SEARCH · USGS Science

Results for “Water Resources Impact”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources

USGS2022

Functional wetland loss drives emerging risks to waterbird migration networks

Migratory waterbirds (i.e., shorebirds, wading birds, and waterfowl) rely on a diffuse continental network of wetland habitats to support annual life cycle needs. Emerging threats of climate and land-use change raise new concerns over the sustainability of these habitat networks as water scarcity triggers cascading ecological effects impacting wetland habitat availability. Here we use important waterbird regions in Oregon and California, United States, as a model system to examine patterns of landscape change impacting wetland habitat networks in western North America. Wetland hydrology and flooded agricultural habitats were monitored monthly from 1988 to 2020 using satellite imagery to quantify the timing and duration of inundation—a key delimiter of habitat niche values associated with waterbird use. Trends were binned by management practice and wetland hydroperiods (semi-permanent, seasonal, and temporary) to identify differences in their climate and land-use change sensitivity. Wetland results were assessed using 33 waterbird species to detect non-linear effects of network change across a diversity of life cycle and habitat needs. Pervasive loss of semi-permanent wetlands was an indicator of systemic functional decline. Shortened hydroperiods caused by excessive drying transitioned semi-permanent wetlands to seasonal and temporary hydrologies—a process that in part counterbalanced concurrent seasonal and temporary wetland losses. Expansion of seasonal and temporary wetlands associated with closed-basin lakes offset wetland declines on other public and private lands, including wildlife refuges. Diving ducks, black terns, and grebes exhibited the most significant risk of habitat decline due to semi-permanent wetland loss that overlapped important migration, breeding, molting, and wintering periods. Shorebirds and dabbling ducks were beneficiaries of stable agricultural practices and top-down processes of functional wetland declines that operated collectively to maintain habitat needs. Outcomes from this work provide a novel perspective of wetland ecosystem change affecting waterbirds and their migration networks. Understanding the complexity of these relationships will become increasingly important as water scarcity continues to restructure the timing and availability of wetland resources.

California, Nevada, Oregon↗

USGS2025

Linking fire, food webs, and fish in stream ecosystems

As wildfire regimes shift, resource managers are concerned about potential threats to aquatic ecosystems and the species they support, especially fishes. However, predicting fish responses can be challenging because wildfires affect aquatic ecosystems via multiple pathways. Application of whole-ecosystem approaches, such as food web modeling, can act as heuristic tools that offer valuable insights that account for these different mechanisms. We applied a dynamic food web simulation model that mechanistically linked stream trophic dynamics to the myriad effects that wildfires can have on aquatic and riparian ecosystems at a local stream reach-scale. We simulated how wildfires of different severity may influence short- (months to years) and long-term (years to decades) periphyton, aquatic invertebrate, and fish biomass dynamics in forested headwater streams of the western Pacific Northwest (USA). In many cases, wildfire increased modeled periphyton, invertebrate, and fish biomass over both short- and long-time periods. However, modeled responses varied extensively in their direction (that is, positive or negative), magnitude, and duration depending on fire severity, time since fire, and trophic level. The shapes of these response trajectories were especially sensitive to predicted wildfire effects on water temperature, canopy cover, riparian shading, and instream turbidity. Model simulations suggest a single fire could result in a wide range of aquatic ecosystem responses, especially in watersheds with mixed burn severity. Our analysis highlights the utility of whole-ecosystem approaches, like food web modeling, as heuristic tools for improving our understanding of the mechanisms linking fire, food webs, and fish and for identifying contexts where fires could have deleterious impacts on fishes.

