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USGS2019

Evaluating environmental change and behavioral decision-making for sustainability policy using an agent-based model: A case study for the Smoky Hill River Watershed, Kansas

Sustainability has been at the forefront of the environmental research agenda of the integrated anthroposphere, hydrosphere, and biosphere since the last century and will continue to be critically important for future environmental science. However, linking humans and the environment through effective policy remains a major challenge for sustainability research and practice. Here we address this gap using an agent-based model (ABM) for a coupled natural and human systems in the Smoky Hill River Watershed (SHRW), Kansas, USA. For this freshwater-dependent agricultural watershed with a highly variable flow regime influenced by human-induced land-use and climate change, we tested the support for an environmental policy designed to conserve and protect fish biodiversity in the SHRW. We develop a proof of concept interdisciplinary ABM that integrates field data on hydrology, ecology (fish richness), social-psychology (value-belief-norm) and economics, to simulate human agents' decisions to support environmental policy. The mechanism to link human behaviors to environmental changes is the social-psychological sequence identified by the value-belief-norm framework and is informed by hydrological and fish ecology models. Our results indicate that (1) cultural factors influence the decision to support the policy; (2) a mechanism modifying social-psychological factors can influence the decision-making process; (3) there is resistance to environmental policy in the SHRW, even under potentially extreme climate conditions; and (4) the best opportunities for policy acceptance were found immediately after extreme environmental events. The modeling approach presented herein explicitly links biophysical and social science has broad generality for sustainability problems.

Kansas↗

USGS2016

Quantification of human-associated fecal indicators reveal sewage from urban watersheds as a source of pollution to Lake Michigan

Sewage contamination of urban waterways from sewer overflows and failing infrastructure is a major environmental and public health concern. Fecal coliforms (FC) are commonly employed as fecal indicator bacteria, but do not distinguish between human and non-human sources of fecal contamination. Human Bacteroides and human Lachnospiraceae , two genetic markers for human-associated indicator bacteria, were used to identify sewage signals in two urban rivers and the estuary that drains to Lake Michigan. Grab samples were collected from the rivers throughout 2012 and 2013 and hourly samples were collected in the estuary across the hydrograph during summer 2013. Human Bacteroides and human Lachnospiraceae were highly correlated with each other in river samples (Pearson’s r = 0.86), with average concentrations at most sites elevated during wet weather. These human indicators were found during baseflow, indicating that sewage contamination is chronic in these waterways. FC are used for determining total maximum daily loads (TMDLs) in management plans; however, FC concentrations alone failed to prioritize river reaches with potential health risks. While 84% of samples with >1000 CFU/100 ml FC had sewage contamination, 52% of samples with moderate (200–1000 CFU/100 ml) and 46% of samples with low (<200 CFU/100 ml) FC levels also had evidence of human sewage. Load calculations in the in the Milwaukee estuary revealed storm-driven sewage contamination varied greatly among events and was highest during an event with a short duration of intense rain. This work demonstrates urban areas have unrecognized sewage inputs that may not be adequately prioritized for remediation by the TMDL process. Further analysis using these approaches could determine relationships between land use, storm characteristics, and other factors that drive sewage contamination in urban waterways.

Wisconsin↗

USGS2022

Loss of street tree canopy increases stormwater runoff

Urban forests have largely been overlooked for the role they play in reducing stormwater runoff volume by using hydrologic processes such as interception (rainfall intercepted by tree canopy), evapotranspiration (the transfer of water from vegetation into the atmosphere) and infiltration (percolation of rainwater into the Earth’s soil). Early research into the effects of trees on urban stormwater runoff used simple estimates based on assumptions of canopy coverage and design storm criteria. In a review of available literature on how capable urban trees are at reducing runoff, the Center for Watershed Protection (2017) found only six studies; three of them used measured data from a single plot, and the other three used models. When identifying gaps in research on the role of trees in stormwater management, Kuehler and others (2017) highlighted the need for studies that scale the local effects of urban trees to the larger sewershed catchment area, allowing a more holistic understanding of the urban tree canopy effects on hydrology. For these reasons, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, U.S. Forest Service, and the University of Wisconsin, quantified the effect of removing urban street trees and their canopy on stormwater generation in a medium-density residential area. Using a paired-catchment experimental design, rainfall-runoff relations were characterized in two medium-density residential catchments in Fond du Lac, Wisconsin, during May through September in 2018–20. Results of the study are detailed in Selbig and others (2022). During the calibration phase, hydrograph metrics from paired runoff events were used to develop the relation between the control and test catchments with street trees in place. The ability to measure changes to the rainfall-runoff response after removal of tree canopy was made possible by an aggressive tree removal program by the city as a response to rapid infestation from the Agrilus planipennis (emerald ash borer). In March 2020, a total of 31 street trees were removed at the onset of the treatment period, resulting in a loss of 2,990 square meters of canopy over streets, driveways, sidewalks, and grassed areas.

