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There is a surge of interest in reaching social and environmental justice in California's disadvantaged communities by governments, nongovernmental organizations, and academia. However, actions tak...

We studied the sequence of climatic and hydrological events associated with the formation of peat during the Holocene, using pollen, diatoms and environmental magnetism from peat cores at three locations in the Sacramento-San Joaquin Delta of California: Browns Island, Franks Wetland and Webb Track Levee. Our data show that peat first formed under relatively dry conditions in a freshwater environment before 6.5 ka BP. Subsequently, pollen accumulation rates were highest prior to intervals with high peat accretion rates but are inversely correlated with organic accumulation rate. Intervals of high peat accretion were preceded by pulses of terrigenous material. During intensive drainage episodes, high flows delivered abundant, coarser-grained sediment to the marshes, which inundated the existing vegetation and decreased the rate of biochemical decay. The build-up of undecomposed organic material led to the acceleration of peat accretion. Our data support the rarely discussed hypothesis that most of the peat in the Sacramento-San Joaquin Delta formed in freshwater marshes that were fed by rivers draining from the Sierra Nevada, rather than in saltwater wetlands resulting from sea level rise and estuarine submergence. This result has important implications for current attempts to remediate and restore the Delta ecosystem.

Wintertime episodes of high aerosol concentrations occur frequently in urban and agricultural basins and valleys worldwide. These episodes often arise following development of persistent cold-air pools (PCAPs) that limit mixing and modify chemistry. While field campaigns targeting either basin meteorology or wintertime pollution chemistry have been conducted, coupling between interconnected chemical and meteorological processes remains an insufficiently studied research area. Gaps in understanding the coupled chemical–meteorological interactions that drive high-pollution events make identification of the most effective air-basin specific emission control strategies challenging. To address this, a September 2019 workshop occurred with the goal of planning a future research campaign to investigate air quality in western U.S. basins. Approximately 120 people participated, representing 50 institutions and five countries. Workshop participants outlined the rationale and design for a comprehensive wintertime study that would couple atmospheric chemistry and boundary layer and complex-terrain meteorology within western U.S. basins. Participants concluded the study should focus on two regions with contrasting aerosol chemistry: three populated valleys within Utah (Salt Lake, Utah, and Cache Valleys) and the San Joaquin Valley in California. This paper describes the scientific rationale for a campaign that will acquire chemical and meteorological datasets using airborne platforms with extensive range, coupled to surface-based measurements focusing on sampling within the near-surface boundary layer, and transport and mixing processes within this layer, with high vertical resolution at a number of representative sites. No prior wintertime basin-focused campaign has provided the breadth of observations necessary to characterize the meteorological–chemical linkages outlined here, nor to validate complex processes within coupled atmosphere–chemistry models.

Groundwater total dissolved solids (TDS) distribution was mapped with a three-dimensional (3D) model, and it was found that TDS variability is largely controlled by stratigraphy and geologic structure. General TDS patterns in the San Joaquin Valley of California (USA) are attributed to predominantly connate water composition and large-scale recharge from the adjacent Sierra Nevada. However, in smaller areas, stratigraphy and faulting play an important role in controlling TDS. Here, the relationship of stratigraphy and structure to TDS concentration was examined at Poso Creek Oil Field, Kern County, California. The TDS model was constructed using produced water TDS samples and borehole geophysics. The model was used to predict TDS concentration at discrete locations in 3D space and used a Gaussian process to interpolate TDS over a volume. In the overlying aquifer, TDS is typically

Mercury emitted to the atmosphere has a long residence time (up to a year) and can travel long distances before being deposited to land or ocean surfaces. The objective of this study were to evaluate the total gaseous mercury (TGM) ambient levels in the San Joaquin, Queretaro, mining region and to observe whether the TGM emissions from mining activity impact other regions of the country due to its dispersion. TGM was measured using an automatic Tekran model 2537A air mercury analyzer; the monitoring was carried out during March, April, and May 2015. From the ambient measurements carried out, the 8-h average concentrations range from 67 to 74 ng/m3, while the monthly averages for these three months were from 40 to 41 ng/m3 (1.3 ± 0.4 ng/m−3). Mercury concentrations did not vary significantly during the 24-h survey measurement, reporting an average value of 40.3 ± 0.75 ng/m3 (40.1 ng/m3 averages) and an extreme value of 235 ng/m3. In order to identify the possible TGM fate, a set of trajectories was obtained for different time periods using the wind fields from the Water Research and Forecasting (WRF) meteorological model and a dispersion was performed by using the CALPUFF model driven by the WRF-CALMET model to identify the TGM levels in the site vicinity.

