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Research about California

Source-linked reports with geographic coverage including California.

At least 433 records · Page 24Linked to original sources
USGS2024

Modeling coupled dynamics of an empirical predator-prey system to predict top predator recovery

Limited data, time, and funding lead conservation managers to make difficult choices in managing species recovery. Coupled dynamical models are relied upon for decision support, but their application to empirical predator-prey systems has generally been restricted to small, tractable species. To broaden their use in conservation decision-making, we developed a model suitable for predicting the population dynamics of a larger apex carnivore and its prey. We selected southern sea otters ( Enhydra lutris nereis ) and their primary estuarine prey as our case study and parameterized the dynamical model with data on sea otter, clam, and crab abundances; predator-prey interactions; and sea otter bioenergetics collected from Elkhorn Slough, CA. Our model, having integrated all these salient factors, was able to successfully reproduce trends in taxa abundance as well as shifts in sea otter diet composition and energy intake rates. Rich data inputs allow the model to predict population dynamics over realistic temporal scales not only for the site of data collection, but also for similar estuaries uncolonized by sea otters. Based on model projections parameterized with prey survey data from two such estuaries, Tomales Bay and Drakes Estero, we predict the sites could support over 160 sea otters and may hold potential to further species recovery. In systems with good data availability, the model has high predictive power and can provide multi-taxa projections useful for making informed management decisions.

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USGS2024

Prototyping structured decision making for water resource management in the San Francisco Bay-Delta

A structured decision making (SDM) approach can help evaluate tradeoffs between conservation and human-benefit objectives by fostering communication and knowledge transfer among stakeholders, decision makers, and the public. However, the process is iterative and completing the full process may take years. It can be difficult to initiate an SDM effort when problems seem insurmountable. Occasionally, SDM may not even be the best or correct approach for addressing the conservation problem at hand. We describe the implementation of an SDM process to help inform difficult decisions related to competing objectives. We convened a diverse stakeholder group from the largest estuary in the western United States; the San Francisco Bay and Sacramento-San Joaquin Delta (Bay-Delta). The stakeholder group consisted of representatives from local, state, and federal agencies, non-profit organizations, and recreational fishers. The stakeholder group agreed on a problem statement and identified four priority objectives related to Chinook salmon, delta smelt, water availability and reliability, and agricultural water use. Furthermore, they proposed 14 candidate management actions to achieve their objectives. The group then used existing quantitative models and data to evaluate trade-offs in proposed management actions to identify areas of agreement of proposed candidate actions. The clear communication of the problem statement and objectives among the stakeholder group, along with evaluation of tradeoffs and uncertainty via decision-support models suggest that a full SDM approach may work in the Bay-Delta. We further communicate lessons learned during our implementation of SDM to help guide future SDM efforts in the region and elsewhere.

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USGS2024

An open-source workflow for scaling burn severity metrics from drone to satellite to support post-fire watershed management

Wildfires are increasing in size and severity across much of the western United States, exposing vulnerable wildland-urban interfaces to post-fire hazards. The Mediterranean chaparral region of Northern California contains many high sloping watersheds prone to hazardous post-fire flood events and identifying watersheds at high risk of soil loss and debris flows is a priority for post-fire response and management. Uncrewed Aerial Systems (UAS; aka drones) offer post-fire management teams the ability to quickly mobilize and survey burned areas with very high-resolution imagery (∼1 cm), facilitating emergency management and post-fire hazard assessment. However, adoption of this technology by hazard response teams may be hindered by complicated workflows for UAS data acquisition, image processing and analysis. We present an open-source workflow using mature Geographic Information Systems (GIS) software and Python packages in a Jupyter Notebook environment that guides users through classification of true-color UAS imagery to generate high resolution burn severity maps which can then be scaled across larger watersheds using Sentinel-2 normalized burn ratio (NBR) images. Soil burn severity classifications using a weighted brightness (WB) image and Char Index (CI) generated from UAS imagery were validated with in-situ data and random stratified points, resulting in the CI having the highest overall accuracy of 87.5%. CI also displayed a marginally stronger relationship over the WB with the post-fire Sentinel-2 NBR, R 2 = 0.79 and R 2 = 0.78 respectively. Our methods offer the unique opportunity to standardize GIS workflows, promoting replication through transparency, while improving the user's understanding of scientific GIS functionality.