Wisconsin↗

USGS2001

Processes controlling the episodic streamwater transport of atrazine and other agrichemicals in an agricultural watershed

Episodic streamwater transport of atrazine (a common agricultural herbicide) and nutrients has been observed throughout agricultural watersheds in the United States and poses a serious threat to the quality of its water resources. Catchment-scale atrazine and nutrient transport processes after agricultural application are still poorly understood, and predicting episodic streamwater composition remains an elusive goal. We instrumented a 1.2-km 2 agricultural catchment near Harrisonburg, Virginia, and examined streamwater, overland flow, soil water, groundwater, and rainfall during the summer of 1998. Storm chemographs demonstrated different patterns for constituents derived primarily from weathering (silica and calcium), compared to constituents derived primarily from early spring land applications (nitrate, atrazine, DOC, potassium, chloride, and sulfate). During storms, the concentrations of silica and calcium decreased, the atrazine response was variable, and the concentrations of nitrate, DOC, potassium, chloride, and sulfate increased; the elevated nitrate signal lagged several hours behind the other elevated constituents. Graphical and statistical analyses indicated a relatively stable spring-fed baseflow was modified by a mixture of overland flow and soil water. A rapid, short-duration overland-flow pulse dominated the streamflow early in the event and contributed most of the potassium, DOC, chloride, suspended sediment, and atrazine. A longer-duration soil–water pulse dominated the streamflow later in the event and contributed the nitrate as well as additional potassium, DOC, sulfate, and atrazine. The contributions to the episodic streamflow were quantified using a flushing model in which overland-flow and soil–water concentrations decreased exponentially with time during an episode. Flushing time constants for the overland-flow and soil–water reservoirs were calculated on a storm-by-storm basis using separate tracers for each time-variable reservoir. Initial component concentrations were estimated through regression analyses. Mass-balance calculations were used for flow separations and to predict the observed streamwater composition. Model forecasts indicated that reduced fertilizer and pesticide application (rather than elimination of overland-flow or soil–water contributions) was necessary to improve the episodic streamwater composition. This study provides important additional understanding of the catchment-scale processes by which land-applied pesticides and nutrients can move through agricultural systems.

Virginia↗

USGS2022

Passage of adult coho salmon (Oncorhynchus kisutch) over Lake Creek Falls, Oregon, 2019

Across the Pacific Northwest, there are many examples of artificial structures created to allow passage of upstream-migrating salmon over natural barriers. We studied upstream passage across three structures installed in 1989 to allow passage of salmon over Lake Creek Falls, a series of three natural waterfalls at the outlet of Triangle Lake on Lake Creek, in the central Oregon Coast Range (lat 123.57508°; long 44.15735°). To track upstream passage by adult coho salmon ( Oncorhynchus kisutch ), 87 fish were tagged using gastrically implanted radio tags. Tracking was accomplished with a series of stationary receivers installed to detect crossings at each of three structures—over Lake Creek Falls using two upstream Denil-type ladders and a bypass downstream constructed to mimic a natural side channel. Tracking spanned the upstream migration and spawn timing for adult coho salmon in the basin and extended from October 2019 to February 2020. A total of 15 coho salmon (17 percent) were tagged in October, 30 coho salmon (35 percent) were tagged in November, and 42 coho salmon (48 percent) were tagged in December. Later-than-normal precipitation and associated low discharge delayed upstream migrations. Accordingly, most fish arrived late in the season (late November and December) and in sudden flushes with the erratic rain events. Fish that were tagged earlier were more likely to cross all three ladders, with more than 93 percent of fish tagged in October compared to 46.7 and 19.0 percent of November and December fish passing, respectively. The decline in passage rate could be attributed to the overlapping influences of stream discharge and advanced stage of maturation (lower energy reserves) of fish later in the season. Near the end of the study, both fish that crossed and fish obstructed by barriers were observed in tributaries known to be used for spawning by coho salmon. Without a much longer-term study involving many more fish than the current study, more intensive tracking, and coverage of different flow years, firm conclusions are difficult to draw regarding the overall influences of the passage structures on the likelihood of upstream passage by adult coho salmon. However, substantial numbers of fish are capable of crossing during certain conditions. The population-level consequences of the barriers on spawning distribution and the production of coho salmon in the watershed are not clear. Additional empirical study or population modeling could be used to address this question in more detail.

