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Research about California

Source-linked reports with geographic coverage including California.

At least 865 records · Page 48Linked to original sources

Translational science education through citizen science

Guided by the six elements of Translational Ecology (TE; i.e., decision-framing, collaboration, engagement, commitment, process, and communication), we showcase the first explicit example of a Translational Science Education (TSE) effort in the coastal redwood ecosystem of Humboldt County, CA. Using iNaturalist, a flexible and free citizen science/crowdsourcing app, we worked with students from grade school through college, and their teachers and community, to generate species lists for comparison among 19 school and non-profit locations spanning a range of urbanization. Importantly, this TSE effort resulted in both learning and data generation, highlighting the ability of a TSE framework to connect and benefit both students and researchers. Our data showed that, regardless of the age of the observers, holding organized BioBlitzes added substantially more species to local biodiversity lists than would have been generated without them. In support of current ecological theory, these data showed an urbanization gradient among sites, with rural sites containing fewer non-native species than urban ones. On the education side, qualitative assessments revealed students and educators remained engaged throughout the project. Future projects would also benefit by establishing quantifiable metrics for assessing student learning from project conception. Throughout the project, the fundamentals of TE were followed with repeated interactions and shared objectives developed over time within trusted community relationships. Such positive human interactions can lead new naturalists to think of themselves as champions of their local biodiversity (i.e., as land stewards). We anticipate that such newly empowered and locally expert naturalists will remain committed to land stewardship in perpetuity and that other scientists and educators are inspired to conduct similar work.

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Dispersion and stratification dynamics in the upper Sacramento River deep water ship channel

Hydrodynamics control the movement of water and material within and among habitats, where time-scales of mixing can exert bottom-up regulatory effects on aquatic ecosystems through their influence on primary production. The San Francisco Estuary (estuary) is a low-productivity ecosystem, which is in part responsible for constraining higher trophic levels, including fishes. Many research and habitat-restoration efforts trying to increase primary production have been conducted, including, as described here, a whole-ecosystem nutrient addition experiment where calcium nitrate was applied in the Sacramento River Deep Water Ship Channel (DWSC) to see if phytoplankton production could be increased and exported out of the DWSC. As an integral part of this experiment, we investigated the physical mechanisms that control mixing, and how these mechanisms affect the strength and duration of thermal stratification, which we revealed as critical for controlling phytoplankton dynamics in the relatively turbid upper DWSC. Analysis of a suite of mixing mechanisms and time-scales show that both tidal currents and wind control mixing rates and stratification dynamics in the DWSC. Longitudinal and vertical dispersion increased during periods of high wind, during which wind speed influenced dispersion more than tidal currents. Thermal stratification developed most days, which slowed vertical mixing but was rapidly broken down by wind-induced mixing. Stratification rarely persisted for longer than 24 hours, limiting phytoplankton production in the study area. The interaction between physical mechanisms that control mixing rates, mediate stratification dynamics, and ultimately limit primary production in the DWSC may be useful in informing habitat restoration elsewhere in the Delta and in other turbid aquatic environments.

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Concentrations, loads, and associated trends of nutrients entering the Sacramento-San Joaquin Delta, California

Statistical modeling of water-quality data collected at the Sacramento River at Freeport and San Joaquin River near Vernalis, California, USA, was used to examine trends in concentrations and loads of various forms of dissolved and particulate nitrogen and phosphorus that entered the Sacramento–San Joaquin River Delta (Delta) from upstream sources between 1970 and 2019. Ammonium concentrations and loads decreased at the Sacramento River site from the mid-1970s through 1990 because of the consolidation of wastewater treatment and continuously reduced from the mid-1970s to 2019 at the San Joaquin River site. Current ammonium concentrations are mostly below 4 µM (0.056 mg N L –1 ) at both sites, a concentration above which reductions in phytoplankton productivity or changes in algal species composition may occur. The Sacramento River at Freeport site is located upstream of the Sacramento Regional County Sanitation District’s treatment facility’s discharge point; nutrient water quality there is representative of upstream sources. Inorganic nitrogen (nitrate plus ammonium) concentrations and loading differed at both sites. At the Sacramento River location, concentrations decrease in the summer agricultural season, reducing the molar ratios of nitrogen to phosphorus. In contrast, inorganic nitrogen concentrations increase in the San Joaquin River during the agricultural season as a result of irrigation runoff, increasing the molar ratio of nitrogen to phosphorus. This increase suggests a possible nitrogen limitation in the northern Delta and a phosphorus limitation in the southern Delta, as indicated by the molar ratios of bioavailable nitrogen to bioavailable phosphorus. Planned upgrades to the Sacramento Regional Wastewater Treatment Plant (SRWTP) will reduce inorganic nitrogen inputs to the northern Delta. Consequently, the supply of bioavailable nitrogen throughout the upper estuary should diminish. Source modeling of nitrogen and phosphorus identifies agriculture, atmospheric deposition, and wastewater effluent as sources of total nitrogen in the Central Valley. In contrast, geologic sources, agriculture, and wastewater discharge are the primary sources of phosphorus.

