Alviso and Guadalupe Sloughs as part of the South Bay Salt Pond Restoration Project (http://www.southbayrestoration.org). Since 2010 we have conducted four additional surveys to monitor bathymetric change in this region as restoration...
Coastal ecosystems have been identified by the International Panel on Climate Change (2007) as areasthat will be disproportionally affected by climate change. Recent sea-level rise projections range from 0.57to 1.1 m (Jevrejeva et al. 2012) or 0.75 to 1.9 m by Grinsted et al. (2010) and Vermeer and Rahmstorf(2009) by 2100, which are contingent upon the ambient temperature conditions and CO2 emissions. Sealevelrise projections for San Francisco Bay are 1.24 m by 2100 (Cayan et al. 2008). The expectedaccelerated rate of sea-level rise through the 21st century will put many coastal ecosystems at risk,especially those in topographically low-gradient areas.Sea-level rise response modeling was conducted at 12 tidal salt...
The aim of this USGS program is to provide site specific sea-level rise predictions to land managers through the intensive collection of field data and innovative predictive modeling. In 2009 and 2010, thousands of elevation and vegetation survey points were collected in salt marsh at 12 sites surrounding San Francisco Bay. The elevation data was synthesized into a continuous elevation model for each site, providing land owners valuable baseline data. This site hosts the project report, pages describing each of the 12 marshes visited in this study, and maps and GIS data for all of the marshes including high-resolution digital elevation models.
The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal–estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin–Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The...
We evaluated the biogeomorphic processes of a large (309 ha) tidal salt marsh and examined factors that influence its ability to keep pace with relative sea-level rise (SLR). Detailed elevation data from 1995 and 2008 were compared with digital elevation models (DEMs) to assess marsh surface elevation change during this time. Overall, 37 % (113 ha) of the marsh increased in elevation at a rate that exceeded SLR, whereas 63 % (196 ha) of the area did not keep pace with SLR. Of the total area, 55 % (169 ha) subsided during the study period, but subsidence varied spatially across the marsh surface. To determine which biogeomorphic and spatial factors contributed to measured elevation change, we collected soil cores...
Coastal areas are high-risk zones subject to the impacts of global climate change, with significant increases in the frequencies of extreme weather and storm events, and sea-level rise forecast by 2100. These physical processes are expected to alter estuaries, resulting in loss of intertidal wetlands and their component wildlife species. In particular, impacts to salt marshes and their wildlife will vary both temporally and spatially and may be irreversible and severe. Synergistic effects caused by combining stressors with anthropogenic land-use patterns could create areas of significant biodiversity loss and extinction, especially in urbanized estuaries that are already heavily degraded. In this paper, we discuss...
This set of elevation models was developed to understand current (2010) conditions of San Francisco salt marshes and for input into sea-level rise prediction models. These elevation models were built by interpolating surveyed elevation points. The elevation surveys were conducted with a Leica RX1230 Real-Time Kinematic GPS which is capable of < 2 cm vertical accuracy.
California Landscape Conservation Cooperative Project on estuarine shoals and vertebrate predators: In this report, we describe the integrated research program supported by the California LCC addressing sea level rise effects on estuarine shoals and the vertebrate predators dependent on these habitats. We present results from the first year objectives to determine the feasibility of the project and to: 1) host a modeling workshop with partners to identify what parameters are needed to model effects of sea level rise on the ecology of shoals and migratory birds; 2) use existing shoals modeling grids (Ganju and Schoellhamer 2010) to develop methodology for quantifying key metrics for habitat change; 3) conduct a comprehensive...
This project uses bottom-up modeling at a parcel scale to measure the effects of sea-level rise (SLR) on coastal ecosystems and tidal salt marshes. At selected tidal marshes, the project team will measure several parameters that will be incorporated into ArcGIS models creating comparable datasets across the Pacific coast tidal gradient with a focus on 2-4 sites in the California LCC (e.g. San Diego, San Francisco Bay Refuges). The ultimate goal is to provide science support tools for local adaptation planning from the bottom-up that may be implemented under a structured decision-making framework.Science Delivery Phase (2013): The objectives are to: (1) Disseminate site-specific baseline data and modeling results,...
Categories: Data, Project; Tags: 2011, 2013, Applications and Tools, CA, CA-Northern, All tags...
The USGS Coastal Ecosystem Response to Climate Change (CERCC) began in 2008 to deliver sea - level rise ecological response mod- els at a scale relevant for resource managers. Work was originally focused on the San Fran- cisco Bay estuary and then expanded to en- compass other Pacific coast sites. Our goal is to provide site specific measurements and results that land managers, planners, and those concerned with the conservation of near- shore habitats can use to make well - informed climate change adaptation strategies and deci- sions.