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USGS2024

Seismicity zoning at Coso geothermal field and stress changes from fluid production and migration

The Coso geothermal field is a major geothermal power production site in the western United States. It has been observed that low-magnitude seismic events ( M < 3.71) are unevenly distributed in three distinct zones, namely, nearfield (<3 km), midfield (3–6 km), and farfield (> 6 km) from the Coso geothermal plant. These zones exhibit distinct changes in earthquake location before and during geothermal production episodes that began in 1986. After 1986, the midfield region of the main flank experiences a significantly lower seismicity rate than the surrounding areas before production episodes. During 2014–2019, the farfield earthquakes cluster in the eastern and western parts of the greater Coso area, which is discernably different from how those pre-production earthquake events were distributed along the conjugate NW-SE and SW-NW trending structures across the main flank. Here, we analyze the stage of stress with finite-element-based poroelastic simulations to illustrate how the spatiotemporal evolution of the seismicity is associated with the pattern of stress perturbations caused by fluid migration amid the operations of geothermal power plants. Generally, ∼70% of co-production seismicity is found in zones of increased Coulomb stress between 2014 and 2019 at >99% confidence. Meanwhile, the midfield zone of seismic paucity overlaps with the zone of decreasing pore-fluid pressure. Overall, the results provide a physical explanation of how decadal geothermal operations at Coso have perturbed stress-field changes and contributed to the evolving characteristic seismic pattern, shedding insights into assessing the seismic hazard in other geothermal settings.

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USGS2024

The invasive acanthocephalan parasite Pachysentis canicola is associated with a declining endemic island fox population on San Miguel Island

In the late 1990s, the San Miguel Island fox ( Urocyon littoralis littoralis ) faced near-extinction. Fourteen of the 15 remaining foxes were placed into an island-based captive breeding program used to repopulate the island. Although the fox population in San Miguel reached pre-decline numbers by 2010, a second decline started around 2014, coincidental with a newly observed acanthocephalan parasite. To identify this introduced acanthocephalan species and determine the pathologic consequences of its infection on the health of foxes, we used an extensive record of island fox necropsies and associated parasite collections. In addition, we used detailed fox capture-recapture data to investigate population health and demographic trends of foxes before and after parasite emergence. We identify the parasite as Pachysentis canicola, a common acanthocephalan in mainland foxes in North America. The parasite was detected in 69% of the necropsied foxes from San Miguel Island and was not found in any of the other five Channel Island fox subspecies. Health impacts attributed to the acanthocephalan parasite, including erosive and ulcerative enteritis, transmural necrosis, and inflammation, were described in 47% of the foxes infected with the acanthocephalan. Despite infection with various other helminth parasite species, body condition remained good and the mortality rate low in San Miguel Island foxes until the arrival of the acanthocephalan. Body condition improved after 2018, perhaps due to increases in rainfall following a drought, but remained 27% lower than the pre-acanthocephalan period, which suggests that environmental conditions and parasitism jointly drive fox population dynamics.