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Multi-model comparison of computed debris flow runout for the 9 January 2018 Montecito, California post-wildfire event

Hazard assessment for post-wildfire debris flows, which are common in the steep terrain of the western United States, has focused on the susceptibility of upstream basins to generate debris flows. However, reducing public exposure to this hazard also requires an assessment of hazards in downstream areas that might be inundated during debris flow runout. Debris flow runout models are widely available, but their application to hazard assessment for post-wildfire debris flows has not been extensively tested. Necessary inputs to these models include the total volume of the mobilized flow, flow properties (either inherent material properties or calibration coefficients), and site topography. Estimates of volume are possible in post-event (“back calculation”) studies, yet before an event, volume is an uncertain quantity. We simulated debris flow runout for the well-constrained 9 January 2018 Montecito event using three models (RAMMS, FLO2D, and D-Claw) to determine the relative importance of volume and flow properties. We broke the impacted area into three domains, and for each model-domain combination, we performed a numerical sampling study in which volume and flow properties varied within a wide, but plausible range. We assessed model performance based on inundation patterns and peak flow depths. We found all models could simulate the event with comparable results. Simulation performance was most sensitive to flow volume and less sensitive to flow properties. Our results emphasize the importance of reducing uncertainty in pre-event estimates of flow volume for hazard assessment.

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Capacity of two Sierra Nevada rivers for reintroduction of anadromous salmonids: Insights from a high-resolution view

Historically, anadromous steelhead Oncorhynchus mykiss and spring-run Chinook Salmon O. tshawytscha used high-elevation rivers in the Sierra Nevada of California but were extirpated in the 20th century by construction of impassable dams. Plans to reintroduce the fish by opening migratory passage across the dams and reservoirs can only succeed if upstream habitats have the capacity to support viable populations of each species. To estimate capacity in the Tuolumne and Merced rivers of the central Sierra Nevada, we used a high-resolution approach based on remote sensing and dynamic habitat modeling. Our results suggested that for both species in both systems, sediment grain sizes would support widespread spawning and the water temperatures, depths, and velocities would generate ample capacity for fry and juveniles. However, the unregulated Merced River was consistently too warm for adult Chinook Salmon to hold in the dry season prior to spawning, while the regulated Tuolumne River maintained a cooler, more stable thermal regime with a capacity for thousands of holding adults. In our high-resolution approach, we also discovered several specific physical controls on life history expression, including thermal constraints on the timing of spawning, hydraulic prompts for downstream migration of fry, divergence of the hydraulic niches of steelhead and Chinook Salmon, and a key but uncertain role for thermal tolerance in adult Chinook Salmon. Our results suggested that steelhead reintroduction could succeed in either system and Chinook Salmon could succeed in the Tuolumne River if passage strategies account for large numbers of migrant fry and juveniles driven downstream by winter storms and snowmelt. The Merced River appeared too warm for adult Chinook Salmon, which raises questions about the current limited understanding of thermal tolerance in holding adults. Our study shows how a high-resolution approach can provide valuable insights on specific limiting factors that must be addressed for reintroduction to succeed.

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Contributed reports of widely felt earthquakes in California, United States: If they felt it, did they report it?