Oregon↗

USGS2016

Hydrologic and hydraulic analyses for the Black Fork Mohican River Basin in and near Shelby, Ohio

Hydrologic and hydraulic analyses were done for selected reaches of five streams in and near Shelby, Richland County, Ohio. The U.S. Geological Survey (USGS), in cooperation with the Muskingum Watershed Conservancy District, conducted these analyses on the Black Fork Mohican River and four tributaries: Seltzer Park Creek, Seltzer Park Tributary, Tuby Run, and West Branch. Drainage areas of the four stream reaches studied range from 0.51 to 60.3 square miles. The analyses included estimation of the 10-, 2-, 1-, and 0.2-percent annual-exceedance probability (AEP) flood-peak discharges using the USGS Ohio StreamStats application. Peak discharge estimates, along with cross-sectional and hydraulic structure geometries, and estimates of channel roughness coefficients were used as input to step-backwater models. The step-backwater water models were used to determine water-surface elevation profiles of four flood-peak discharges and a regulatory floodway. This study involved the installation of, and data collection at, a streamflow-gaging station (Black Fork Mohican River at Shelby, Ohio, 03129197), precipitation gage (Rain gage at Reservoir Number Two at Shelby, Ohio, 405209082393200), and seven submersible pressure transducers on six selected river reaches. Two precipitation-runoff models, one for the winter events and one for nonwinter events for the headwaters of the Black Fork Mohican River, were developed and calibrated using the data collected. With the exception of the runoff curve numbers, all other parameters used in the two precipitation-runoff models were identical. The Nash-Sutcliffe model efficiency coefficients were 0.737, 0.899, and 0.544 for the nonwinter events and 0.850 and 0.671 for the winter events. Both of the precipitation-runoff models underestimated the total volume of water, with residual runoff ranging from -0.27 inches to -1.53 inches. The results of this study can be used to assess possible mitigation options and define flood hazard areas that will contribute to the protection of life and property. This study could also assist emergency managers, community officials, and residents in determining when flooding may occur and planning evacuation routes during a flood.

Ohio↗

USGS2011

Temporal and spatial distribution of landslides in the Redwood Creek Basin, Northern California

Mass movement processes are a dominant means of supplying sediment to mountainous rivers of north coastal California, but the episodic nature of landslides represents a challenge to interpreting patterns of slope instability. This study compares two major landslide events occurring in 1964-1975 and in 1997 in the Redwood Creek basin in north coastal California. In 1997, a moderate-intensity, long-duration storm with high antecedent precipitation triggered 317 landslides with areas greater than 400 m 2 in the 720-km 2 Redwood Creek basin. The intensity-duration threshold for landslide initiation in 1997 was consistent with previously published values. Aerial photographs (1:6,000 scale) taken a few months after the 1997 storm facilitated the mapping of shallow debris slides, debris flows, and bank failures. The magnitude and location of the 1997 landslides were compared to the distributions of landslides generated by larger floods in 1964, 1972, and 1975. The volume of landslide material produced by the 1997 storm was an order of magnitude less than that generated in the earlier period. During both periods, inner gorge hillslopes produced many landslides, but the relative contribution of tributary basins to overall landslide production differed. Slope stability models can help identify areas susceptible to failure. The 22 percent of the watershed area classified as moderately to highly unstable by the SHALSTAB slope stability model included locations that generated almost 90 percent of the landslide volume during the 1997 storm.

California↗

USGS2009

Environmental Impact of the Contact and Sonoma Mercury Mines on Water, Sediment, and Biota in Anna Belcher and Little Sulphur Creek Watersheds, Sonoma County, California

The Contact and Sonoma mercury (Hg) deposits are among the youngest Hg deposits in the Coast Range Hg mineral belt and are located in the western part of the Clear Lake volcanic field in Sonoma County, California. The mine workings and tailings are located in the headwaters of Anna Belcher Creek, which is a tributary to Little Sulphur Creek. The Contact Hg mine produced about 1,000 flasks of Hg, and the Sonoma mine produced considerably less. Waste rock and tailings eroded from the Contact and Sonoma mines have contributed Hg-enriched mine waste material to the headwaters of Anna Belcher Creek. The mines are located on federal land managed by the U.S. Bureau of Land Management (USBLM). The USBLM requested that the U.S. Geological Survey (USGS) measure and characterize Hg and other geochemical constituents in tailings, sediment, water, and biota at the Contact and Sonoma mines and in Anna Belcher and Little Sulphur Creeks. This report is made in response to the USBLM request, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to removal of Hg-contaminated mine waste from the Contact and Sonoma mines as a means of reducing Hg transport to Anna Belcher and Little Sulphur Creeks. This report summarizes data obtained from field sampling of mine tailings, waste rock, sediment, and water at the Contact and Sonoma mines that was initiated on April 20 during a storm event, and on June 19, 2001. Further sampling of water, sediment, and biota in a pond and tributaries that drain from the mine area was completed on April 1, 2003. Our results permit a preliminary assessment of the mining sources of Hg and associated chemical constituents that could elevate levels of monomethyl Hg (MMeHg) in tributaries and biota that are impacted by historic mining.