The San Joaquin antelope squirrel (Ammospermophilus nelsoni) is endemic to the San Joaquin Desert of California. It has been listed as Threatened by the state of California since 1980 due to profound habitat loss, but a paucity of information could limit conservation efforts for this species. We examined data collected each August during 1997–2006 to determine whether A. nelsoni population attributes differed between grazed and ungrazed study plots. We found that sex ratios, mean weights, percentage of reproductive males, number of young, yearly survival, longevity, overall survivorship, and population growth trajectories all were similar between grazed and ungrazed plots. In general, sex ratios were even, males were heavier than females, some males were reproductive in August (although most females were not), and the number of young was inversely related to residual dry matter. We also found that we captured most individuals only once, but we captured a few squirrels for up to for 5 years, and the populations on both grazed and ungrazed plots were growing during the 10-year study. Our study was only the second long-term investigation of this species and the information is needed for further conservation and recovery efforts.

The San Joaquin antelope squirrel (Ammospermophilus nelsoni) is one of five species in the genus and has the most restricted range of the four mainland antelope squirrels, occurring only in the San Joaquin Desert of California. Despite being state-listed as Threatened since 1980, few studies have been conducted on A. nelsoni, especially ecological studies, which hampers recovery efforts. We conducted a radio-telemetry study in 2002 of 19 males on the Lokern Natural Area in the southwestern portion of the San Joaquin Desert. Based on 100% Minimum Convex Polygons (MCP), home ranges varied from 1.25–14.5 ha with a mean of 5.93 ha (± 0.90 standard error). The average daily distance traveled by these 19 males was 128.5 m (range, 71.4–224.5) and the average greatest distance travelled in a day was 313.0 m, with some traveling > 0.5 km. Our data are useful to further refine the estimates of home range and movements of this neglected protected species, but in the future, better home range studies are needed that span multiple years, include both sexes, and occur at sites across its range.

San Joaquin kit foxes (Vulpes macrotis mutica) are federally endangered and California threatened, primarily due to profound habitat loss. Kit foxes are obligate den users and in some locations den availability may be limited due to natural or anthropogenic factors. We conducted a study during 2001–2004 to determine whether kit foxes would use artificial dens, and if so, whether they exhibited a preference for den designs or construction materials. We tested six different den designs, four different construction materials, and two different chamber types. We constructed 34 dens in 12 locations in Bakersfield, CA. We conducted 9,271 den checks and detected kit foxes or their sign on 1,198 of those checks. Kit foxes may not have found one of the locations, but kit foxes used (i.e., entered) 29 of the 31 dens at the other 11 locations. Kit foxes did not exhibit preferential use of any designs, materials, or chamber types. Internal conditions (i.e., temperature and relative humidity) within artificial dens can provide thermoregulatory and moisture conservation benefits to foxes, although these benefits were not as strong as those provided by natural dens. At least nine other species were documented using the artificial dens, including some that might compete with kit foxes. San Joaquin kit foxes readily used artificial dens and clearly such dens can be used to mitigate den losses or to enhance habitat for kit foxes. Due to lower cost and ease of installation, we recommend installing two-entrance dens constructed of high-density polyethylene plastic with an irrigation valve box for a subterranean chamber.

A critical component of water-resources management in the irrigated agriculture landscape, particularly those landscapes dependent on groundwater availability, is determining groundwater recharge rates from streams and other channels. In California, flows in many such channels are “controlled” by upstream reservoir releases to meet downstream urban, irrigation and environmental water requirements. Seepage volumes from these channels and how they might vary during controlled release periods is a key component of meeting downstream riparian and groundwater-pumping needs. Understanding annual seepage from streamflow channels is also important in developing water budgets as part of the management of groundwater resources under the Sustainable Groundwater Management Act (SGMA) in California. However, direct measurements of channel seepage rates are infrequent or unavailable, and these rates, or associated volumes, are most often only estimated. Here we describe direct point- and reach-scale field measurements of channel seepage rates in Lower Putah Creek (Solano County) and in distribution lateral channels of the Oakdale Irrigation District on the east side of the San Joaquin Valley (San Joaquin and Stanislaus counties). We measured overall average seepage rates of about 2 feet (610 mm) per day at both locations and determined how these rates varied spatially and temporally during the summer when channel flows are controlled for downstream requirements.

The San Joaquin antelope squirrel (Ammospermophilus nelsoni: SJAS) is listed as Threatened pursuant to the California Endangered Species Act due to profound habitat loss throughout its range in the San Joaquin Desert in California. Habitat loss is still occurring and critical needs for SJAS include identifying occupied sites, quantifying optimal habitat conditions, and conserving habitat. Our objectives were to (1) conduct surveys to identify sites where SJAS were present, (2) assess habitat attributes on all survey sites, (3) generate a GIS-based model of SJAS habitat suitability, (4) use the model to determine the quantity and quality of remaining habitat, and (5) use these results to develop conservation recommendations. SJAS were detected on 160 of the 326 sites we surveyed using automated camera stations. Sites with SJAS typically were in arid upland shrub scrub communities where desert saltbush (Atriplex polycarpa) or jointfir (Ephedra californica) were the dominant shrubs, although shrubs need not be present for SJAS to be present. Sites with SJAS usually had relatively sparse ground cover with >10% bare ground and Arabian grass (Schismus arabicus) was the dominant grass. SJAS were more likely to occur on sites where kangaroo rats (Dipodomys spp.) were present and burrow abundance was greater, but SJAS were less likely to be present on sites with California ground squirrels (Otospermophilus beecheyi). Based on our habitat suitability model, an estimated 5,931 km2 of high or moderately high quality habitat and 4,753 km2 of lower quality habitat remain. To conserve SJAS, we recommend (1) conducting additional SJAS surveys on sites not surveyed but with suitable habitat, (2) conserving unprotected lands with suitable habitat, (3) managing vegetation on occupied sites if necessary, (4) restoring disturbed lands to increase suitability for SJAS, and (5) conducting translocations of SJAS to unoccupied sites with suitable habitat.