In a recent study, Hough and Martin (2021) considered the extent to which socioeconomic factors influence the numbers and distribution of contributed reports available to characterize the effects of both historical and recent large earthquakes. In this study I explore the question further, focusing on analysis of widely felt earthquakes near major population centers in northern and southern California since 2002. For most of these earthquakes there is a correlation between average household income in a postal ZIP code and the population-normalized rate of responses to the DYFI system. As past studies have demonstrated, there is also a strong correlation between DYFI participation and the severity of shaking. This first-order correlation can obscure correlations with other factors that influence participation. Focusing on five earthquakes between 2011 and 2021 that generated especially uniform shaking across the greater Los Angeles, California, region, response rate varies by two orders of magnitude across the region, with a clear correlation with demographics, and consistent spatial patterns in response rate for earthquakes 10 years apart. While there is no evidence that uneven DYFI participation in California impacts significantly the reliability of intensity data collected, the results reveal that DYFI participation is significantly higher in affluent parts of southern California compared to economically disadvantaged areas.

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Projecting climate dependent coastal flood risk with a hybrid statistical dynamical model

Numerical models for tides, storm surge, and wave runup have demonstrated ability to accurately define spatially varying flood surfaces. However these models are typically too computationally expensive to dynamically simulate the full parameter space of future oceanographic, atmospheric, and hydrologic conditions that will constructively compound in the nearshore to cause both extreme event and nuisance flooding during the 21st century. A surrogate modeling framework of waves, winds, and tides is developed in this study to efficiently predict spatially varying nearshore and estuarine water levels contingent on any combination of offshore forcing conditions. The surrogate models are coupled with a time-dependent stochastic climate emulator that provides efficient downscaling for hypothetical iterations of offshore conditions. Together, the hybrid statistical-dynamical framework can assess present day and future coastal flood risk, including the chronological characteristics of individual flood and wave-induced dune overtopping events and their changes into the future. The framework is demonstrated at Naval Base Coronado in San Diego, CA, utilizing the regional Coastal Storm Modeling System (CoSMoS; composed of Delft3D and XBeach) as the dynamic simulator and Gaussian process regression as the surrogate modeling tool. Validation of the framework uses both in-situ tide gauge observations within San Diego Bay, and a nearshore cross-shore array deployment of pressure sensors in the open beach surf zone. The framework reveals the relative influence of large-scale climate variability on future coastal flood resilience metrics relevant to the management of an open coast artificial berm, as well as the stochastic nature of future total water levels.

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Impacts of a non-indigenous ecosystem engineer, the American beaver (Castor canadensis), in a biodiversity hotspot

Non-native species having high per capita impacts in invaded communities are those that modulate resource availability and alter disturbance regimes in ways that are biologically incompatible with the native biota. In areas where it has been introduced by humans, American beaver ( Castor canadensis ) is an iconic example of such species due to its capacity to alter trophic dynamics of entire ecosystems and create new invasional pathways for other non-native species. The species is problematic in several watersheds within the Southern California-Northern Baja California Coast Ecoregion, a recognized hotspot of biodiversity, due to its ability to modify habitat in ways that favor invasive predators and competitors over the region's native species and habitat. Beaver was deliberately introduced across California in the mid-1900s and generally accepted as non-native to the region up to the early 2000s; however, articles promoting the idea that beaver may be a natural resident have gained traction in recent years, due in large part to the species' charismatic nature rather than by presentation of sound evidence. Here, we discuss the problems associated with beaver disturbance and its effects on conserving the region's native fauna and flora. We refute arguments underlying the claim that beaver is native to the region, and review paleontological, zooarchaeological, and historical survey data from renowned field biologists and naturalists over the past ~160 years to show that no evidence exists that beaver arrived by any means other than deliberate human introduction. Managing this ecosystem engineer has potential to reduce the richness and abundance of other non-native species because the novel, engineered habitat now supporting these species would diminish in beaver-occupied watersheds. At the same time, hydrologic functionality would shift toward more natural, ephemeral conditions that favor the regions' native species while suppressing the dominance of the most insidious invaders.

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Impacts of climate change on groundwater availability and spring flows: Observations from the highly productive Medicine Lake Highlands/Fall River Springs Aquifer System