Open-File Report↗

USGS2019

Integrating stream gage data and Landsat imagery to complete time-series of surface water extents in Central Valley, California

Accurate monitoring of surface water location and extent is critical for the management of diverse water resource phenomena. The multi-decadal archive of Landsat satellite imagery is punctuated by missing data due to cloud cover during acquisition times, hindering the assembly of a continuous time series of inundation dynamics. This study investigated whether streamflow volume measurements could be integrated with satellite data to fill gaps in monthly surface water chronologies for the Central Valley region of California, USA, from 1984 to 2015. We aggregated measurements of maximum monthly water extent within each of the study area’s 50 8-digit hydrologic unit code [HUC] watersheds from two Landsat-derived datasets: the European Commission’s Joint Research Centre (JRC) Monthly Water History and the U.S. Geological Survey Dynamic Surface Water Extent (DSWE). We calculated Spearman rank correlation coefficients between water extent values in each HUC and streamflow discharge data. Linear regression fits of the water extent/streamflow data pairs with the highest correlations served as the basis for interpolation of missing imagery surface water values on a HUC-wise basis. Results show strong (ρ > 0.7) maximum correlations in 11 (22.4%) and 25 (51.0%) HUCs for the DSWE and JRC time series, respectively, when comparisons were restricted to imagery and gages co-located in each HUC. Strong maximum correlations occurred in 39 (79.6%; DSWE) and 42 (85.7%; JRC) HUCs when imagery was paired with discharge data from any study area gage, providing a solid basis for reconstruction of water extent values. We generated continuous time series of 30+ years in 35 HUCs, demonstrating that this technique can provide quantitative estimates of historical surface water extents and elucidate flooding or drought events over the period of data collection. Results of a non-parametric trend analysis of the long-term time series on an annual, seasonal, and monthly basis varied among HUCs, though most trends indicate an increase in surface water over the past 30 years.

California↗

USGS2026

Storm surge barriers reduce seaward sediment supply to lagoonal estuaries

Numerical simulations with realistic forcing of fixed infrastructure for a proposed storm surge barrier for a lagoonal estuary, Jamaica Bay (New York, USA), are analyzed during typical forcing conditions to assess alterations to flow and sediment transport with the barrier open. Lagoonal estuaries are shallow and have modest watershed freshwater and sediment inputs, so sediment delivery is primarily from offshore by tidal transport. The storm surge barrier infrastructure across the inlet channel reduces cross-sectional area and increases tidal velocities, increasing frictional and form drag. The overall reduction in tidal amplitude is about 1%, but the quarterdiurnal M 4 component decreases by 11%. The salinity and stratification in the estuary are only slightly modified by mixing by stronger velocities near the barrier. Sediment transport in the inlet scales approximately with tidal velocity cubed and net landward transport is driven by flood-dominant tidal asymmetry. Additionally, tidal asymmetry in the jet flow through barrier openings causes a divergence in sediment transport within several kilometers. The alterations to the tidal currents reduce sediment import to the bay by 20% for fine sand; transport of sediment with slower settling velocities is less affected, with reductions of 3% for medium silt and <1% for fine silt. The study examined tidal exchange with an open barrier, but the overall impact also depends on barrier operations during major storm events. The impacts of barrier infrastructure on lagoonal estuaries are distinct from other estuary types due to their modest freshwater input, predominance of tidal transport, and offshore sediment supply.

New York↗

USGS2024

Watershed hydrology assessment for the Lower Colorado River Basin. Appendix D: RiverWare analyses

RiverWare is a river system modeling tool developed by CADSWES (Center of Advanced Decision Support for Water and Environmental Systems) that allows the user to simulate complex reservoir operations and perform period-of-record analyses for different scenarios. For the InFRM hydrology studies, RiverWare is used to generate a homogeneous regulated POR by simulating the basin as if the reservoirs and their current rule sets had been present in the basin for the entire time period. Statistical analyses can then be performed on the extended records at the gages. This report summarizes the RiverWare portion of the hydrologic analysis being completed for the InFRM Hydrology study of the Colorado River Basin. The RiverWare model described in this chapter presents development of the Colorado River Basin hydrology, which mimics current operational conditions. The use of the RiverWare program allows for data extension to periods prior to dam construction. The utilization of longer gage record improves discharge frequency results and increases the confidence of the analysis being performed. The modeling evaluation criteria are: (1) evaluate output based on validating policies and functions, and (2) prioritize operation based on surcharge and flood control. A detailed explanation of the Colorado River Basin POR hydrology will be in a later section. Calibration results will also be shown that illustrate the overall model performance for the POR. The time window simulation run is for January 01, 1930 – September 30, 2019. This time window captures all big events occurred over the Colorado River basin. Each simulated water year was inspected individually to better validate the results. Historical pool elevations along with observed inflows and outflows were compared against the model simulated results.