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USGS2024

Morbidity in California giant salamander (Dicamptodon ensatus Eschscholtz, 1833) caused by Euryhelmis sp. Poche, 1926 (Trematoda: Heterophyiidae)

In the fall of 2021, California Department of Fish and Wildlife reported larval and adult California giant salamanders ( Dicamptodon ensatus Eschscholtz, 1833) with skin lesions at multiple creeks in Santa Clara and Santa Cruz Counties, California, USA. Field signs in both stages included rough, lumpy textured skin, and larvae with tails that were disproportionately long, flat, wavy, and flaccid. Presence of large-bodied larvae suggested delayed metamorphosis, with some larvae having cloudy eyes and suspected blindness. To determine the cause of the disease, three first-of-the-year salamanders from one location were collected, euthanized with 20% benzocaine, and submitted for necropsy to the U.S. Geological Survey, National Wildlife Health Center. Upon gross examination, all salamanders were emaciated with no internal fat stores, and had multiple pinpoint to 1.5-mm diameter raised nodules in the skin over the body, including the head, gills, dorsum, ventrum, all four limbs, and the tail; one also had nodules in the oral cavity and tongue. Histologically all salamanders had multiple encysted metacercariae in the dermis, subcutis, and skeletal muscles of the head, body, and tail that were often associated with granulomatous and granulocytic inflammation and edema. A small number of encysted meta cercariae or empty cysts were present in the gills with minimal inflammation, and rarely in the kidney with no associated inflammation. Morphology of live metacercariae (Trematoda: Heterophyiidae), and sequencing of the 28S rRNA gene identified a species of Euryhelmis (Poche, 1926). Artificial digestion of a 1.65 g, decapitated, eviscerated carcass yielded 773 metacercariae, all of similar size and morphology as the live specimens. Based on these findings, the poor body condition of these salamanders was concluded to be due to heavy parasite burden. Environmental factors such as drought, increased temperature, and overcrowded conditions may be exacerbating parasite infections in these populations of salamander.

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USGS2024

Mixed responses of tenebrionid beetles to solar energy development in the Mojave Desert

Solar energy development causes land-use change and habitat alteration that may affect desert ecosystems. Tenebrionid beetles have evolved to exploit desert environments and heavily contribute to ecosystem functionality in aridlands, yet their species-specific, ecological responses to solar energy development are unknown. Our objective was to elucidate effects of solar energy development decisions at a solar power facility (392 MW) on a tenebrionid beetle community in the Mojave Desert. Seven years post-construction, we used pitfall traps to collect tenebrionid beetles for one month in treatments representing variably intense site preparation practices and conservation measures, including blading (i.e., bulldozing), mowing, and establishment of undeveloped patches in solar fields, replicated across three power blocks comprising the facility and in undeveloped control sites surrounding the facility. Blading caused significant, deleterious effects on tenebrionid beetle abundance, species richness, and diversity. Ordination revealed apparent overlap of non-bladed treatments and controls, suggesting that intermediate levels of disturbance from less intensive solar energy development decisions may serve to minimize negative effects of solar energy development on tenebrionid communities. Anepsius delicatulus and Triorophus laevis , the two most commonly collected tenebrionids, were significantly more abundant in non-bladed treatments in the solar facility than in undeveloped controls; thus, solar facilities with minimized disturbance to vegetation may provide preferred habitat for certain tenebrionid species. Our results demonstrate the value of understanding variable responses of insects to solar energy development decisions in deserts to inform real-world adaptive management of natural resources during the renewable energy transition.

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USGS2024

Will there be water? Climate change, housing needs, and future water demand in California