This study utilizes satellite data to investigate water quality conditions in the San Francisco Estuary and its upstream delta, the Sacramento-San Joaquin River Delta. To do this, this study derives turbidity from the European Space Agency satellite Sentinel-2 acquired from September 2015 to June 2019 and conducts a rigorous validation with insitu measurements of turbidity from optical sensors at continuous monitoring stations. This validation includes 965 matchup comparisons between satellite and insitu sensor data across 22 stations, yielding R 2 = 0.63 and 0.75 for Nephelometric Turbidity Unit and Formazin Nephelometric Unit (FNU) stations, respectively. This study then applies remote sensing to evaluate patterns in turbidity during the Suisun Marsh Salinity Control Gates Action ("Gates action"), a pilot study designed to increase habitat access and quality for the endangered Delta Smelt. The basic strategy was to direct more freshwater into Suisun Marsh, creating more low salinity habitat that would then have higher (and more suitable) turbidity than upstream river channels. For all seven acquisitions considered from June 29 to September 27, 2018, turbidity conditions in Bays and Sloughs subregions were consistently higher (and more suitable) (26-47 FNU) than what was observed in the upstream River region (13-25 FNU). This overall pattern was observed when comparing images acquired during similar tidal stages and heights.

Drought vulnerability studies in the United States primarily focus on biophysical and economic indicators and overlook the multiple ways drought is experienced socially. This research examines the human dimensions of drought through narratives of drought vulnerability in the agricultural communities of California’s San Joaquin Valley during the 2012–2016 drought. Four narratives are identified that reveal the lived experiences and local knowledges of drought as well as the multiple understandings of the political, economic, social, and environmental processes that produce drought vulnerability. The narratives explain the production of drought across long timescales that include both memories of historical events as well as visions of desired futures for the region. Who is vulnerable and why differs across the narratives, with each narrative offering competing understandings for how the relationships between water, agriculture, labor, and rural communities create drought vulnerability. Which narrative becomes dominant and embedded in water governance has impacts on the practice of agriculture as well as social and environmental justice for farmworkers and rural community members.

Largemouth bass (LMB; Micropterus salmoides) recruitment is limited by a critical developmental period during early life stages, but this mechanism may be less important within non-native habitats. We conducted boat electrofishing surveys in four tidal lakes of California’s Sacramento–San Joaquin Delta (SSJD) from 2010 to 2011 to describe introduced LMB recruitment dynamics. We evaluated growth, proximate composition, and health indices of young-of-the-year (YOY) LMB among tidal lakes and developed an integrated count model to determine how factors known to affect LMB recruitment shape SSJD population structure. Our results show a mismatch among growth, nutrition, and YOY abundance, where the tidal lake with the most abundant and fastest-growing LMB had the poorest nutritional status. The warm winter water temperatures and lack of a hatching-cohort growth advantage suggests overwinter starvation plays a less important role in SSJD LMB recruitment than in many native LMB habitats. Collectively, our results suggest that habitat characteristics (submerged aquatic vegetation) and not overwinter mortality shapes SSJD LMB population structure, a mechanism consistent with contemporary hypotheses about the altered fish community structure of the SSJD.

In California’s San Joaquin Valley, some researchers are turning political to address the social determinants of health. In California’s San Joaquin Valley, some researchers are turning political to address the social determinants of health.

The San Joaquin Valley in Central California is a semiarid region that is known to be highly endemic for coccidioidomycosis infections in high-risk groups. Coccidioidomycosis, also known as valley fever, is caused by the fungal spore Coccidioides, which can be found in the soil in arid and semiarid regions in the Southwest United States and parts of Central and South America. When soil is disturbed through excavation, agricultural activities, or with any other soil movement, these activities can release the fungal spores into air; people who are in close proximity can potentially inhale them. The purpose of this clinical case study is to address the need for coccidioidomycosis infection awareness and educate primary care providers to determine the diagnostic reasoning and process. A simple algorithm and template will aid them to accurately diagnose and treat patients with valley fever earlier in the disease process., Highlights • This article includes education for primary care providers on the pathophysiology, clinical symptoms, diagnostics, and treatments of valley fever. • Evidenced-based research is presented on occupational exposure to dust from soil disturbing activities. • Primary care providers are educated about valley fever and dust exposure using the acronym COCCI (Consider the diagnosis, Order the right tests, Check for risk factors, Check for complications, and Initiate management).