Oregon, Washington↗

USGS2001

Sedimentation survey of Lago Caonillas, Puerto Rico, February 2000

Lago Caonillas, a reservoir owned by the Puerto Rico Electric Power Authority and located in the central part of Puerto Rico, is one of the two reservoirs (the other being Lago Dos Bocas) proposed to supply water for the Puerto Rico Aqueduct and Sewer Authority project called the Superaqueduct. The reservoir was impounded in 1948 and originally provided about 55 .66 million cubic meters of water for hydroelectric power generation. Sediment derived from the reservoir basin has been transported and deposited in the reservoir bottom, substantially decreasing the water storage capacity over time. Successive bathymetric surveys indicated that in 1990 the storage capacity was 49.25 million cubic meters, decreasing to 48.80 million cubic meters in 1995 and to 42.27 million cubic meters in 2000. This represents an overall storage loss of about 11.5 percent by 1990, 12.3 percent by 1995 and 24.1 percent by 2000. The long-term sedimentation rate of the reservoir was about 153,000 cubic meters per year in 1990, remaining almost constant at about 146,000 cubic meters per year in 1995, but nearly doubling to 258,000 cubic meters per year in 2000. The two-fold increase in sedimentation rate, and consequently, the reservoir storage capacity loss, can be attributed to Hurricane Hortense in September 1996 and Hurricane Georges in September 1998. Twenty-four percent of the original storage capacity of Lago Caonillas has been lost to sediment accumulation. About 49 percent of the reservoir sediment was deposited in the last five years, demonstrating the impact of these major storms on the reservoir. Based on the ratio of storage capacity to inflow rate, the estimated trapping efficiency of Lago Caonillas is about 93 percent for 2000. The sediment yield of the Lago Caonillas net sediment-contributing drainage area (total drainage area minus the reservoir surface area) of 218.74 square kilometers, is about 1 ,266 megagrams per square kilometer per year. This represents an increase of about 69 percent in the material transport and deposition process of the Lago Caonillas basin between 1990 and 2000. The life expectancy of Lago Caonillas was more than 300 years in 1995; however, at the storm-accelerated sedimentation rate, the life expectancy has decreased to about 164 years. This implies that the reservoir could be filled with sediments by the year 2164 if major hurricanes continue to pass through Puerto Rico regularly (every 2 to 4 years).

Puerto Rico↗

USGS1996

Use of a ground-water flow model with particle tracking to evaluate ground-water vulnerability, Clark County, Washington

A ground-water flow model was used in conjunction with particle tracking to evaluate ground-water vulnerability in Clark County, Washington. Using the particle-tracking program, particles were placed in every cell of the flow model (about 60,000 particles) and tracked backwards in time and space upgradient along flow paths to their recharge points. A new computer program was developed that interfaces the results from a particle-tracking program with a geographic information system (GIS). The GIS was used to display and analyze the particle-tracking results. Ground-water vulnerability was evaluated by selecting parts of the ground-water flow system and combining the results with ancillary information stored in the GIS to determine recharge areas, characteristics of recharge areas, downgradient impact of land use at recharge areas, and age of ground water. Maps of the recharge areas for each hydrogeologic unit illustrate the presence of local, intermediate, or regional ground-water flow systems and emphasize the three-dimensional nature of the ground-water flow system in Clark County. Maps of the recharge points for each hydrogeologic unit were overlaid with maps depicting aquifer sensitivity as determined by DRASTIC (a measure of the pollution potential of ground water, based on the intrinsic characteristics of the near-surface unsaturated and saturated zones) and recharge from on-site waste-disposal systems. A large number of recharge areas were identified, particularly in southern Clark County, that have a high aquifer sensitivity, coincide with areas of recharge from on-site waste-disposal systems, or both. Using the GIS, the characteristics of the recharge areas were related to the downgradient parts of the ground-water system that will eventually receive flow that has recharged through these areas. The aquifer sensitivity, as indicated by DRASTIC, of the recharge areas for downgradient parts of the flow system was mapped for each hydrogeologic unit. A number of public-supply wells in Clark County may be receiving a component of water that recharged in areas that are more conducive to contaminant entry. The aquifer sensitivity maps illustrate a critical deficiency in the DRASTIC methodology: the failure to account for the dynamics of the ground-water flow system. DRASTIC indices calculated for a particular location thus do not necessarily reflect the conditions of the ground-water resources at the recharge areas to that particular location. Each hydrogeologic unit was also mapped to highlight those areas that will eventually receive flow from recharge areas with on-site waste-disposal systems. Most public-supply wells in southern Clark County may eventually receive a component of water that was recharged from on-site waste-disposal systems.Traveltimes from particle tracking were used to estimate the minimum and maximum age of ground water within each model-grid cell. Chlorofluorocarbon (CFC)-age dating of ground water from 51 wells was used to calibrate effective porosity values used for the particle- tracking program by comparison of ground-water ages determined through the use of the CFC-age dating with those calculated by the particle- tracking program. There was a 76 percent agreement in predicting the presence of modern water in the 51 wells as determined using CFCs and calculated by the particle-tracking program. Maps showing the age of ground water were prepared for all the hydrogeologic units. Areas with the youngest ground-water ages are expected to be at greatest risk for contamination from anthropogenic sources. Comparison of these maps with maps of public- supply wells in Clark County indicates that most of these wells may withdraw ground water that is, in part, less than 100 years old, and in many instances less than 10 years old. Results of the analysis showed that a single particle-tracking analysis simulating advective transport can be used to evaluate ground-water vulnerability for any part of a ground-wate