Texas↗

USGS2019

Development of a flood-inundation map library and precipitation-runoff modeling for the Clear Fork Mohican River in and near Bellville, Ohio

The U.S. Geological Survey (USGS), in cooperation with the Muskingum Watershed Conservancy District, led hydrologic and hydraulic analyses within the Clear Fork Mohican River Basin in and near Bellville, Ohio. The analyses included the development of digital flood-inundation maps for an approximately 2.5-mile reach of the Clear Fork Mohican River and the development of a precipitation-runoff model for a portion of the Clear Fork Mohican River Basin. Data collection for the study involved the installation and operation of 2 streamgages (Clear Fork Mohican River at Bellville, Ohio, and Cedar Fork above Bellville, Ohio); 1 lake-level gage (Clear Fork Reservoir near Lexington, Ohio); 2 precipitation gages (Clear Fork Reservoir near Lexington, Ohio, and Rain Gage at Cedar Fork above Bellville, Ohio); and 12 submersible pressure transducers on Clear Fork Mohican River and 4 of its tributaries. Data collection also included field surveys of hydraulic structures and channel cross sections. Flood profiles were computed for the 2.5-mile reach of the Clear Fork Mohican River by means of a one-dimensional step-backwater model. The model was calibrated to 16 measured events and to a portion (stages 9 to 11 feet) of the current stage-streamflow relation at the USGS streamgage Clear Fork Mohican River at Bellville, Ohio, and to stage recorded at a submersible pressure transducer site near the downstream study limit. After calibration the step-backwater model was used to compute nine flood profiles for stages ranging from 9 to 17 feet. The flood profiles were then used in combination with a digital elevation model to delineate the area that would be inundated at each stage. A precipitation-runoff model was developed and calibrated using data from the streamgage, precipitation gage, and 11 submersible pressure transducers. The modeling included data during 10 runoff events that were used for model calibration and validation, with focus on 6 events. The Nash-Sutcliffe model efficiency coefficients for six peak streamflow events ranged from 0.459 to 0.851. The models produced by this study can be used to assess possible flood mitigation options and define flood hazard areas that could contribute to the protection of life and property. The availability of flood-inundation maps, internet information from USGS streamgages, and forecasted stages from the National Weather Service could provide emergency management personnel and residents with information on forecasting floods, appropriate flood response activities, and post-flood recovery efforts.

Ohio↗

USGS2018

Wetlands inform how climate extremes influence surface water expansion and contraction

Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage. From these findings, we can expect that shifts in precipitation and evaporative demand will have uneven effects on surface water quantity. Accurate predictions regarding the effect of climate change on surface water quantity will require consideration of hydrology-related landscape characteristics including wetland storage and arrangement.

Prairie Pothole Regino↗

USGS2001

Topographic controls on the chemistry of subsurface stormflow

Models are needed that describe how topography and other watershed characteristics affect the chemical composition of runoff waters, yet little spatially distributed data exist to develop such models. A topographically driven flushing mechanism for nitrate (NO3-) and dissolved organic carbon has been described in recent literature; however, this mechanism has not yet been thoroughly tested. A 24 ha catchment in the Catskill Mountains of New York was clearcut in the winter of 1996-97, resulting in elevated NO3- concentrations in soil water, groundwater and streamflow. We sampled shallow subsurface stormflow (SSSF) and streamflow six times during the spring and summer of 1998, 1 year after the harvest. We used a spatially distributed network of piezometers to investigate the relationship between topography and SSSF chemistry. Several indices of topography were computed, including the commonly employed topographic index of Beven and Kirkby (1979; Hydrological Sciences Bulletin 24: 43-69). Topographic index was positively correlated with NO3- concentrations in SSSF. The strength of the NO3- -topography relationship was best explained by antecedent soil temperature and antecedent precipitation conditions. Results suggest a topographically driven flushing of high NO3- shallow soil at the site during storm events. Copyright ?? 2001 John Wiley & Sons, Ltd.