Nitrous oxide (N2O) is a long-lived greenhouse gas that also destroys stratospheric ozone. N2O emissions are uncertain and characterized by high spatiotemporal variability, making individual observations difficult to upscale, especially in mixed land use source regions like the San Joaquin Valley (SJV) of California. Here, we calculate spatially integrated N2O emission rates using nocturnal and convective boundary-layer budgeting methods. We utilize vertical profile measurements from the NASA DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) campaign, which took place January-February, 2013. For empirical constraints on N2O source identity, we analyze N2O enhancement ratios with methane, ammonia, carbon dioxide, and carbon monoxide separately in the nocturnal boundary layer, nocturnal residual layer, and convective boundary layer. We find that an established inventory (EDGAR v4.3.2) underestimates N2O emissions by at least a factor of 2.5, that wintertime emissions from animal agriculture are important to annual totals, and that there is evidence for higher N2O emissions during the daytime than at night.

Climate change can potentially have great impacts on wintertime precipitation and stagnant conditions, which are critical for both water resources and wintertime particulate matter (PM), in California. This study utilizes the Weather Research and Forecasting model to dynamically downscale a bias-corrected coarse-resolution global climate model dataset from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to a grid size of 4 × 4 km2 over California for a present (2003–2012) and a future (2046–2055) decade. Compared to the present climate, an increase in 2-m temperature (up to 2 K) and water vapor mixing ratio (up to 1 g/kg) and a decrease in planetary boundary layer height (up to 80 m) are projected by the 2050s for the entire state of California. The number of stagnant days over the San Joaquin Valley is expected to increase by approximately 6% in the future decade, indicating potential exacerbation of the winter PM issue in this region. The wintertime precipitation is projected to increase by up to 50% in northern California and, conversely, to decrease by up to 40% in southern California during 2046–2055. The solid phase precipitation is projected to decrease over mountain ranges with lower elevations despite an overall increase in total precipitation, while it is projected to increase over the eastern side of the Sierra Nevada with elevation over 2 km.

Sveite [KAl7(NO3)4(OH)16Cl2·8H2O] first described from Venezuela and material recently collected from northern California have similar X-ray diffraction patterns and chemical compositions. The main difference in the chemical composition is the absence of significant chlorine and sulfate in the sveite from California. The changes observed by X-ray diffraction upon hydration and the SEM images of the crystals suggest a layered atomic structure. Water-extractable NO3 in the Venezuelan sveite sample is isotopically enriched in δ15N and δ18O and likely was affected by the microbial process of denitrification. In contrast, the extractable nitrate from the California sveite is less isotopically enriched than the Venezuelan mineral and there is only modest evidence that denitrification had affected its isotopic composition. Overall, the nitrate in the California sveite is isotopically similar to nitrate present in acidic soils overlying the mineral occurrence, suggesting a general biogenic source of uric acid from bird feces for the mineral-bound nitrogen.

Highlights • Political disenfranchisement and racism form the bedrock of rural California geography. • Environmental justice organizing has built a progressive base in the San Joaquin Valley. • Control over local governance can scale up and strengthen environmental justice. • Opposing populisms in Kern County, CA are situated distinctly in neoliberal crisis. • Resistance to farmworker disposability is being expressed in environmental terms.

Unconventional opal-A and opal-CT diatomaceous reservoirs in the Monterey Formation of the San Joaquin Valley in California have produced for more than 30 yr. These opal-A reservoirs are characterized by high porosity (>50%) and low permeability ( 45% [Cymric and McKittrick fields]) or are very thick (>1000 ft thick [Lost Hills field]). These insights provide general guidance about characterization of unconventional diatomaceous reservoirs and the identification of factors that most dramatically influence performance.

Nitrate is one of the most abundant contaminants in groundwater globally, in the United States, and in California (CA). We studied well construction information, water chemistry, stable isotopes, and noble gases to understand how groundwater travel time and recharge source and mechanism control nitrate concentrations in domestic wells in the San Joaquin Valley (SJV), CA, a large semiarid, irrigated agricultural region. Using nonparametric statistics, we find a decreasing trend in nitrates with groundwater travel time and well depth. Samples collected from wells that are closer to rivers and that show indications of river water recharge, either low recharge temperature or low δ18O signature, have lower concentrations of nitrates than samples with isotopic signatures indicating mixed source or local precipitation recharge. The curbing effect of river water recharge on nitrate concentrations in domestic wells is similar for direct river recharge and water applied as irrigation. This suggests that irrigation with river water also has a diluting effect that reduces the concentration of nitrate found in groundwater. This conclusion supports the idea that flood-managed aquifer recharge may be considered for remediation of groundwater nitrate when designing replenishment of aquifers.