Open-File Report↗

USGS2023

Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2022 Report)

A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to provide the information necessary to overcome those challenges (e.g., Plant Conservation Alliance, 2015; Breed et al., 2018; Winkler et al., 2018; NASEM, 2023). Many of the most complex information needs relate to identifying the appropriate sources of plant species that can successfully establish in dryland environments, like the Colorado Plateau, where low and highly variable precipitation is standard. Providing this information requires synergistic research efforts in which results from earlier investigations inform the design of subsequent investigations. The U.S. Geological Survey (USGS) Southwest Biological Science Center’s (SBSC’s) research activities to support CPNPP in FY22 followed the FY22 Statement of Work to support a research framework that is continually adapting based on the needs of the restoration community and results from previous investigations; the long-term research framework is outlined in the 2019-2023 5-Year Research Strategy (hereafter referred to as the 5-year plan). This research framework provides support for the National Seed Strategy for Rehabilitation and Restoration (Plant Conservation Alliance, 2015), Biden-Harris Administration Executive Order 14008 (Tackling the Climate Crisis at Home and Abroad), and Department of Interior Priority #4 (Working to conserve at least 30% each of our lands and waters by the year 2030). Research activities in FY22 centered on landscape genomics, monitoring common garden and seeding experiments near Vernal and Moab, UT, conducting experimental treatments using the GRID (Germination for Restoration Information and Decision-making) framework, and continuing newer genetics projects to investigate the impact of productions techniques on plant materials and restoration treatments on native plant communities. These activities were supported by two biological science technicians. The effects of the SARS-CoV-2 pandemic were less visible in FY22, allowing SBSC to catch up on backlogged laboratory work. The overall progress of SBSC’s research remains on track with respect to the 5-year plan. While Dr. Rob Massatti was the only scientist supported by the SBSC-CPNPP agreement in FY22, other scientists, including Drs. John Bradford, Seth Munson, Mike Duniway, Sasha Reed, and Daniel Winkler, spent a considerable amount of time providing expertise and support for individual projects. Work activities performed in support of each 5-year plan goal are discussed in turn.

Colorado Plateau↗

USGS2011

Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon

Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high‐flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris . Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa ( P. antipodarum , G. lacustris , and Tubificida). In contrast to invertebrates, production of rainbow trout ( Oncorhynchus mykiss ) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post‐flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer–resource interactions were not necessarily congruent with the dominant organic matter flows. Our study illustrates the value of detailed food web analysis for elucidating pathways by which dam management may alter production and strengths of species interactions in river food webs. We suggest that controlled floods may increase production of nonnative rainbow trout, and this information can be used to help guide future dam management decisions.

Arizona↗

USGS2022

Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2021 Report)

A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to provide the information necessary to overcome those challenges (e.g., Plant Conservation Alliance 2015; Breed et al. 2018; Winkler et al. 2018; McCormick et al. 2021). Many of the most complex information needs relate to identifying the appropriate sources of plant species that can successfully establish in dryland environments, like the Colorado Plateau, where low and highly variable precipitation is standard. Providing this information requires synergistic research efforts in which results from earlier investigations inform the design of subsequent investigations. The U.S. Geological Survey (USGS) Southwest Biological Science Center’s (SBSC’s) research activities to support CPNPP in FY21 followed the FY21 Statement of Work to support a research framework that is continually adapting based on the needs of the restoration community and results from previous investigations; the long-term research framework is outlined in the 2019-2023 5-Year Research Strategy (hereafter referred to as the 5-year plan). This research framework provides support for the National Seed Strategy for Rehabilitation and Restoration (Plant Conservation Alliance 2015), Biden-Harris Administration Executive Order 14008 (Tackling the Climate Crisis at Home and Abroad), and Department of Interior Priority #4 (Working to conserve at least 30% each of our lands and waters by the year 2030). Research activities in FY21 centered on landscape genomics, implementing and monitoring a common garden experiment near Vernal, UT, conducting experimental treatments using the GRID (Germination for Restoration Information and Decision-making) framework, and initiating new genetics projects to investigate the impact of production techniques on plant materials and restoration treatments on native plant communities. These activities were supported by four biological science technicians. The SARS-CoV-2 pandemic delayed some aspects of the FY21 workplan, especially for outside laboratory services. However, goals were largely met, and the overall progress of research remains on track with respect to the 5-year plan. While Dr. Rob Massatti was the only scientist supported by the SBSC-CPNPP agreement in FY21, other scientists, including Drs. John Bradford, Seth Munson, Mike Duniway, Sasha Reed, and Daniel Winkler, spent a considerable amount of time providing expertise and support for individual projects. Work activities performed in support of each 5-year plan goal are discussed in turn. Products resulting from FY21 research activities are reported in Appendix 1.