Climate change in California is expected to alter future water availability, impacting water supplies needed to support future housing growth and agriculture demand. In groundwater-dependent regions like California's Central Coast, new land-use related water demand and decreasing recharge is already stressing depleted groundwater basins. We developed a spatially explicit state-and-transition simulation model that integrates climate, land-use change, water demand, and groundwater gain-loss to examine the impact of future climate and land use change on groundwater balance and water demand in five counties along the Central Coast from 2010 to 2060. The model incorporated downscaled groundwater recharge projections based on a Warm/Wet and a Hot/Dry climate future from a spatially explicit hydrological process-based model. Two urbanization projections from a parcel-based, regional urban growth model representing 1) recent historical and 2) state-mandated housing growth projections were used as alternative spatial targets for future urban growth. Agricultural projections were based on recent historical trends from remote sensing data. Annual projected changes in groundwater balance were calculated as the difference between land-use related water demand, based on historical estimates, and climate-driven recharge plus agriculture return flows. Results indicate that future changes in climate-driven groundwater recharge, coupled with cumulative increases in agricultural water demand, result in overall declines in future groundwater balance, with a Hot/Dry future resulting in cumulative groundwater decline in all but Santa Cruz County. Cumulative declines by 2060 are especially prominent in San Luis Obispo (−2.9 to −5.1 Bm 3 ) and Monterey counties (−6.5 to −8.7 Bm 3 ), despite limited changes in agricultural water demand over the model period. These two counties show declining groundwater reserves in a Warm/Wet future as well, while San Benito and Santa Barbara County barely reach equilibrium. These results suggest future groundwater supplies may not be able to keep pace with regional demand and declining climate-driven recharge, resulting in a potential reduction in water security in the region. However, our county-scale projections showed new housing and associated water demand does not conflict with California's groundwater sustainability goals. Rather, future climate coupled with increasing agricultural groundwater demand may reduce water security in some counties, potentially limiting available groundwater supplies for new housing.

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USGS2024

Microtextural evidence for the recrystallization of opal-A to quartz in epithermal veins: A case study from the McLaughlin deposit, California

High-grade ores in low-sulfidation epithermal deposits commonly consist of banded veins containing quartz as the most abundant gangue mineral. Previous studies suggested that at least some of the quartz has formed as a product of recrystallization from a noncrystalline silica precursor. Detailed petrographic studies confirm that high-grade veins from the <2.2 Ma McLaughlin deposit in California were originally entirely composed of opal-A G . The noncrystalline silica is isotropic in crossed-polarized light and consists of compacted microspheres that are up to several micrometers in size. In many bands of the high-grade veins, the thermodynamically unstable opal-A G has matured to quartz. The recrystallization of the noncrystalline silica resulted in the development of quartz and ore textures that mask the original conditions of vein formation. Incipient recrystallization of the opal-A G caused the formation of lepispheres consisting of opal-CT as well as the development of concentrically banded silica spheres. Continued maturation led to the growth of elongated quartz crystals or complexly shaped quartz aggregates in the cores of the concentrically banded silica spheres. Amalgamation of quartz crystals caused the development of mosaic quartz or flamboyant quartz. Ripening produced large prismatic quartz crystals, which are characterized by zones of feathery appearance. Fluid inclusions within the quartz formed through recrystallization are typically highly irregular in shape and show inconsistent liquid-to-vapor volumetric proportions, but assemblages with consistent ratios are also present. Bands rich in fluid inclusions occurring along former recrystallization fronts in prismatic quartz crystals resemble growth zones in zonal quartz. Recrystallization of the silica matrix resulted in grain coarsening of the ore minerals and encapsulation of ore minerals by quartz. In areas where recrystallization of the noncrystalline silica proceeded to completeness, the quartz textures could be easily misinterpreted to indicate that quartz growth occurred in open space with the ore minerals infilling vug spaces. Correct recognition of recrystallization textures has significant implications for paragenetic investigations on vein material from epithermal deposits as well as the design of fluid inclusion studies.

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USGS2024

Per- and polyfluoroalkyl substances (PFAS) in drinking water in Southeast Los Angeles: Industrial legacy and environmental justice