The Guanzhong Basin (GZB) of northwest China is examined as a mega-region containing the mega-city of Xi’an. The concept of a “mega-region” is more accurate than that of a “mega-city” for air quality management as there is an interaction between urban and non-urban emissions. Parallels are drawn between the GZB and the San Joaquin Valley (SJV) mega-region of central California for excessive wintertime PM2.5 concentrations. Long-term chemical composition measurements show the usual high levels of organic and elemental carbon, minerals, sulfate, nitrate, and ammonium. Wintertime provides prolonged high pressure systems in both areas punctuated by unstable precipitation events. Sluggish nighttime winds allow pollutants such as ammonia from distant agricultural operations, to mix with urban pollutants, sometimes serving as a reactor to create secondary sulfates and nitrates, and possibly some secondary organic compounds. A shallow surface layer forms at night in the SJV and GZB that couples to an upper level inversion after sunrise, allowing pollutants accumulated aloft to mix to the surface. Although current air quality management strategies have focused on urban emissions, and PM2.5 levels are on a downward trend, future management efforts must consider reducing emissions from a variety of sources in the larger region of these basins. Agricultural emissions are important in the SJV, but are just being addressed in the GZB. Tactics developed for the SJV would probably be effective in other areas of the world with similar emissions, topography, and meteorology. Experiments related to agricultural NOx emissions, emission inventory enhancements, source apportionment, and estimates of precursor limitations for ammonium nitrate formation, have been conducted in the SJV that can be tested in the GZB.

Coccidioidomycosis (Valley fever) is an infection caused by the soil-dwelling fungus Coccidioides spp., which usually manifests as a mild self-limited respiratory illness or pneumonia but can result in severe disseminated disease and, rarely, death (1,2). In California, coccidioidomycosis incidence increased nearly 800% from 2000 (2.4 cases per 100,000 population) to 2018 (18.8) (2-4). The California Department of Public Health (CDPH) reports statewide and county-level coccidioidomycosis incidence annually; however, a comprehensive regional analysis has not been conducted. Using California coccidioidomycosis surveillance data during 2000-2018, age-adjusted incidence rates were calculated, and coccidioidomycosis epidemiology was described in six regions. During 2000-2018, a total of 65,438 coccidioidomycosis cases were reported in California; median statewide annual incidence was 7.9 per 100,000 population and varied by region from 1.1 in Northern and Eastern California to 90.6 in the Southern San Joaquin Valley, with the largest increase (15-fold) occurring in the Northern San Joaquin Valley. When analyzing demographic data, which was available for >99% of cases for sex and age and 59% of cases for race/ethnicity, median annual incidence was high among males (10.2) and Black persons (9.0) consistently across all regions; however, incidence varied among Hispanics and adults aged 40-59 years by region. Tracking these surveillance data at the regional level reinforced understanding of where and among what demographic groups coccidioidomycosis rates have been highest and revealed where rates are increasing most dramatically. The results of this analysis influenced the planning of a statewide coccidioidomycosis awareness campaign so that the messaging, including social media and TV and radio segments, focused not only on the general population in the areas with the highest rates, but also in areas where coccidioidomycosis is increasing at the fastest rates and with messaging targeted to groups at highest risk in those areas.

Providing the public with relevant and reliable statistical information about the impact of COVID-19 on vulnerable populations is a crucial weapon in effective public health system response This article examines the reporting challenges confronted by local public health agencies based on a case study of farmworker communities of the San Joaquin Valley, Eastern Coachella Valley, and Salinas Valley The analysis includes a quantitative estimate of the impact COVID-19 has on farmworker households and highlights how socioeconomic factors and housing conditions give rise to health disparities The importance of local data collection and reporting as the foundation for a national epidemiological tracking system is emphasized Current shortcomings stemming from flawed national guidance and local political pressures are noted The discussion includes detailed recommendation for improved reporting including: more systematic tabulations of available data, an expanded set of indicators to monitor public health system response, promising approaches to improve representativeness of test-derived data on COVID-19 by making it easier to access testing and support services, coupled with messaging to broaden farmworkers' and other socio-politically marginalized populations' willingness to seek testing Understanding the challenges faced and lessons learned in the San Joaquin Valley region have practical implications for a wide range of countries © 2020 - IOS Press and the authors All rights reserved