Arizona, Colorado, New Mexico, Utah↗

USGS1990

Monitoring long-term effects of offshore oil and gas development along the Southern California outer continental shelf and slope: Background environmental conditions in the Santa Maria Basin

Potential environmental impacts of materials discharged from oil and gas development and production platforms off the coast of southern California (Santa Maria Basin) are being monitored during an ongoing, long-term (fiveyear) field program. The study combines hypothesis testing of platform effects with basic research on the structure and dynamics of the regional ecosystem over a time series encompassing both seasonal and repeated annual scales. Oceanographic features and processes that are being measured focus on the benthos and include biological community indices and species abundances for hard-bottom and soft-bottom (macroinfauna and meiofauna) assemblages; levels and distributions of trace metals and hydrocarbons in bottom sediments, suspended particulates, animal tissues, and pore waters; water currents and otherphysical-oceanographicfeatures; various sedimentological properties (sediment grain size, total organic carbon, shear strength, distribution of mineral types, radioisotope profiles, and degrees of sediment mixing as a result of bioturbation); sediment and pollutant-transport processes; and animal-sediment-pollutant interactions. Synoptic measurement of these different environmental variables over the extended sampling period provides an opportunity to examine long-term variability in the benthic environment with respect to both natural and anthropogenic causes. Efforts to distinguish between natural variability and low-level cumulative impacts of drilling are given special attention. Results obtained during the first two years of sampling provide a basis for beginning to understand environmental processes and relations important in detecting and interpreting any subsequent impacts caused by drilling activities in this complex and productive region of the California outer continental shelf and slope. Background chemical, physical, and biological data generated during this period demonstrate that impacts of discharges from oil and gas operations should be detectable, if they occur, and should be distinguishable from natural environmental variability. Small inputs of barium and petroleum hydrocarbons have been detected and appear to be associated with the minor drilling activities that have occurred in the area thus far, however, these initial inputs have not led to any noticeable biological impacts. These initial results are hopefully of value for two reasons: (1) in providing a summary of basic chemical, physical, and biological features of the benthic environment within the Santa Maria Basin; and (2) in presenting information on research strategies that should be considered in designing studies dealing with similar resource-management problems in other parts of the world.

California↗

USGS2011

Shallow stratigraphy of the Skagit River Delta, Washington, derived from sediment cores

Sedimentologic analyses of 21 sediment cores, ranging from 0.4 to 9.6 m in length, reveal that the shallow geologic framework of the Skagit River Delta, western Washington, United States, has changed significantly since 1850. The cores collected from elevations of 3.94 to -2.41 m (relative to mean lower low water) along four cross-shore transects between the emergent marsh and delta front show relatively similar environmental changes across an area spanning ~75 km 2 . Offshore of the present North Fork Skagit River and South Fork Skagit River mouths where river discharge is focused by diked channels through the delta, the entire 5–7-km-wide tidal flats are covered with 1–2 m of cross-bedded medium-to-coarse sands. The bottoms of cores, collected in these areas are composed of mud. A sharp transition from mud to a cross-bedded sand unit indicates that the tidal flats changed abruptly from a calm environment to an energetic one. This is in stark contrast to the Martha's Bay tidal flats north of the Skagit Bay jetty that was completed in the 1940s to protect the newly constructed Swinomish Channel from flooding and sedimentation. North of the jetty, mud ranging from 1 to 2 m thick drapes a previously silt- and sand-rich tidal flat. The silty sand is a sediment facies that would be expected there where North Fork Skagit River sedimentation occurred prior to jetty emplacement. This report describes the compositional and textural properties of the sediment cores by using geophysical, photographic, x-radiography, and standard sediment grain-size and carbon-analytical methods. The findings help to characterize benthic habitat structure and sediment transport processes and the environmental changes that have occurred across the nearshore of the Skagit River Delta. The findings will be useful for quantifying changes to nearshore marine resources, including impacts resulting from diking, river-delta channelization, shoreline development, and natural variations in fluvial-sediment inputs. These results also provide important quantitative data on the amount of sediment delivered to the nearshore from the Skagit River for use in calculating sediment budgets for application to watershed planning and wetland and coastal-ecosystem restoration.