Medicine Lake Highlands/Fall River Springs Aquifer System, located in northeastern California, is home to some of the largest first-order springs in the United States. This work assesses the likely effects of projected climate change on spring flow. Four anticipated climate futures (GFDL A2, GFDL B1, CCSM4 rcp 8.5, CNRM rcp 8.5) for California, which predict a range of conditions (generally warming and transitioning from snow to rain with variable amounts of total precipitation), are postulated to affect groundwater recharge primarily by changing evapotranspiration. The linkages between climate variables and spring flow are evaluated using a water balance model that represents the physics of evapotranspiration and recharge, the Basin Characterization Model. Three of the four climate scenarios (GFDL A2, GFDL B1, CCSM4 rcp 8.5) project that by the year 2100, groundwater recharge (and consequently decreased spring flow) will decrease by 27%, 21%, and 9%, respectively. The fourth scenario (CNRM rcp 8.5) showed an increase in recharge of 32% due to a significant increase in precipitation (27%). Evapotranspiration increases due to a shift in the type of precipitation and a longer growing season. While the likelihood of each scenario is outside the scope of this work, unless total precipitation increases dramatically in the future, increased temperatures and decreasing precipitation will likely result in reduced spring flows, along with warmer water temperatures in downstream habitats.

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Water and sediment chemistry of selected existing and potential habitats of the Mohave tui chub, Mojave National Preserve, California, 2018

The Mohave tui chub ( Siphateles bicolor mohavensis ) was nearly extirpated from the Mojave River drainage in California by the mid-twentieth century and was listed as endangered in 1970. A source population of Mohave tui chub exists at MC Spring in Zzyzx, California, and has been used for several re-establishment efforts in previous decades. Two potential habitats in the Mojave National Preserve with perennial sources of water were identified by the National Park Service as candidates for additional Mohave tui chub re-establishment: West Pond and Rainbow Wells Pond. West Pond, an artificial pond at Zzyzx near MC Spring, contained a population of Mohave tui chub that died off in 1985 because of changes in water quality. The pond was rehabilitated in the past several years through re-excavation and by pumping fresh groundwater into the pond. Rainbow Wells Pond is an abandoned excavated mine site in the Cima Dome area. The bottom of the excavation intersects the water table, forming a pond. In cooperation with the National Park Service, the U.S. Geological Survey monitored water-quality conditions at West Pond and Rainbow Wells Pond for 1 year to characterize the suitability of spring habitat for re-establishment of Mohave tui chub populations. Data were also collected at three existing Mohave tui chub habitats in Mojave National Preserve to provide further information on the range of acceptable physical and chemical conditions. Initial water-quality results at West Pond indicate the pond has similar water quality as existing Mohave tui chub habitats. Initial water-quality results at Rainbow Wells Pond indicate the dissolved oxygen concentrations and springtime water temperatures are less than the long-term tolerable ranges for Mohave tui chub.

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Three-dimensional electrical resistivity characterization of Mountain Pass, California and surrounding region

The Sulphide Queen carbonatite deposit at Mountain Pass in southeast California is a world class rare earth element (REE) resource. This study images electrical resistivity structure of the REE deposit and surrounding area to characterize resources under cover. An east-west elongated grid (35 × 15 km) of 65 wideband magnetotelluric stations spanning from eastern Shadow Valley to eastern Ivanpah Valley were collected and modeled in three-dimensions (3-D). Gravity, aeromagnetic, and geologic data are used to inform interpretation of structures in the resistivity model, including the following observations. Shadow Valley is filled with conductive sediment that locally dips southward to a depth of 1 km. The Kingston Range-Halloran Hills detachment fault dips westward at ∼15 degrees. The REE deposit is a moderate low resistivity zone dipping southwest to a possible depth of ∼1 km, and is bounded by the North and South faults and bisected by the Middle fault. Ivanpah Dry Lake is underlain by a north striking southward dipping sedimentary basin. Two possible zones of mineralization are observed in Ivanpah Valley, one along the western edge of Ivanpah Dry Lake and one on the western edge of valley along a new inferred fault. The brittle-ductile transition is imaged at ∼10 km below mean sea level. No deep electrically conductive structures are imaged to be related to the REE deposit likely due to the complex geologic history of the Mojave terrane. Future studies should regional target Proterozoic rocks and search within for geophysical signatures similar to Mountain Pass.