Xylella fastidiosa is a vector-transmitted bacterial plant pathogen that affects a wide array of perennial crops, including grapevines (Pierce’s disease). In the southern San Joaquin Valley of California, epidemics of Pierce’s disease of grapevine were associated with the glassy-winged sharpshooter, Homalodisca vitripennis. During the growing season, rates of X. fastidiosa spread in vineyards are affected by changes in pathogen distribution within chronically infected grapevines and by vector population dynamics. Grapevines chronically infected with X. fastidiosa rarely tested positive for the pathogen prior to July, suggesting vector acquisition of X. fastidiosa from grapevines increases as the season progresses. This hypothesis was supported by an increase in number of X. fastidiosa-positive glassy-winged sharpshooters collected from vineyards during July through September. Analysis of insecticide records indicated that vineyards in the study area were typically treated with a systemic neonicotinoid in spring of each year. As a result, abundance of glassy-winged sharpshooters was typically low in late spring and early summer, with abundance of glassy-winged sharpshooter adults increasing in late June and early July of each year. Collectively, the results suggest that late summer is a crucial time for X. fastidiosa secondary spread in vineyards in the southern San Joaquin Valley, because glassy-winged sharpshooter abundance, number of glassy-winged sharpshooters testing positive for X. fastidiosa, and grapevines with detectable pathogen populations were all greatest during this period.

Changes in climate patterns are dramatically influencing some agricultural areas. Arid, semi‐arid and coastal agricultural areas are especially vulnerable to climate change impacts on soil salinity. Inventorying and monitoring climate change impacts on salinity are crucial to evaluate the extent of the problem, to recognize trends and to formulate irrigation and crop management strategies that will maintain the agricultural productivity of these areas. Over the past three decades, Corwin and colleagues at the U.S. Salinity Laboratory (USSL) have developed proximal sensor and remote imagery methodologies for assessing soil salinity at multiple scales. The objective of this paper is to evaluate the impact climate change has had on selected agricultural areas experiencing weather pattern changes, with a focus on the use of proximal and satellite sensors to assess salinity development. Evidence presented in case studies for Californiaʼs San Joaquin Valley (SJV) and Minnesotaʼs Red River Valley (RRV) demonstrates the utility of these sensor approaches in assessing soil salinity changes due to changes in weather patterns. Agricultural areas are discussed where changes in weather patterns have increased root‐zone soil salinity, particularly in areas with shallow water tables (SJV and RRV), coastal areas with seawater intrusion (e.g., Bangladesh and the Gaza Strip) and water‐scarce areas potentially relying on degraded groundwater as an irrigation source (SJV and Murray‐Darling River Basin). Trends in salinization due to climate change indicate that the infrastructure and protocols to monitor soil salinity from field to regional to national to global scales are needed. HIGHLIGHTS: Climate change will have a negative impact on agriculture, particularly in arid regions. Proximal/remote sensors are useful to assess climate change impact on soil salinity across scales. Salt‐water intrusion, shallow water tables and degraded water reuse will increase soil salinity. Infrastructure and protocols to monitor soil salinity across multiple scales are needed.

For many agricultural systems, limited data is available on abundance and diversity of insects that are not crop pests or their natural enemies. As recent studies suggest that insect abundance and diversity is declining, there is a need to quantify insect diversity within crop fields to determine what role crop fields play in maintaining diversity. In this study, alfalfa fields, almond orchards, vineyards, olive orchards, and pastures located in the San Joaquin Valley of California were sampled. Ground sweep samples were collected from all five habitats. In addition, foliar beat samples were collected from almond orchards, vineyards, and olive orchards. In total, ~ 240,000 arthropods were collected with the majority identified to family. Across crops and sampling methods, 20 arthropod orders and 202 insect families were observed. Hemiptera was the most abundant order of insect collected, representing an average of 61% of all arthropods collected. Diptera was the most diverse order of insect collected, with a total of 59 dipteran families observed across crops. Of the 202 insect families observed, 85 were observed in all 5 habitats (42%), whereas 48 families were observed in only one habitat (24%). Families observed in a single habitat were often represented by only a few individuals. Principal component analysis indicated that the communities present in the understory of vine and tree crops were more similar to each other than to the communities observed in pastures or alfalfa fields. Much of the total insect biomass belonged to a few families that included known agricultural pests. In contrast, most of the diversity was made up of families present in low to moderate abundance.

California pistachio growers have traditionally grown only one female cultivar (‘Kerman’) and one male pollenizer (‘Peters’). Starting in 2005, the UC breeding program released several improved cultivars, which are being planted on increasing acreage — and tested now under commercial conditions at multiple sites over multiple years. We conducted six experimental trials in the San Joaquin Valley to evaluate the performance of the UC cultivars ‘Gumdrop’, ‘Golden Hills’ and ‘Lost Hills’ and their associated UC male pollenizers ‘Famoso’, ‘Randy’ and ‘Tejon’ against the performance of the traditional pair, ‘Kerman’ and ‘Peters’. The new cultivars demonstrated a range of earlier bloom and harvest dates than ‘Kerman’ and some improved nut quality characteristics, such as a higher percentage of split, in-shell nuts. Results indicate that by growing the new female cultivars and synchronous pollenizers, producers can avoid the peak harvest period for ‘Kerman’, when equipment and processing facilities are limited, and maintain or improve their yield and nut quality.