Washington↗

USGS2022

Water storage decisions and consumptive use may constrain ecosystem management under severe sustained drought

Drought has impacted the Colorado River basin for the past 20 years and is predicted to continue. In response, decisions about how much water should be stored in large reservoirs and how much water can be consumptively used will be necessary. These decisions have the potential to limit riverine ecosystem management options through the effect water-supply decisions have on reservoir elevations. We used projected hydrology and river temperatures to compare the outcome of combinations of water storage scenarios and consumptive use limits on metrics associated with ecosystem management of the Colorado River in Grand Canyon. Ecosystem management metrics included the ability to implement designer flows, temperature suitability for fishes, and fragmentation. We compared current water management operations to prioritizing storage in either Lake Mead or Lake Powell combined with three levels of consumptive use. Projected reservoir levels limited environmental flow delivery and increased fragmentation regardless of where water was stored if consumptive use was not limited. Warmer river temperatures associated with low reservoir levels are likely, creating suitable conditions for non-native species of concern, such as smallmouth bass. Water storage decisions provided variability and management flexibility, but water storage was less important when less water was available, highlighting the importance of keeping water in the system to provide flexibility for achieving ecosystem goals.

Arizona, Utah↗

USGS2017

Complex networks of functional connectivity in a wetland reconnected to its floodplain

Disturbances such as fire or flood, in addition to changing the local magnitude of ecological, hydrological, or biogeochemical processes, can also change their functional connectivity—how those processes interact in space. Complex networks offer promise for quantifying functional connectivity in watersheds. The approach resolves connections between nodes in space based on statistical similarities in perturbation signals (derived from solute time series) and is sensitive to a wider range of timescales than traditional mass-balance modeling. We use this approach to test hypotheses about how fire and flood impact ecological and biogeochemical dynamics in a wetland (Everglades, FL, USA) that was reconnected to its floodplain. Reintroduction of flow pulses after decades of separation by levees fundamentally reconfigured functional connectivity networks. The most pronounced expansion was that of the calcium network, which reflects periphyton dynamics and may represent an indirect influence of elevated nutrients, despite the comparatively smaller observed expansion of phosphorus networks. With respect to several solutes, periphyton acted as a “biotic filter,” shifting perturbations in water-quality signals to different timescales through slow but persistent transformations of the biotic community. The complex-networks approach also revealed portions of the landscape that operate in fundamentally different regimes with respect to dissolved oxygen, separated by a threshold in flow velocity of 1.2 cm/s, and suggested that complete removal of canals may be needed to restore connectivity with respect to biogeochemical processes. Fire reconfigured functional connectivity networks in a manner that reflected localized burn severity, but had a larger effect on the magnitude of solute concentrations.

Florida↗

USGS2017

Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota

Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4 M L (million liters) of wastewater (300 g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemical signatures of spilled wastewaters as well as biological responses along a 44-km river reach. February water samples had elevated chloride (1030 mg/L) and bromide (7.8 mg/L) downstream from the spill, compared to upstream levels (11 mg/L and < 0.4 mg/L, respectively). Lithium (0.25 mg/L), boron (1.75 mg/L) and strontium (7.1 mg/L) were present downstream at 5–10 times upstream concentrations. Light hydrocarbon measurements indicated a persistent thermogenic source of methane in the stream. Semi-volatile hydrocarbons indicative of oil were not detected in filtered samples but low levels, including tetramethylbenzenes and di-methylnaphthalenes, were detected in unfiltered water samples downstream from the spill. Labile sediment-bound barium and strontium concentrations (June 2015) were higher downstream from the Spill Site. Radium activities in sediment downstream from the Spill Site were up to 15 times the upstream activities and, combined with Sr isotope ratios, suggest contributions from the pipeline fluid and support the conclusion that elevated concentrations in Blacktail Creek water are from the leaking pipeline. Results from June 2015 demonstrate the persistence of wastewater effects in Blacktail Creek several months after remediation efforts started. Aquatic health effects were observed in June 2015; fish bioassays showed only 2.5% survival at 7.1 km downstream from the spill compared to 89% at the upstream reference site. Additional potential biological impacts were indicated by estrogenic inhibition in downstream waters. Our findings demonstrate that environmental signatures from wastewater spills are persistent and create the potential for long-term environmental health effects.