Hydrological Processes↗

USGS2014

Water-quality and biological conditions in selected tributaries of the Lower Boise River, southwestern Idaho, water years 2009-12

Water-quality conditions were studied in selected tributaries of the lower Boise River during water years 2009–12, including Fivemile and Tenmile Creeks in 2009, Indian Creek in 2010, and Mason Creek in 2011 and 2012. Biological samples, including periphyton biomass and chlorophyll-a, benthic macroinvertebrates, and fish were collected in Mason Creek in October 2011. Synoptic water-quality sampling events were timed to coincide with the beginning and middle of the irrigation season as well as the non-irrigation season, and showed that land uses and irrigation practices affect water quality in the selected tributaries. Large increases in nutrient and sediment concentrations and loads occurred over relatively short stream reaches and affected nutrient and sediment concentrations downstream of those reaches. Escherichia coli (E. coli) values increased in study reaches adjacent to pastured lands or wastewater treatment plants, but increased E. coli values at upstream locations did not necessarily affect E. coli values at downstream locations. A spatial loading analysis identified source areas for nutrients, sediment, and E. coli , and might be useful in selecting locations for water-quality improvement projects. Effluent from wastewater treatment plants increased nutrient loads in specific reaches in Fivemile and Indian Creeks. Increased suspended-sediment loads were associated with increased discharge from irrigation returns in each of the studied tributaries. Samples collected during or shortly after storms showed that surface runoff, particularly during the winter, may be an important source of nutrients in tributary watersheds with substantial agricultural land use. Concentrations of total phosphorus, suspended sediment, and E. coli exceeded regulatory water-quality targets or trigger levels at one or more monitoring sites in each tributary studied, and exceedences occurred during irrigation season more often than during non-irrigation season. As with water-quality sampling results, bottom-sediment samples analyzed for contaminants of emerging concern indicated that adjacent land uses can affect in-stream conditions. Contaminants of emerging concern were detected in four categories: urban compounds, industrial compounds, fecal steroids, and personal care products. Compounds in one or more of the four contaminant categories were detected at higher concentrations in upstream sites than in downstream sites in the tributaries and in the lower Boise River. High concentrations of compounds in upstream locations indicated that adjacent land use might be an important factor in contributing contaminants of emerging concern to the lower Boise River watershed. Expanded monitoring at Mason Creek near the mouth included a streamgage, a continuous water-quality monitor, and monthly water-quality sample collection. Data collected during expanded monitoring efforts at Mason Creek near the mouth provided information to develop and compare water-quality models. Regression models were developed using turbidity, discharge, and seasonality as surrogates to estimate concentrations of water-quality constituents. Daily streamflow also was used in a load model to estimate daily loads of water-quality constituents. Surrogate regression models may be useful for long-term monitoring and generally performed better than other models to estimate concentrations and loads of total phosphorus, total nitrogen, and suspended sediment in Mason Creek. Biological sampling results from Mason Creek showed low periphyton biomass and chlorophyll-a concentrations compared to those historically measured in the Boise River near Parma, Idaho, during October and November. The most abundant invertebrate found in Mason Creek was the highly tolerant and invasive New Zealand mudsnail ( Potamopyrgus antipodarum ). The presence of small rainbow trout (90 millimeters) may indicate salmonid spawning in Mason Creek. The rangeland-fish-index score of 58 for Mason Creek is comparable to rangeland-fish-index scores calculated for the Boise River near Middleton, indicating intermediate biotic condition.

Idaho↗

USGS2015

Long-term decrease in satellite vegetation indices in response to environmental variables in an iconic desert riparian ecosystem: the Upper San Pedro, Arizona, United States

The Upper San Pedro River is one of the few remaining undammed rivers that maintain a vibrant riparian ecosystem in the southwest United States. However, its riparian forest is threatened by diminishing groundwater and surface water inputs, due to either changes in watershed characteristics such as changes in riparian and upland vegetation, or human activities such as regional groundwater pumping. We used satellite vegetation indices to quantify the green leaf density of the groundwater-dependent riparian forest from 1984 to 2012. The river was divided into a southern, upstream (mainly perennial flow) reach and a northern, downstream (mainly intermittent and ephemeral flow) reach. Pre-monsoon (June) Landsat normalized difference vegetation index (NDVI) values showed a 20% drop for the northern reach (P < 0·001) and no net change for the southern reach (P > 0·05). NDVI and enhanced vegetation index values were positively correlated (P < 0·05) with river flows, which decreased over the study period in the northern reach, and negatively correlated (P < 0·05) with air temperatures in both reaches, which have increased by 1·4 °C from 1932 to 2012. NDVI in the uplands around the river did not increase from 1984 to 2012, suggesting that increased evapotranspiration in the uplands was not a factor in reducing river flows. Climate change, regional groundwater pumping, changes in the intensity of monsoon rain events and lack of overbank flooding are feasible explanations for deterioration of the riparian forest in the northern reach.