Purpose ”“ In the current development of Chilean society there is a profound socio-demographic transformation, which implies an advanced aging of the population. Methodology ”“ According to the 2017 Census, 17.7 percent - equivalent to 1,586,634 women - are 60 years of age or older, while men in the same age group account for 14.7 percent (1,263,537). This age group constitutes an enormous challenge for the design of public policies. Findings ”“ It is necessary to generate access policies that take into account the different educational levels of older people in order to overcome the digital divide, as well as incentives for skills and competencies in the various uses and benefits currently provided by ICTs.

Land subsidence is effecting several metropolis in the developing as well as developed countries around the world such as Nagoya (Japan), Shanghai (China), Venice (Italy) and San Joaquin valley (United States). This phenomenon is attributed to natural as well as anthropogenic activities that include extensive groundwater withdrawals. Quetta which is facing similar subsidence phenomenon is the largest city of Balochistan province in Pakistan. This valley is mostly dry and ground water is the major source for domestic and agricultural consumption. The unplanned use of ground water resources has led to the deterioration of water quality and quantity in the Quetta valley. Water shortages in the region was further aggravated by the drought during (1998–2004) that affected the area forcing people to migrate from rural to urban areas. Refugees from the war torn neighboring Afghanistan also contributed to rapid increase in population of Quetta valley that has increased from 0.26 million in 1975 to 3.0 million in 2016. The objective of this study was to measure the land subsidence in Quetta valley and identify the effects of groundwater withdrawals on land subsidence. To achieve this goal, data from five Global Positioning System (GPS) stations in Quetta were acquired and processed. Furthermore the groundwater decline data from 41 observation wells during 2010 to 2015 were calculated and compared with the land deformation. The results of the GPS readings revealed that the land of Quetta valley is subsiding from 30 mm yr−1 on the flanks to 120 mm yr−1 in the central part. 1.5–5.0 m yr−1 of groundwater level drop was recorded in the area where the rate of subsidence is highest. Whereas 9–10 cm of subsidence was recorded in the surrounding areas of Quetta where agriculture and settlements are high. The surrounding areas include Kuchlak, Mastung, Pishin, Gulistan and Hurumzai districts. These results were acquired using InSAR imagery collected from October 2014 to march 2019. So the extensive groundwater withdrawals in Quetta valley and surrounding areas is considered to be the driving force behind land subsidence.

This article examines how clean air advocates in the San Joaquin Valley amplified a collective action frame of air pollution as a public health crisis. This frame serves to mobilize communities and attribute responsibility to relevant authorities while countering the San Joaquin Valley Air District’s narrative that places blame on the public and unalterable aspects of the physical environment, characterizing the problem as largely unchangeable. Core questions are: How did advocates facilitate frame construction and sustain resonance across time and place? How did this frame compel urgent action, including representational change in the Valley Air District Governing Board through the adoption of Senate Bill 719? Findings show that advocates counter the San Joaquin Valley Air District’s frame by shifting the focus on the negative impacts to public health and quality of life, particularly in disproportionately impacted environmental justice communities. Building and leveraging a resonant frame required strategic “stretch” in capacity while cultivating collective identity and solidarity. Within the Valley Air District, the change in governing board composition has measurably impacted dialog and provided a more welcoming reception of public participation at meetings, with the doctor and scientist appointees providing critical perspectives and contributing to subtle shifts in the agency’s dominant messaging and decision making. While a public health frame has taken shape around air pollution in the San Joaquin Valley, these efforts are not complete or without ongoing strain.

Severe effects of selenium (Se) occurred among birds feeding and nesting at Kesterson Reservoir (San Joaquin Valley, California, USA) in 1983 to 1985. This paper describes the integration of site monitoring, risk assessment, and management actions conducted after the effects of Se were discovered. Selenium contamination of the site occurred over just a few years, but actions to resolve the contamination issues required >20 y. The reservoir, a series of 12 ponds totaling about 1280 acres (518 hectares), served for storage and evaporation of subsurface agricultural drainage. Selenium concentrations in reservoir inflow in 1983 were about 300 µg/L, primarily as selenate; within the ponds it was biogeochemically reduced to other inorganic and organic forms and bioaccumulated by biota or deposited to sediments. An estimated 9000 kg of Se were delivered to Kesterson in 1981-1986. A 1985 order required cleanup and abatement of the reservoir, so the United States Bureau of Reclamation and the US Department of the Interior undertook actions and studies to reduce hazards to birds. In 1988, about 1 million cubic yards (764 500 m3 ) of soil were used to fill portions of the reservoir, transforming it into terrestrial habitat. Intensive monitoring began in 1989 to assess the impact of the reservoir on wildlife, provide a basis for adjusting site management, verify the effectiveness of cleanup actions, and provide a basis for modifying future monitoring. Monitoring continued until 2014, with modifications and management actions based on results of 2 risk assessments (1993 and 2000). Monitoring results in 2013-2014 showed that Se concentrations were relatively stable over time and risks to wildlife were low. From the initial problem discovery to the conclusion of actions taken to remediate the site, combining responsive, reactive, and adaptive monitoring; modeling; risk assessment; and mitigation actions proved effective in solving the problem so that risks to wildlife were reduced to minimal levels. Integr Environ Assess Manag 2020;16:257-268. © 2019 SETAC.