North Dakota↗

USGS2018

Hourly analyses of the large storms and atmospheric rivers that provide most of California's precipitation in only 10 to 100 hours per year

California is regularly impacted by floods and droughts, primarily as a result of too many or too few atmospheric rivers (ARs). This study analyzes a two-decade-long hourly precipitation dataset from 176 California weather stations and a 3-hourly AR chronology to report variations in rainfall events across California and their association with ARs. On average, 10-40 and 60-120 hours of rainfall in southern and northern California, respectively, are responsible for more than half of annual rainfall accumulations. Approximately 10-30% of annual precipitation at locations across the state is from only one large storm. On average, northern California receives 25-45 rainfall events annually (40-50% of which are AR-related). These events typically have longer durations and higher event-precipitation totals than those in southern California. Northern California also receives more AR landfalls with longer durations and stronger Integrated Vapor Transport (IVT). On average, ARs contribute 79%, 76%, and 68% of extreme-rainfall accumulations (i.e., top 5% events annually) in the north coast, northern Sierra, and Transverse Ranges of southern California, respectively. The San Francisco Bay Area terrain gap in the California Coast Range allows more AR water vapor to reach inland over the Delta and Sacramento Valley, and thus, influences precipitation in the Delta’s catchment. This is particularly important for extreme precipitation in the northern Sierra Nevada, including river basins above Oroville Dam and Shasta Dam. This study highlights differences between rainfall and AR characteristics in coastal versus inland northern California, differences that largely determine the regional geography of flood risks and water-reliability. These analyses support water resource, flood, levee, wetland, and ecosystem management within the catchment of the San Francisco estuary system by describing regional characteristics of ARs and their influence on rainfall on an hourly timescale.

California↗

USGS1978

Field testing and adaptation of a methodology to measure "in-stream" values in the Tongue River, northern Great Plains (NGP) region

A comprehensive, multi-component in-stream flow methodology was developed and field tested in the Tongue River in southeastern Montana. The methodology incorporates a sensitivity for the flow requirements of a wide variety of in-stream uses, and the flexibility to adjust flows to accommodate seasonal and sub-seasonal changes in the flow requirements for different areas. In addition, the methodology provides the means to accurately determine the magnitude of the water requirement for each in-stream use. The methodology can be a powerful water management tool in that it provides the flexibility and accuracy necessary in water use negotiations and evaluation of trade-offs. In contrast to most traditional methodologies, in-stream flow requirements were determined by additive independent methodologies developed for: 1) fisheries, including spawning, rearing, and food production; 2) sediment transport; 3) the mitigation of adverse impacts of ice; and 4) evapotranspiration losses. Since each flow requirement varied in important throughout the year, the consideration of a single in-stream use as a basis for a flow recommendation is inadequate. The study shows that the base flow requirement for spawning shovelnose sturgeon was 13.0 m 3 /sec. During the same period of the year, the flow required to initiate the scour of sediment from pools is 18.0 m 3 /sec, with increased scour efficiency occurring at flows between 20.0 and 25.0 m 3 /sec. An over-winter flow of 2.83 m 3 /sec. would result in the loss of approximately 80% of the riffle areas to encroachment by surface ice. At the base flow for insect production, approximately 60% of the riffle area is lost to ice. Serious damage to the channel could be incurred from ice jams during the spring break-up period. A flow of 12.0 m 3 /sec. is recommended to alleviate this problem. Extensive ice jams would be expected at the base rearing and food production levels. The base rearing flow may be profoundly influenced by the loss of streamflow to transpiration. Transpiration losses to riparian vegetation ranged from 0.78 m 3 /sec. in April, to 1.54 m 3 /sec. in July, under drought conditions. Requirement for irrigation were estimated to range from 5.56 m 3 /sec. in May to 7.97 m 3 /sec. in July, under drought conditions. It was concluded that flow requirements to satisfy monthly water losses to transpiration must be added to the base fishery flows to provide adequate protection to the resources in the lower reaches of the river. Integration of the in-stream requirements for various use components shows that a base flow of at least 23.6 m 3 /sec. must be reserved during the month of June to initiate scour of sediment from pools, provide spawning habitat to shovelnose sturgeon, and to accommodate water losses from the system. In comparison, a base flow of 3.85 m 3 /sec. would be required during early February to provide fish rearing habitat and insect productivity, and to prevent excessive loss of food production areas to surface ice formation. During mid to late February, a flow of 12 m 3 /sec. would be needed to facilitate ice break-up and prevent ice jams from forming. Following break-up, the base flow would again be 3.85 m 3 /sec. until the start of spawning season.

Northern Great Plains↗

USGS1978

Effects of urban development on the flood-flow characteristics of the Walnut Creek Basin, Des Moines Metropolitan area, Iowa

This report deals with the probable impact of urban development on the magnitude and frequency of flooding in the lower reach of the Walnut creek Basin. Stream-modeling techniques, which include complete definition of unit hydroqraphs and precipitation loss-rate criteria, were utilized to evaluate the effects of urban development as measured by percentages of impervious area over the basin. A mathematical model, called HEC-1, was calibrated by using concurrent rainfall-runoff data collected at three gaging stations in the basin. The model parameters were regionalized to allow future users to estimate the model parameters for ungaged areas within the basin. Long-term rainfall data recorded at two nearby stations were employed as basic input to the calibrated model to generate annual peak discharges corresponding to selected degrees of urbanization. Results are presented in tables and graphs, which compare the pre-urban and urban flood flow characteristics of the lower reach of the Walnut Creek basin.