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Testing models of Laramide orogenic initiation by investigation of Late Cretaceous magmatic-tectonic evolution of the central Mojave sector of the California arc

The Mojave Desert region is in a critical position for assessing models of Laramide orogenesis, which is hypothesized to have initiated as one or more seamounts subducted beneath the Cretaceous continental margin. Geochronological and geochemical characteristics of Late Cretaceous magmatic products provide the opportunity to test the validity of Laramide orogenic models. Laramide-aged plutons are exposed along a transect across the Cordilleran Mesozoic magmatic system from Joshua Tree National Park in the Eastern Transverse Ranges eastward into the central Mojave Desert. A transect at latitude ∼33.5°N to 34.5°N includes: (1) the large upper-crustal Late Cretaceous Cadiz Valley batholith, (2) a thick section of Proterozoic to Jurassic host rocks, (3) Late Cretaceous stock to pluton-sized bodies at mesozonal depths, and (4) a Jurassic to Late Cretaceous midcrustal sheeted complex emplaced at ∼20 km depth that transitions into a migmatite complex truncated along the San Andreas fault. This magmatic section is structurally correlative with the Big Bear Lake intrusive suite in the San Bernardino Mountains and similar sheeted rocks recovered in the Cajon Pass Deep Scientific Drillhole. Zircon U-Pb geochronology of 12 samples via secondary ionization mass spectrometry (SIMS) (six from the Cadiz Valley batholith and six from the Cajon Pass Deep Scientific Drillhole) indicates that all Cretaceous igneous units investigated were intruded between 83 and 74 Ma, and Cajon Pass samples include a Jurassic age component. A compilation of new and published SIMS geochronological data demonstrates that voluminous magmatism in the Eastern Transverse Ranges and central Mojave Desert was continuous throughout the period suggested for the intersection and flat-slab subduction of the Shatsky Rise conjugate deep into the interior of western North America. Whole-rock major-element, trace-element, and isotope geochemistry data from samples from a suite of 106 igneous rocks represent the breadth of Late Cretaceous units in the transect. Geochemistry indicates an origin in a subduction environment and intrusion into a crust thick enough to generate residual garnet. The lack of significant deflections of compositional characteristics and isotopic ratios in igneous products through space and time argues against a delamination event prior to 74 Ma. We argue that Late Cretaceous plutonism from the Eastern Transverse Ranges to the central Mojave Desert represents subduction zone arc magmatism that persisted until ca. 74 Ma. This interpretation is inconsistent with the proposed timing of the docking of the Shatsky Rise conjugate with the margin of western North America, particularly models in which the leading edge of the Shatsky Rise was beneath Wyoming at 74 Ma. Alternatively, the timing of cessation of plutonism precedes the timing of the passage of the Hess Rise conjugate beneath western North America at ca. 70–65 Ma. The presence, geochemical composition, and age of arc products in the Eastern Transverse Ranges and central Mojave Desert region must be accounted for in any tectonic model of the transition from Sevier to Laramide orogenesis.

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Enhancing marsh elevation using sediment augmentation: A case study from southern California, USA

Tidal marshes are an important component of estuaries that provide habitat for fish and wildlife, protection from flooding, recreation opportunities, and can improve water quality. Critical to maintaining these functions is vertical accretion, a key mechanism by which tidal marshes build elevation relative to local sea level. The beneficial use of dredged material to build marsh elevations in response to accelerating sea level rise has gained attention as a management action to prevent habitat loss over the coming decades. In January 2016, a sediment augmentation project using local dredged material was undertaken at Seal Beach National Wildlife Refuge in Anaheim Bay, California, USA, to benefit tidal marsh habitat and the listed species it supports. The application process added 12,900 cubic meters of sediment with an initial, average 22-cm gain in elevation over a 3.2-hectare site. Due to sediment characteristics and higher than anticipated elevations in some areas, vegetation colonization did not occur at the expected rate; therefore, adaptive management measures were undertaken to improve hydrology of the site and facilitate vegetation colonization. More case studies that test and monitor sea level adaptation actions are needed to assist in the planning and implementation of climate-resilient projects to prevent coastal habitat loss over the coming century.

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A basin-scale approach to estimating recharge in the desert: Anza-Cahuilla groundwater basin, CA

The Anza-Cahuilla groundwater basin located mainly in the semi-arid headwaters of the Santa Margarita River watershed in southern California is the principle source of groundwater for a rural disadvantaged community and two Native American Tribes, the Ramona Band of Cahuilla and the Cahuilla. Groundwater in the study area is derived entirely from precipitation and managing groundwater sustainably requires an accurate assessment of the water balance components, yet long-term estimates do not exist. Demand for groundwater in the region has increased and groundwater quality has decreased due to population growth and increased irrigated cropland. To characterize monthly long-term natural recharge and runoff estimates, a physically-based water balance model (Basin Characterization Model) was locally calibrated and validated using nearby streamgages and published estimates of climatic and hydrologic variables. The average modeled annual recharge and runoff from 1981 to 2010 was 5.4 × 10 6 and 1.2 × 10 7 m 3 , respectively, for the study area. Recharge and runoff do not reliably occur in large amounts every year and recharge rarely occurs in the groundwater basin footprint. These long-term estimates can be used by water managers, stakeholders, and Native American Tribes to develop plans for sustainable management of future water resources, and as inputs to a three-dimensional groundwater model.

