Publications

With the goal of improving property-transfer model (PTM) predictions of unsaturated hydraulic properties, we investigated the influence of sedimentary structure, defined as particle arrangement during deposition, on laboratory-measured water retention (water content vs. potential [θ(ψ)]) of 10 undisturbed core samples from alluvial deposits in the western Mojave Desert, California. The...

Twenty-eight sites along the Wasatch Front, north central Utah, representing the range ot urban land use intensity for wadeable streams of the area, were sampled in September 2000. Fish communities were assessed by single-pass electrofishing, and physical habitat and water-quality characteristics were measured. On average, nonnative species comprised 54% of species richness and 53% of...

Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may...

Although surface water quality and its underlying processes vary over time scales ranging from seconds to decades, they have historically been studied at the lower (weekly to interannual) frequencies. The aim of this study was to investigate intradaily variability of three water quality parameters in a small freshwater tidal lagoon (Mildred Island, California). High frequency time series...

Climate variations can play an important, if not always crucial, role in successful conjunctive management of ground water and surface water resources. This will require accurate accounting of the links between variations in climate, recharge, and withdrawal from the resource systems, accurate projection or predictions of the climate variations, and accurate simulation of the responses...

Water-resources data for the 2004 water year for California consist of records of stage, discharge, and water quality of streams, stage and contents in lakes and reservoirs, and water levels and water quality in wells. Volume 1 contains discharge records for 195 gaging stations and 10 crest-stage partial-record stations, stage and contents for 25 lakes and reservoirs, gage-height records...

The uncertainties associated with climate-change projections for California are unlikely to disappear any time soon, and yet important long-term decisions will be needed to accommodate those potential changes. Projection uncertainties have typically been addressed by analysis of a few scenarios, chosen based on availability or to capture the extreme cases among available projections...

In this paper, we review information regarding the status of the native fishes of the combined Sacramento River and San Joaquin River drainages (hereinafter the "Sacramento-San Joaquin drainage") and the factors associated with their declines. The Sacramento-San Joaquin drainage is the center of fish evolution in California, giving rise to 17 endemic species of a total native fish fauna...

Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem...

Cross‐stream velocity was measured in a large river bend at high spatial resolution over three separate survey episodes. A suite of methods for resolving cross‐stream velocity distributions was tested on data collected using acoustic Doppler current profilers (ADCP) in the sand‐bedded Sacramento River, California. The bend was surveyed with repeated ADCP crossings at eight cross sections...

We assessed the structure of periphyton, benthic macroinvertebrate, and fish assemblages and their associations with environmental variables at 17 sites on streams of the highly urbanized Santa Ana River basin in Southern California. All assemblages exhibited strong differences between highly urbanized sites in the valley and the least-impacted sites at the transition between the valley...

Chloride concentrations were as high as 230 mg/L in water from the surface discharge of long-screened production wells in Pleasant Valley, Calif., about 100 km NW of Los Angeles. Wells with the higher Cl− concentrations were near faults that bound the valley. Depending on well construction, high-Cl−water from different sources may enter a well at different depths. For example, Cl−...