Iowa↗

USGS1991

Hydrogeology and ground-water flow in the carbonate rocks of the Little Lehigh Creek basin, Lehigh County, Pennsylvania

The Little Lehigh Creek basin is underlain mainly by a complex assemblage of highly-deformed Cambrian and Ordovician carbonate rocks. The Leithsville Formation, Allentown Dolomite, Beekmantown Group, and Jacksonburg Limestone act as a single hydrologic unit. Ground water moves through fractures and other secondary openings and generally is under water-table conditions. Median annual ground-water discharge (base flow) to Little Lehigh Creek near Allentown (station 01451500) during 1946-86 was 12.97 inches or 82 percent of streamflow. Average annual recharge for 1975-83 was 21.75 inches. Groundwater and surface-water divides do not coincide in the basin. Ground-water underflow from the Little Lehigh Creek basin to the Cedar Creek basin in 1987 was 4 inches per year. A double-mass curve analysis of the relation of cumulative precipitation at Allentown to the flow of Schantz Spring for 1956-84 showed that cessation of quarry pumping and development of ground water for public supply in the Schantz Spring basin did not affect the flow of Schantz Spring. Ground-water flow in the Little Lehigh Creek basin was simulated using a finite-difference, two-dimensional computer model. The geologic units in the modeled area were simulated as a single water-table aquifer. The 134-squaremile area of carbonate rocks between the Lehigh River and Sacony Creek was modeled to include the natural hydrologic boundaries of the ground-water-flow system. The ground-water-flow model was calibrated under steady-state conditions using 1975-83 average recharge, evapotranspiration, and pumping rates. Each geologic unit was assigned a different hydraulic conductivity. Initial aquifer hydraulic conductivity was estimated from specific-capacity data. The average (1975-83) water budget for the Little Lehigh Creek basin was simulated. The simulated base flow from the carbonate rocks of the Little Lehigh Creek basin above gaging station 01451500 is 11.85 inches per year. The simulated ground-water underflow from the Little Lehigh Creek basin to the Cedar Creek basin is 4.04 inches per year. For steady-state calibration, the root-mean-squared difference between observed and simulated heads was 21.19 feet. The effects of increased ground-water development on base flow and underflow out of the Little Lehigh Creek basin for average and drought conditions were simulated by locating a hypothetical well field in different parts of the basin. Steady-state simulations were used to represent equilibrium conditions, which would be the maximum expected long-term effect. Increased ground-water development was simulated as hypothetical well fields pumping at the rate of 15, 25, and 45 million gallons per day in addition to existing ground-water withdrawals. Four hypothetical well fields were located near and away from Little Lehigh Creek in upstream and downstream areas. The effects of pumping a well field in different parts of the Little Lehigh Creek basin were compared. Pumping a well field located near the headwaters of Little Lehigh Creek and away from the stream would have greatest effect on inducing underflow from the Sacony Greek basin and the least effect on reducing base flow and underflow to the Ceda^r Creek basin. Pumping a well field located near the headwaters of Little Leh|igh Creek near the stream would have less impact on inducing underflow from|the Sacony Creek basin and a greater impact on reducing the base flow of Little Lehigh Creek because more of the pumpage would come from diverted base flow. Pumping a well field located in the downstream area of the Little Lehigh Creek basin away from the stream would have the greatest effect on the underflow to the Cedar Creek basin. Pumping a well field located in the downstream area of the Little Lehigh Creek basin near the stream would have the greatest effect on reducing the base flow of Little Lehigh Cteek. Model simulations show that groundwater withdrawals do not cause a proportional reduction in base flow. Under average conditions, ground-water withdrawals are equal to 48 to 70 percent of simulated base-flow reductions; under drought conditions, ground-water withdrawals are equal to 35 to 73 percent of simulated base-flow reductions. The hydraulic effects of pumping largely depend on well location. In the Little Lehigh basin, surface-water and ground-water divides do not coincide, and ground-water development, especially near surface-water divides, can cause ground-water divides to shift and induce ground-water underflow from adjacent basins. Large-scale ground-water pumping in a basin may not produce expected reductions of base flow in that basin because of shifts in the ground-water divide; however, such shifts can reduce base flow in adjacent surface-water basins.