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Variability in wildland fuel patches following high-severity fire and post-fire treatments in the northern Sierra Nevada

Surface fuel loads are highly variable in many wildland settings, which can have many important ecological effects, especially during a wildland fire. This variability is not well described by a single metric (e.g. mean load), so quantifying traits such as variability, continuity and spatial arrangement will help more precisely describe surface fuels. This study measured surface fuel variability in the northern Sierra Nevada of California following a high-severity fire that converted a mixed-conifer forest to shrub-dominant vegetation, both before and after a subsequent shrub removal treatment conducted as site preparation for reforestation. Data were collected on vegetation composition, spatial arrangement and biomass load of the common surface fuel components (1–1000-h woody fuel, litter, duff and shrubs). Mean shrub patch length decreased significantly from 9.25 to 1.0 m and mean dead and down surface fuel load decreased significantly from 131.4 to 73.4 Mg ha −1 . Additionally, probability of encountering a continuous high fuel load segment decreased after treatment. This work demonstrates a method of quantifying important spatial characteristics of surface fuel that could be used in the next generation of fire behaviour models and provides metrics that land managers may consider when designing post-fire reforestation treatments.

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Post-drought groundwater storage recovery in California’s Central Valley

Groundwater depletion is a major threat to agricultural and municipal water supply in California's Central Valley. Recent droughts during 2007–2009 and 2012–2016 exacerbated chronic groundwater depletion. However, it is unclear how much groundwater storage recovered from drought-related overdrafts during post-drought years, and how climatic conditions and water management affected recovery times. We estimated groundwater storage change in the Central Valley for April 2002 through September 2019 using four methods: GRACE satellite data, a water balance approach, a hydrologic simulation model, and monitoring wells. We also evaluated the sensitivity of drought recovery to different climate scenarios (recent climate ± droughts and future climate change scenarios: 20 GCMs and 2 RCPs) using water balance method and statistical sampling of historical climate data. Estimated Central Valley groundwater loss during the two droughts ranged from 19 km 3 (2007–2009) to 28 km 3 (2012–2016) (median of four methods). Median aquifer storage recovery was 34% and 19% of the overdraft during the 2010–2011 and 2017–2019 post-drought years, respectively. Numerical experiments show that recovery times are sensitive to climate forcing, with longer recovery times for a future climate scenario that replicate historical climatology relative to historical forcing with no droughts. Overdraft recovery times decrease by ∼2× with implementation of pumping restrictions (30th to 50th percentiles of historical groundwater depletion) to constrain groundwater depletion relative to no restrictions with a no-drought future climatology. This study highlights the importance of considering water management implications for future drought recoveries within the context of climate change scenarios.

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Experiences in LP-IoT: EnviSense deployment of remotely reprogrammable environmental sensors

The advent of Low Power Wide Area Networks (LPWAN) has improved the feasibility of wireless sensor networks for environmental sensing across wide areas. We have built EnviSense, an ultra-low power environmental sensing system, and deployed over a dozen of them across two locations in Northern California for hydrological monitoring applications with the U.S. Geological Survey (USGS). This paper details our experiences with the design and implementation of this system across two years, including six months of continuous measurement in the field. We describe the lessons learned for deployment planning, remote device management and programming, and system co-design with a domain-expert from the USGS.

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The HayWired Earthquake Scenario—Societal Consequences

The HayWired earthquake scenario, led by the U.S. Geological Survey (USGS), anticipates the impacts of a hypothetical moment magnitude 7.0 earthquake on the Hayward Fault. The fault runs along the east side of California’s San Francisco Bay and is among the most active and dangerous in the United States, passing through a densely urbanized and interconnected region. A scientifically realistic scenario is one way to learn from a large earthquake before one occurs in the bay region. The USGS and its partners in the HayWired Coalition are working to energize residents and businesses to engage in new and ongoing efforts to prepare the region for such a future earthquake.

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