Per - and polyfluoroalkyl substances (PFAS) are persistent chemicals of increasing concern to human health. PFAS contamination in water systems has been linked to a variety of sources including hydrocarbon fire suppression activities, industrial and military land uses, agricultural applications of biosolids, and consumer products. To assess PFAS in California tap water, we collected 60 water samples from inside homes in four different geographic regions, both urban and rural. We selected mostly small water systems with known history of industrial chemical or pesticide contamination and that served socioeconomically disadvantaged communities. Thirty percent of the tap water samples (18) had a detection of at least one of the 32 targeted PFAS and most detections (89 %) occurred in heavily industrialized Southeast Los Angeles (SELA). The residents of SELA are predominately Latino and low-income. Concentrations of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) ranged from 6.8 to 13.6 ng/L and 9.4–17.8 ng/L, respectively in SELA and were higher than State (PFOA: 0.007 ng/L; PFOS: 1.0 ng/L) and national health-based goals (zero). To look for geographic patterns, we mapped potential sources of PFAS contamination, such as chrome plating facilities, airports, landfills, and refineries, located near the SELA water systems; consistent with the multiple potential sources in the area, no clear spatial associations were observed. The results indicate the importance of systematic testing of PFAS in tap water, continued development of PFAS regulatory standards and advisories for a greater number of compounds, improved drinking-water treatments to mitigate potential health threats to communities, especially in socioeconomically disadvantaged and industrialized areas.

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USGS2024

Application of non-stationary shear-wave velocity randomization approach to predict 1D seismic site response and its variability at two downhole array recordings

Accounting for uncertainties in seismic site response is crucial to improving the performance of one-dimensional (1D) ground response analyses (GRAs) at downhole array recording sites. In addition to site effects, uncertainties in 1D-GRAs can also be contributed from the seismic source and/or path. Though often representing not more than one percent of the distance (path) from the source, site conditions are known to have an enormous influence on ground shaking. In this study, we focus on the site shear-wave velocity ( V S ) structure, which is the main ingredient for estimating the variability of site response. As such, V S can manifest aleatory uncertainties related to the effects of small-scale spatial heterogeneities within the near surface, thus V S can substantially modify ground shaking during earthquakes. We apply a novel V S randomization approach to propagate the small-scale heterogeneities of V S to estimate seismic site response within a non-stationary probabilistic framework. The randomization approach generates samples of V S profiles that are used to perform several 1D-GRAs and obtain an averaged site response and related variability. The proposed method is implemented on data recorded at two downhole array sites with different subsurface soil conditions: a soft soil site on Treasure Island (California, United States of America) and a rock outcrop site in Cadarache (South-East France). We show that synthetic surface-to-borehole transfer functions from 1D-GRAs provide an acceptable fit to the empirical transfer functions from low-motion earthquake records and succeed in reproducing most of the site-specific seismic response variability. The remaining mismatch between transfer functions is likely due to insufficient precision on the seismic bedrock and the impedance contrast. The variability in site response is discussed with emphasis on the role of V S small-scale heterogeneities, attenuation, and input motion incidence angle in ground motion variability for the site and soil conditions at both locations.

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USGS2024

Wildland–urban interface wildfire increases metal contributions to stormwater runoff in Paradise, California

The 2018 Camp Fire was a large late-year (November) wildfire that produced an urban firestorm in the Town of Paradise, California, USA, and destroyed more than 18,000 structures. Runoff from burned wildland areas is known to contain ash, which can transport contaminants including metals into nearby watersheds. However, due to historically infrequent occurrences, the effect of wildland urban interface (WUI) fires, such as the Camp Fire, on surface water quality has not been well-characterized. Therefore, this study investigated the effects of widespread urban burning on surface water quality in major watersheds of the Camp Fire area. Between November 2018 and May 2019, 140 surface water samples were collected, including baseflow and stormflow, from burned and unburned watersheds with varying extent of urban development. Samples were analyzed for total and filter-passing metals, dissolved organic carbon, major anions, and total suspended solids. Ash and debris from the Camp Fire contributed metals to downstream watersheds via runoff throughout the storm season. Increases in concentration up to 200-fold were found for metals Cr, Cu, Ni, Pb, and Zn in burned watersheds compared to pre-fire values. Total concentrations of Al, Cd, Cu, Pb, and Zn exceeded EPA aquatic habitat acute criteria by up to 16-fold for up to five months after the fire. To assess possible transport mechanisms and bioavailability, a subset of 18 samples was analyzed using four filters with nominal pore sizes ranging from 0.22 to 1.2 µm to determine the particulate size distribution of metals. Trace and major metals (Al, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) were found mostly associated with larger grain sizes (>0.45 µm), and some metals (Al, Cr, Fe, and Pb) also included a substantial colloidal phase (0.22 µm to 0.45 µm). This study suggests that fires in the wildland-urban interface increase metal concentrations, mainly through particulate driven transport. The metals with largest increases are likely from anthropogenic disaster materials, though biomass ash contributions are also a major contributor to overall water quality. The increase in metals following WUI burning may have adverse ecological impacts.