California produces over 95% of the olives grown in the United States. In 2017, California’s total bearing acreage for olives was 14,570 hectares producing 192,000 tons of olives valued at $186.6 million. During the early spring of 2016, unusual leaf and shoot lesions were detected in olive trees from superhigh-density orchards in the Northern San Joaquin and Sacramento valleys of California. Affected trees displayed numerous leaf and shoot lesions developing at wounds created by mechanical harvesters. The ‘Arbosana’ cultivar was highly affected by the disease, whereas the disease was sporadic in ‘Arbequina’ and not found in ‘Koroneiki’ cultivar. Two fungal species, Neofabraea kienholzii and Phlyctema vagabunda, were found to be consistently associated with the disease, and Koch’s postulates were completed. Species identity was confirmed by morphology and molecular data of the partial large subunit rDNA, the internal transcribed spacer region, and partial beta-tubulin region. The disease signs and symptoms are described and illustrated.

Plug-in electric Vehicles (PEVs) are believed to be one of the solutions to mitigate emissions from road transportation. Which types of factors are most effective at encouraging PEV adoption, and what magnitude of reduction in emissions could be achieved by expanding charging infrastructure as an influential factor on PEVs? To answer these questions, we developed a statistical model relating charging station infrastructure and other potential factors to PEV adoption rate in 58 California counties. We found that male buyers in households with fewer number of vehicles are more likely to purchase PEVs particularly in counties with more available public charging station per capita. Then we investigated the life-cycle petroleum use, emissions, and costs of light duty vehicles for a hypothetical scenario where existing public charging stations are expanded relative to total daily miles travelled in each county. We found under this scenario Modoc County experiences the largest reduction in life-cycle GHG emissions, by 0.035%, followed by Sierra and Mono counties. The smallest potential is found in counties with low response rate to expanded charging station infrastructure, led by Alpine, Del Norte, and King counties. For 20 counties, including Butte, San Joaquin, and San Francisco, the benefit-cost ratio is less than one, which means the investment and maintenance costs of new infrastructure have not been offset by operation and externality cost savings. For the rest of the counties, this scenario is found to be compatible. The results assist planners in assessing environmental and economic benefits of PEVs and optimizing infrastructural investments.

Thermal infrared spectra can provide unique information on atmospheric ammonia enhancements, including those produced by agricultural, industrial, and biomass burning sources. In this work, we develop and test a quantitative ammonia retrieval algorithm using data from the airborne hyperspectral thermal emission spectrometer (HyTES) instrument over diverse targets, including persistent ammonia sources, such as cattle feedlots and a power plant, as well as a small, smoldering wildfire. Although no formal validation was possible due to lack of collocated observations, the HyTES ammonia values over feedlots in the California San Joaquin Valley are shown to be consistent within the estimated retrieval uncertainty of $\sim$ 20%–50% with in situ ammonia values collected over the same facilities during the 2013 DISCOVER-AQ field campaign. HyTES also observed meter-scale thermal hot spots associated with a small wildfire in Northern Arizona, which was determined to coincide with the emission of free ammonia, presumed to originate from the fire. This very localized emission source, not visible from satellite sensors, could be resolved in HyTES imagery. The ammonia enhancement immediately downwind from the smoldering fire, before the free ammonia reacted to form aerosols, was found to be distinguishable from the background with values three to ten times smaller than ammonia enhancements from the power plant and cattle feedlots, respectively. High-resolution detection and quantification of ammonia over nonpersistent sources like wildfires from HyTES shows that it is a powerful tool that can be used to improve regional scale fire emission inventories by accounting for the presence of temporally short ammonia processes.

Environmental and socioeconomic risk factors associated with the incidence of human West Nile virus (WNV) cases were investigated in the Northern San Joaquin Valley region of California, a largely rural area. The study included human WNV cases from the years 2011 to 2015 in the three-county area of San Joaquin, Stanislaus, and Merced Counties, and used census tracts as the unit of analysis. Environmental factors included temperature, precipitation, and WNV-positive mosquito pools. Socioeconomic variables included age, housing age, housing foreclosures, median income, and ethnicity. Chi-square independence tests were used to examine whether each variable was associated with the incidence of WNV cases using data from the three counties combined. In addition, negative binomial regression revealed that the environmental factors of temperature and precipitation were the strongest predictors of the incidence of human WNV cases, while the socioeconomic factor of ethnicity was a significant predictor as well, and is a factor to consider in prevention efforts. Source reduction of mosquito breeding sites and targeted prevention and education remain key in reducing the risk associated with WNV.