Arizona↗

USGS2000

Stable isotope evolution and paleolimnology of ancient Lake Creede

The lacustrine carbonate and travertine (tufa) deposits of ancient Lake Creede preserve a remarkable record of the isotopic evolution of the lake. That record indicates that the δ18O of the lake water, and by analogy its salinity, evolved through evaporation. Limited and less reliable data on hydrous minerals and fluid inclusions in early diagenetic carbonates indicate that the δD of the lake waters also evolved through evaporation. The isotope data place restrictions on models of the physical limnology of the lake and its evolution. The closed-basin Lake Creede formed shortly after collapse of the 26.9 Ma Creede caldera. Throughout most of its history it occupied the northern three quarters of the moat between the resurgent dome and wall of the caldera. The Creede Formation was deposited in the basin, dominantly as lacustrine sediments. Travertine mounds interfinger with Creede Formation sediments along the inner and outer margins of the lake basin. An estimated one-half of the original thickness of the Creede Formation has been lost mainly to erosion although scattered remnants of the upper portion remain on the caldera walls. Two diamond core holes (CCM-1 and CCM-2) sampled the uneroded portion of the Creede Formation as part of the U.S. Continental Drilling Program. Volcaniclastic material, including tuff units deposited directly into the lake and ash washed in from the watershed, compose the main lithologies of the Creede Formation. These volcaniclastic strata were produced by episodic ring-fracture volcanism. Lacustrine carbonates make up about 15% of the section sampled by drill core. They occur as 1 mm to 2 cm low-Mg calcite laminae alternating with siliciclastic laminae in scattered intervals throughout the preserved section. The carbonate laminae are accumulations of 5–20 µm crystallites (microsparites) and brine shrimp fecal pellets (peloids) composed mainly of microsparite particles. Low-Mg calcite also occurs as an early diagenetic replacement of gypsum or ikaite (CaCO3 ·6H2O) crystals grown displacively in the muds and silts near the water-sediment interface (rice grains). Other studies indicate that aragonite was the original CaCO3 precipitate forming the microsparite and peloidal laminae and that it converted to calcite during burial diagenesis. Samples from CCM-2 and nearby outcrop do not appear to have undergone significant isotope exchange during recrystallization. Samples from CCM-1 and nearby outcrop, however, appear to have undergone extensive oxygen isotope exchange with meteoric water-dominated fluids possibly during a local 17.6 Ma hydrothermal event. The δ18O-δ13C data set produced by microsampling of individual carbonate lamellae and rice grains is exceptional in several aspects and provides important clues concerning the evolution of limnologic structure of the lake and its chemical and isotopic composition. Travertine and ikaite pseudomorphs in travertine deposits extend the record an additional 330 m above the collar of CCM-2. The δ18O values on CCM-2 samples range from 10.4‰ to 37.3‰ and δ13C values range from –10.8‰ to 9.6‰. The data fall into two distinct groups, a covariant group and an invariant group. The covariant group shows a strong negative covariance and a large range of δ18O and δ13C values. The negative covariance is opposite that normally reported for lacustrine carbonates. The large range of δ18O and δ13C values requires that the carbonates precipitated from waters have a large range of temperature and carbon and oxygen isotopic composition. The invariant group has a narrow range of large δ18O values (35‰ ± 2‰) and a wide range of δ13C values (–10.8‰ to 9.6‰), indicating precipitation from waters with a narrow range of temperature and δ18O but a wide range in δ13C of aqueous carbon. The ranges of isotope values for microsparite and peloid samples are virtually identical; two-thirds are in the covariant group. By contrast, the values for almost all rice grain samples are in the invariant group. The range in δ18O for all samples reflects precipitation from waters having varying proportions of deep, cold evaporated lake water and shallow, warmer meteoric water. The range for δ13C reflects varying proportions of organic carbon and carbon of volcanic or atmospheric origin, probably dominantly volcanic, in the aqueous carbon. Changes in the detailed carbon-oxygen isotope systematics with stratigraphic position define three periods of isotopic evolution of Lake Creede. Period I is represented by the lowest ~200 m of Creede Formation core in CCM-2. Analyses of individual microsparite and peloidal carbonate laminae within single thin sections of samples from that interval are tightly grouped. The data set as a whole shows a negative covariance. Rice grains are not found in this interval. Period II is represented by the succeeding 120 m of core in CCM-2. In that interval, δ13C-δ18O values for individual microsparite and peloidal carbonate laminae within single thin sections show strong negative covariance, and the set of values for the entire interval also shows strong negative covariance. Rice grains occur near the top of the interval. Period III is represented by the upper 225 m of CCM-2 core. In this interval, rice grains are abundant and δ13C-δ18O values for microsparite and peloidal laminae as well as rice grains fall in the invariant group. During Period I the lake was well mixed and the oxygen isotopic composition of the lake in the productive zone was only slightly influenced by short-term (e.g., annual) variations in the water budget of the lake. In Period II the lake was stratified, possibly with annual overturn. The productive zone included the mixolimnion and the isotopic composition of the microsparites and peloids reflected mixtures of shallow surface (meteoric) water containing volcanic or atmospheric CO2 (epilimnion) and cold underlying waters, the oxygen isotopic compositions of which had evolved through evaporation and were dominated by CO2 produced by the oxidation of organic matter (hypolimnion). During Period III the lake remained stratified. The productive zone was in the hypolimnion, probably due to a thinning of the epilimnion resulting from an increase in the surface area of the lake or a decrease in input waters reflecting a climate change. An upsection increase in values of δ18O for the heaviest samples during Periods I and II indicates evaporative concentration of 18O and, by analogy, salinity in the hypolimnion. The δD-δ18O evolution of the lake is inferred on theoretical evaporation trends, comparison to Mono Lake, and measurement of the δD in fluid inclusions in a calcite pseudomorph after ikaite. The δD-δ18O composition of the lake water followed a curved path that eventually hooked over at a nearly constant δ18O value for the lake of 2‰ ± 2‰ Travertine (tufa) mounds formed along the inner and outer margins of the lake in a zone of mixing of warm, volcanic CO2-bearing, meteoric waters and lake water. Ikaite crystals formed on the mounds from unmixed saline lake water, probably below the thermocline. As the position of the thermocline deepened, likely following the spring runoff, the ikaite was replaced by calcite and the resulting “pearls” were covered with travertine deposited from mixed meteoric and lake waters. The upsection increase in δ18O values of the carbonates, the long period of invariance of large δ18OH2O values, the presence of brine shrimp fecal pellets, and the inferred hooked δD-δ18O path are consistent with evidence from other studies that Lake Creede obtained significant salinity rather early in its history and certainly by the time the lake became permanently stratified.