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USGS2024

Impacts of wildfire runoff on giant kelp in Malibu, California

This study investigates the effects of post-wildfire sediment runoff on giant kelp (Macrocystis pyrifera) populations in Malibu, California, following the 2018 Woolsey Fire. The research utilizes satellite data and the Soil and Water Assessment Tool (SWAT) to assess changes in sediment delivery and its correlation with reduced kelp abundance. Findings indicate a significant decrease in kelp canopy recovery, post-fire, with ongoing limited regrowth up to 2023. This study underscores the critical impacts of wildfire-induced sediment runoff on marine ecosystems and emphasizes the need for tailored coastal management and restoration strategies to mitigate these effects and support the resilience of kelp forests, which are vital for biodiversity and coastal ecosystem services.

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USGS2024

Subduction intraslab-interface fault interactions in the 2022 Mw 6.4 Ferndale, California earthquake sequence

The Mendocino triple junction, the intersection of the Pacific, North American, and Gorda plates, activates a collection of disparate faults that reconcile Cascadia subduction with San Andreas transform motion. The December 20, 2022, Mw 6.4 Ferndale, California earthquake occurred within this complex zone as strike-slip faulting within the subducting Gorda slab. Here, we analyze the seismic and geodetic signatures of the mainshock and aftershock sequence to illuminate its role within complex tectonic surroundings. We find aftershocks on varied fault structures within the uppermost Gorda slab, yet seismicity on the subduction interface itself was notably absent. Nevertheless, we identify small but coherent postseismic deformation that is well modeled by aseismic slip on this interface, likely triggered by stresses generated at the updip limit of coseismic rupture. This sequence demonstrates the potential for interactions between intra-slab earthquakes and slip on the subduction megathrust, highlighting the need to consider this and other subduction zones as coupled systems of interacting faults.

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USGS2024

Geology, coastal geomorphology, and soils of eastern Santa Cruz Island (Limuw), Channel Islands National Park, California, USA

This one-day field trip explores northeastern Santa Cruz Island ( Limuw , in native Chumash), a part of Channel Islands National Park, USA. The geomorphology of eastern Santa Cruz Island has been controlled largely by active tectonics and sea-level fluctuations. The bedrock is Miocene volcanic rock overlain by Miocene shale and siltstone. The island has experienced Quaternary uplift, perhaps due to movement along an offshore thrust fault. Smaller faults are exposed in sea cliffs and have displaced Miocene rocks. Superimposed upon island uplift, there have been Quaternary sea-level fluctuations from interglacial-glacial climate changes. Interglacial high-sea stands are recorded as marine terraces. The last major interglacial period, ~120,000 years ago, left only small remnants of marine terraces. Most evidence of this high-sea stand was eroded away in the Holocene. However, a prominent marine terrace is preserved at 75–120 m above sea level. Some fossil mollusks from the deposits of this terrace, probably reworked, have given ages as old as Pliocene, but most yield ages of 2.6–2.0 Ma. The age and elevation of this terrace indicate a very low rate of tectonic uplift, similar to nearby Anacapa Island. A low uplift rate explains the absence or scarcity of younger terraces, including that of the last interglacial period. Low stands of sea (glacial periods) exposed the insular shelf, rich in carbonate skeletal sand. During glacial periods, these sands were entrained by the wind, deposited as dunes on marine terraces, and cemented into eolianite. Clay-rich Vertisols with silt mantles have developed on eolianites and terraces of the island, partly from in situ weathering, but also from inputs of Mojave Desert dust during Santa Ana wind events. This guide includes stops at Scorpion Anchorage, Cavern Point, and Potato Harbor. It provides insights into the bedrock, coastal geomorphology, fossiliferous marine terraces, eolianite, Vertisols, and the three formations on eastern Santa Cruz Island: the Santa Cruz Island Volcanics, the Monterey Formation, and the Potato Harbor Formation.