Water-Resources Investigations Report↗

USGS2016

Predictive mapping of seabirds, pinnipeds and cetaceans off the Pacific Coast of Washington

About this report This report supports Washington-led marine spatial planning and responsible stewardship of natural and cultural resources by the Olympic Coast National Marine Sanctuary. Washington state agencies and the sanctuary continually seek the best available science to improve management of marine uses and stewardship of resources (Etheridge et al., 2010; Washington Department of Fish and Wildlife, 2015a). This report and associated data provide new, state- and sanctuary-requested information on seabird, pinniped, and cetacean distributions. Through spatial planning, information on species distributions can help to identify high-value conservation areas, minimize adverse effects of ocean uses and mitigate impacts of coastal hazards. Correspondingly, the Washington Department of Fish and Wildlife has already begun to use the maps of predicted relative density presented in this report to identify ecologically important areas off the Pacific Coast of Washington and apply this information to plan for offshore renewable energy development. This is the culmination of three years of work to compile information on seabirds, pinnipeds, and cetaceans, and advance a modeling framework that can integrate data sets and develop accurate predictions of relative density for important species off the Pacific Coast of Washington. Previous reports, which evaluated existing datasets of at-sea observations (Menza et al., 2014; Kracker and Menza, 2015) and presented superseded versions of seabird models (Menza et al., 2015), provided base information for this report. In addition to the maps in this published report, all new seabird, pinniped and cetacean predictions will be made publicly available as digital geospatial data through the National Centers for Environmental Information. This research supports the National Oceanic and Atmospheric Administration (NOAA) Coastal Zone Management Program, a voluntary partnership between the federal government and U.S. coastal and Great Lakes states and territories authorized by the Coastal Zone Management Act (CZMA) of 1972 to address national coastal issues. The act provides the basis for protecting, restoring, and responsibly developing our nation’s diverse coastal communities and resources. To meet the goals of the CZMA, the national program takes a comprehensive approach to coastal resource management – balancing the often competing and occasionally conflicting demands of coastal resource use, economic development, and conservation. A wide range of issues are addressed through the program, including coastal development, water quality, public access, habitat protection, energy facility siting, ocean governance and planning, coastal hazards, and climate change. Accurate maps of seabird and marine mammal distributions are an important tool for making informed management decisions that affect all of these issues.

Washington↗

USGS2024

Consumer isoscapes reveal heterogeneous food webs in deep-sea submarine canyons and adjacent slopes

The deep sea is the largest biome on earth, but one of the least studied despite its critical role in global carbon cycling and climate buffering. Deep-sea organisms largely rely on particulate organic matter from the surface ocean for energy – these organisms in turn play critical roles in energy transport, transformation, storage, and sequestration of carbon. Within the deep sea, submarine canyons are amongst the most complex and dynamic environments in our oceans, where varied morphology, powerful currents, and variable nutrient conditions influence the distribution of species and transport of organic material throughout the water column and the seafloor. Significant habitat heterogeneity provides ideal substrates for cold-water corals, making submarine canyons of interest to conservation and management. However, how these and other topographic features in the deep ocean influence energy flow and trophic pathways is poorly known. Thus, submarine canyons serve as model systems to track variability in organic material flux and consequential utilization and assimilation by the benthos. In this study, we used an extensive stable isotope dataset to examine food-web structure in Baltimore and Norfolk submarine canyons and compared them to their adjacent slopes located along the U.S. Atlantic margin. Linear models were used to construct geospatially-explicit consumer isoscapes that predicted variation in carbon and nitrogen isotopes across the canyon-slope seascape, providing a predictive map from which to test hypotheses on the distribution and flow of energy resources, relevant to understanding whole community function. Communities were composed of isotopically diverse feeding groups with photosynthetically-derived organic carbon providing the basal food resource. Canyon communities were distinct from the slope, with canyon consumers significantly 13 C-depleted, indicating a greater supply and/or utilization of fresh organic matter compared to the slope. Isoscapes for benthic and suspension feeders were distinct, possibly due to the consumption of different quality organic matter sources (fresh = suspension feeders, old = benthic feeders), each with distinct isotope composition. To our knowledge, our modeled isoscapes represent the first spatially extensive isotopic maps of deep-sea consumers, providing insights into regional-scale variation in stable carbon and nitrogen isotopes for different consumer groups. They provide a baseline for tracking climate-change induced fluctuations in the quality and availability of surface primary production and the consequential impact to benthic communities, which play critical roles in carbon cycling in our world’s oceans.

Progress in Oceanography↗