Colorado↗

USGS2006

Use of sediment rating curves and optical backscatter data to characterize sediment transport in the Upper Yuba River watershed, California, 2001-03

Sediment transport in the upper Yuba River watershed, California, was evaluated from October 2001 through September 2003. This report presents results of a three-year study by the U.S. Geological Survey, in cooperation with the California Ecosystem Restoration Program of the California Bay-Delta Authority and the California Resources Agency. Streamflow and suspended-sediment concentration (SSC) samples were collected at four gaging stations; however, this report focuses on sediment transport at the Middle Yuba River (11410000) and the South Yuba River (11417500) gaging stations. Seasonal suspended-sediment rating curves were developed using a group-average method and non-linear least-squares regression. Bed-load transport relations were used to develop bed-load rating curves, and bed-load measurements were collected to assess the accuracy of these curves. Annual suspended-sediment loads estimated using seasonal SSC rating curves were compared with previously published annual loads estimated using the Graphical Constituent Loading Analysis System (GCLAS). The percent difference ranged from -85 percent to +54 percent and averaged -7.5 percent. During water year 2003 optical backscatter sensors (OBS) were installed to assess event-based suspended-sediment transport. Event-based suspended-sediment loads calculated using seasonal SSC rating curves were compared with loads calculated using calibrated OBS output. The percent difference ranged from +50 percent to -369 percent and averaged -79 percent. The estimated average annual sediment yield at the Middle Yuba River (11410000) gage (5 tons/mi2) was significantly lower than that estimated at the South Yuba River (11417500) gage (14 tons/mi2). In both rivers, bed load represented 1 percent or less of the total annual load throughout the project period. Suspended sediment at the Middle Yuba River (11410000) and South Yuba River (11417500) gages was typically greater than 85 percent silt and clay during water year 2003, and sand concentrations at the South Yuba River (11417500) gage were typically higher than those at the Middle Yuba River (11410000) gage for a given streamflow throughout the three year project period. Factors contributing to differences in sediment loads and grain-size distributions at the Middle Yuba River (11410000) and South Yuba River (11417500) gages include contributing drainage area, flow diversions, and deposition of bed-material-sized sediment in reservoirs upstream of the Middle Yuba River (11410000) gage. Owing to its larger drainage area, higher flows, and absence of man-made structures that restrict sediment movement in the lower basin, the South Yuba River transports a greater and coarser sediment load.

Scientific Investigations Report↗