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USGS2024

Volcanism and tectonics of young basaltic fields in the eastern California shear zone, California, USA

Circa 12 Ma, there was a fundamental reorganization of magmatism and tectonics in the Mojave Desert, California, USA, from basaltic to rhyolitic fields associated with extensional tectonics to dispersed basaltic monogenetic fields associated with the northwest- or east-striking strike-slip faults. The broad zone of strike-slip faults associated with the San Andreas transform margin stretched east to Arizona, but the high slip-rate central part that is known as the Quaternary eastern California shear zone is the locus of the post–12 Ma volcanism. We compiled a literature review of 29 basaltic fields, conducted detailed and reconnaissance study of several fields, and conducted geochemistry on many. Most of the volcanic fields are near or cut by the long fault systems, but more importantly, in nearly two-thirds of the fields that have scoria cones, the cones are <1 km from one of these faults. Eighteen volcanic fields have geochemistry data, and of the 441 analyses of major elements, 286 are new U.S. Geological Survey data that include comprehensive trace elements. The data are used to compare fields and determine the compositional variations during the formation of each field. Comparisons between fields show that several nearby volcanic fields have similar geochemical compositions and trends compared to distant fields; we suggest that six magmatic clusters formed, some with 200–300 k.y. duration. Spatial patterns change over the 12 m.y. span, with early fields forming in the north and south and the youngest in a central area from Pisgah to Amboy fields. The volume of magma also changed, most notably with a sixfold increase ca. 4 Ma followed by a 2–3 m.y. quiescence. In addition to the fracture control provided by strike-slip faults as magma conduits, we advance arguments for shear melting in the mantle along the most active faults, with secondary controls of local tectonic interactions, to explain spatial and temporal patterns in the fields.

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USGS2024

Advanced quantitative precipitation information: Improving monitoring and forecasts of precipitation, streamflow, and coastal flooding in the San Francisco Bay area

Advanced Quantitative Precipitation Information (AQPI) is a synergistic project that combines observations and models to improve monitoring and forecasts of precipitation, streamflow, and coastal flooding in the San Francisco Bay Area. As an experimental system, AQPI leverages more than a decade of research, innovation, and implementation of a statewide, state-of-the-art network of observations, and development of the next generation of weather and coastal forecast models. AQPI was developed as a prototype in response to requests from the water management community for improved information on precipitation, riverine, and coastal conditions to inform their decision-making processes. Observation of precipitation in the complex Bay Area landscape of California’s coastal mountain ranges is known to be a challenging problem. But, with new advanced radar network techniques, AQPI is helping fill an important observational gap for this highly populated and vulnerable metropolitan area. The prototype AQPI system consists of improved weather radar data for precipitation estimation; additional surface measurements of precipitation, streamflow, and soil moisture; and a suite of integrated forecast modeling systems to improve situational awareness about current and future water conditions from sky to sea. Together these tools will help improve emergency preparedness and public response to prevent loss of life and destruction of property during extreme storms accompanied by heavy precipitation and high coastal water levels—especially high-moisture laden atmospheric rivers. The Bay Area AQPI system could potentially be replicated in other urban regions in California, the United States, and worldwide.

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