March 19, 2014 12:00-1:00 pm PSTSpeaker Glen MacDonald, Director of the UCLA Institute for the Environment and Sustainability.This webinar presents some basics on potential rates and magnitudes of relative sea level rise along the California coast over the 21st century as influenced by climate change, tectonics and other related factors. The potential accretion rates of selected marshes relative to anticipated sea level rise will be outlined and a multidisciplinary joint USGS-UCLA project to study past, present and future marsh response to sea level changes will be described.
This September, 2014 article in the Orange County Register highlights the project “Sea-level rise modeling across the California salt marsh gradient”.
In California, the near-shore area where the ocean meets the land is a highly productive yet sensitive region that supports a wealth of wildlife, including several native bird species. These saltmarshes, mudflats, and shallow bays are not only critical for wildlife, but they also provide economic and recreational benefits to local communities. Today, sea-level rise, more frequent and stronger storms, saltwater intrusion, and warming water temperatures are among the threats that are altering these important habitats.To support future planning and conservation of California’s near-shore habitats, researchers examined current weather patterns, elevations, tides, and sediments at these sites to see how they affect plants...
Salt marsh elevation and geomorphic stability depends on mineral sedimentation. Many Mediterranean-climate salt marshes along southern California, USA coast import sediment during El Niño storm events, but sediment fluxes and mechanisms during dry weather are potentially important for marsh stability. We calculated tidal creek sediment fluxes within a highly modified, sediment-starved, 1.5-km2 salt marsh (Seal Beach) and a less modified 1-km2 marsh (Mugu) with fluvial sediment supply. We measured salt marsh plain suspended sediment concentration and vertical accretion using single stage samplers and marker horizons. At Seal Beach, a 2014 storm yielded 39 and 28 g/s mean sediment fluxes and imported 12,000 and 8800...
In the Pacific Northwest, coastal wetlands support a wealth of ecosystem services including habitat provision for wildlife and fisheries and flood protection. The tidal marshes, mudflats, and shallow bays of coastal estuaries link marine, freshwater, and terrestrial habitats, and provide economic and recreational benefits to local communities. Climate change effects such as sea-level rise are altering these habitats, but we know little about how these areas will change over the next 50–100 years. Our study examined the effects of sea-level rise on nine tidal marshes in Washington and Oregon between 2012 and 2015, with the goal of providing scientific data to support future coastal planning and conservation. We compiled...
Climate change, when combined with more conventional stress from human exploitation, calls into question the capacity of both existing ecological communities and resource management institutions to experience disturbances while substantially retaining their same functions and identities. In other words, the physical and biological effects of climate change raise fundamental challenges to the resilience of natural ecosystems. Perhaps more importantly, the projected scope of ecological shifts from global climate change — and uncertainty about such changes — significantly stresses the capacity of legal institutions to manage ecosystem change. Existing governmental institutions lack the adaptive capacity to manage such...
The Deltares Delft3D FM (flexible mesh) model of the Bay-Delta that provides boundary conditions for the South San Francisco Bay geomorphic model, which is now a 1D model that is spatially extrapolated to 2D, was released at the Bay-Delta Conference in October 2014. The San Francisco Bay-Delta Community Model is an open source Delft3D FM model and allows for continuous development of a process-based, hydrodynamic surface water flow model of the San Francisco Bay-Delta system. The domain covers an area from Point Reyes up to the tidal limits near Sacramento and Vernalis and includes the entire Bay. A high-resolution mesh ultimately allows for detailed computations of flow (including salinity and temperature), sediment...
Workshops were held in each of the 3-6 areas to present study results and solicit visits with managers over 2-3 days. In addition, stakeholder involvement was recruited at 1-3 areas to develop a decision-making tool that incorporates climate change projections in management alternatives.
Decision makers that are responsible for stewardship of natural resources face many challenges, which are complicated by uncertainty about impacts from climate change, expanding human development, and intensifying land uses. A systematic process for evaluating the social and ecological risks, trade-offs, and cobenefits associated with future changes is critical to maximize resilience and conserve ecosystem services. This is particularly true in coastal areas where human populations and landscape conversion are increasing, and where intensifying storms and sea-level rise pose unprecedented threats to coastal ecosystems. We applied collaborative decision analysis with a diverse team of stakeholders who preserve, manage,...
The coastal region of California supports a wealth of ecosystem services including habitat provision for wildlife and fisheries. Tidal marshes, mudflats, and shallow bays within coastal estuaries link marine, freshwater and terrestrial habitats, and provide economic and recreational benefits to local communities. Climate change effects such as sea-level rise (SLR) are altering these habitats, but we know little about how these areas will change over the next 50–100 years. Our study examined the projected effects of three recent SLR scenarios produced for the West Coast of North America on tidal marshes in California. We compiled physical and biological data, including coastal topography, tidal inundation, plant...