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Geology and hydrogeology of the Yucaipa groundwater subbasin, San Bernardino and Riverside Counties, California

The Yucaipa groundwater subbasin (referred to in this report as the Yucaipa subbasin) is located about 75 miles (mi) east of of Los Angeles and about 12 mi southeast of the City of San Bernardino. In the Yucaipa subbasin, as in much of southern California, limited annual rainfall and large water demands can strain existing water supplies; therefore, understanding local surface water and groundwate

Use case development for earth monitoring, analysis, and prediction (EarthMAP)—A road map for future integrated predictive science at the U.S. Geological Survey

Executive SummaryThe U.S. Geological Survey (USGS) 21st-century science strategy 2020–30 promotes a bureau-wide strategy to develop and deliver an integrated, predictive science capability that works at the scales and timelines needed to inform societally relevant resource management and protection and public safety and environmental health decisions (U.S. Geological Survey, 2021). This is the ove

Climate and land change impacts on future managed wetland habitat: A case study from California’s Central Valley

ConceptCalifornia’s Central Valley provides critical habitat for migratory waterbirds, yet only 10% of naturally occurring wetlands remain. Competition for limited water supplies and climate change will impact the long-term viability of these intensively managed habitats.ObjectivesForecast the distribution, abundance, and connectivity of surface water and managed wetland habitats, using 5 spatiall

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

Improving groundwater model calibration with repeat microgravity measurements

Groundwater-flow models depend on hydraulic head and flux observations for evaluation and calibration. A different type of observation—change in storage measured using repeat microgravity—can also be used for parameter estimation by simulating the expected change in gravity from a groundwater model and including the observation misfit in the objective function. The method is demonstrated using new

Juvenile African clawed frogs (Xenopus laevis) express growth, metamorphosis, mortality, gene expression, and metabolic changes when exposed to thiamethoxam and clothianidin

Neonicotinoids (NEO) represent the main class of insecticides currently in use, with thiamethoxam (THX) and clothianidin (CLO) primarily applied agriculturally. With few comprehensive studies having been performed with non-target amphibians, the aim was to investigate potential biomarker responses along an adverse outcome pathway of NEO exposure, whereby data were collected on multiple biological

Geostatistical mapping of salinity conditioned on borehole logs, Montebello Oil Field, California

We present a geostatistics-based stochastic salinity estimation framework for the Montebello Oil Field that capitalizes on available total dissolved solids (TDS) data from groundwater samples as well as electrical resistivity (ER) data from borehole logging. Data from TDS samples (n = 4924) was coded into an indicator framework based on falling below four selected thresholds (500, 1000, 3000, and

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 habita

The silence of the clams: Forestry registered pesticides as multiple stressors on soft-shell clams

Contaminants are ubiquitous in the environment, often reaching aquatic systems. Combinations of forestry use pesticides have been detected in both water and aquatic organism tissue samples in coastal systems. Yet, most toxicological studies focus on the effects of these pesticides individually, at high doses, and over acute time periods, which, while key for establishing toxicity and safe limits,

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

Synthesis of data and studies relating to Delta Smelt biology in the San Francisco Estuary, emphasizing water year 2017

In the San Francisco Estuary (SFE), the effects of freshwater flow on the aquatic ecosystem have been studied extensively over the years and remains a contentious management issue. It is especially contentious with regards to the Delta Smelt (Hypomesus transpacificus), a species endemic to the SFE that has been listed as threatened under the Federal Endangered Species Act and endangered by the Sta

Detection and measurement of land-surface deformation, Pajaro Valley, Santa Cruz and Monterey counties, California, 2015–18

Land-surface deformation (subsidence) caused by groundwater withdrawal is identified as an undesirable result in the Pajaro Valley Water Management Agency’s Basin Management Plan and California’s Sustainable Groundwater Management Act. In Pajaro Valley, groundwater provides nearly 90 percent of the total water supply. To aid the development of sustainable groundwater management criteria, the U.S.