Geology topics

Research about South Dakota

Source-linked reports with geographic coverage including South Dakota.

At least 73 records · Page 4Linked to original sources

USGS2020

Stormwater quality of infrastructure elements in Rapid City, South Dakota, 2016–18

As runoff flows over the land or impervious surfaces (paved streets, parking lots, and building roofs), it accumulates debris, chemicals, sediment, and other contaminants that can adversely affect water quality if the runoff discharge remains untreated. Pathogens, commonly measured using fecal indicator bacteria such as Escherichia coli , enterococci, or fecal coliform, are the most-frequent cause of water-quality impairment in rivers and streams in the United States. Rapid Creek originates in the western Black Hills area and flows east through Rapid City, South Dakota, to its mouth at the Cheyenne River. The water quality of Rapid Creek is important because the reach that flows through Rapid City is a valuable spawning area for a self-sustaining trout fishery, is actively used for recreation, and is a seasonal municipal water supply for the City of Rapid City. These uses (fishery, recreation, and water supply) are considered beneficial uses by the South Dakota Department of Environment and Natural Resources. Numerical criteria have been established for total suspended solids and Escherichia coli concentrations, among other water-quality constituents, for these beneficial uses. The objectives of this study were to improve the method by which fecal indicator bacteria and total suspended solids are quantified in the urban drainages within Rapid City and to provide information that helps identify origins of fecal indicator bacteria and total suspended solids. This information can be used in hydrologic models to estimate fecal indicator bacteria and total suspended solid loading from certain infrastructure elements in urban environments. Stormwater samples analyzed for Escherichia coli , total suspended solids, specific conductance, and pH were collected in three drainage basin flowpaths within Rapid City: Jackson, Wildwood, and the Eco Prayer Park. Data-collection activities for this study focused on upgradient urban flowpath elements during rainfall events. This approach builds upon previous stormwater assessments that characterized the water quality in urban basin outlets near the downstream end of the stormwater flowpaths. Within each flowpath group, 4–6 sites were selected to represent the various infrastructure elements of the runoff process. These elements included roof downspouts, parking lots, street curbs and gutters, open channels, underground storm sewers, and stormwater ponds or best-management practice facilities. In general, the concentrations of Escherichia coli and total suspended solids increased in the downstream direction for all flowpath sites. The wash-off process after the first flush is evident for total suspended solids and specific conductance; however, Escherichia coli concentrations did not necessarily follow the same pattern. Escherichia coli concentrations in the latter part of the runoff period were similar to or greater than the initial concentrations of the first set of samples. Stormwater-quality data were summarized by infrastructure type (roof downspout, parking lot, street curb, and channel/storm sewer) to provide information about approximate water-quality concentrations originating at the upper end of urban flowpaths. Escherichia coli and total suspended solid concentrations were lowest in samples collected from locations most isolated from human influence (roof downspouts); the median concentrations at these sites were 4 most probable number per 100 milliliters and 15 milligrams per liter, respectively. The delivery potential of fecal indicator bacteria and sediment from parking lots and street curbs was similar; median concentrations of Escherichia coli and total suspended solids were around 150–220 most probable number per 100 milliliters and 56–86 milligrams per liter, respectively. The downstream receiving channels and storm sewers where stormwater was aggregated typically contained the highest Escherichia coli concentrations (median was 1,800 most probable number per 100 milliliters), but the total suspended solid concentrations were similar to upstream elements in the flowpath (median was 69 milligrams per liter). The data collected from this study demonstrate that stormwater is contaminated with fecal indicator bacteria upon initial contact with impervious surfaces and highlight the importance of controlling the volume of stormwater discharges into receiving waterbodies via storage structures and pervious elements. Diluting stormwater with high concentrations of Escherichia coli with the receiving water’s (Rapid Creek) lower concentration of Escherichia coli is likely the primary mechanism for meeting the beneficial-use criterion threshold of 235 most probable number per 100 milliliters. Although total suspended solid concentrations in the upper parts of the basin (parking lots and street curbs) also begin at concentrations (56 to 86 milligrams per liter) above the beneficial-use criterion for Rapid Creek (53 milligrams per liter), current stormwater-control practices (storage ponds, swales, and wetlands) may be able to reduce suspended-sediment concentrations to meet this threshold.

South Dakota↗

USGS2020

Availability and timing of fathead minnow supplementation influence largemouth bass survival and production in rearing ponds

Adjustments to rearing practices should be justified with increases in production, stocking success, or angler satisfaction. Largemouth bass (Micropterus salmoides) production was assessed between hatchery ponds where fish were restricted to an invertebrate diet or received supplemental fathead minnow ( Pimephales promelas ) forage during 2015. At harvest, age-0 bass yield was 4.5 times greater and average fish length was 38 mm longer, in the pond that received fathead minnow. In 2016, a second study evaluated the timing of minnow supplementation that included earlier stockings of small fathead minnow (< 30 mm) compared to delayed supplementation with larger (> 30 mm) minnows. With earlier supplementation, bass yield was 2.3 times greater and fish averaged 14 mm longer at harvest. Bass survival was approximately 38% higher during 2015 when supplementation occurred and 25% higher during 2016 when minnow supplementation began earlier. Our findings show invertebrate forage was probably limiting bass production in hatchery ponds and supplementing with appropriately-sized fathead minnows increased age-0, largemouth bass production.

South Dakota↗

USGS2020

Effect of environmental factors on the movement of Rainbow Trout in the Deerfield Reservoir System

Spawning movements and the factors affecting those movements are often of interest to fisheries managers and biologists. The objective of this study was to examine the influence of environmental factors on the movements of an adfluvial Rainbow Trout Oncorhynchus mykiss population in the Black Hills, South Dakota. Three unique strains of hatchery-reared Rainbow Trout and resident Rainbow Trout were implanted with passive integrated transponder (PIT) tags and movements between Deerfield Reservoir and the Castle Creek tributary system were monitored from August, 2010-July, 2011. Initial adfluvial movements of Rainbow Trout were detected using a stationary PIT tag reader deployed near the mouth of Castle Creek. Multiple linear regressions were used to model the relationship between PIT tagged Rainbow Trout movement and water temperature, photoperiod, and discharge. Using Akaike’s information criterion (AIC) to compare models, discharge was the top supported model explaining variation in Rainbow Trout movement. Additionally, models containing temperature and photoperiod were also supported. Supported models only explained moderate levels of variation (<23%) in Rainbow Trout movement. Understanding how environmental variables affect the movement patterns of this unique population is essential in determining the proper management strategy for the Deerfield Reservoir system.

South Dakota↗

USGS2019

Groundwater characterization of the Madison aquifer near Jewel Cave National Monument, South Dakota

Jewel Cave National Monument in the Black Hills of southwestern South Dakota has more than 200 miles of mapped cave passages and several subterranean lakes that have been discovered since 2015. Jewel Cave is one of the world’s longest known caves and its natural beauty and unique natural cave features led U.S. President Theodore Roosevelt to designate the cave as a national monument in 1908. Jewel Cave was naturally formed in the regionally extensive Madison Limestone, which is characterized as a carbonate karst environment (containing caves and sinkholes) with extensive subterranean cave networks and losing streams at the land surface. Preserving and protecting the cave is an important element of the National Park Service mission, and understanding the hydrogeologic connection between the surface and the subsurface is essential for ensuring the preservation and protection of the cave for future generations. A component in preserving and protecting the park includes the improved understanding of groundwater flow and vulnerability of the subsurface, which allows scientists, park managers, the visiting public, and the surrounding communities to better manage, protect, and preserve the site and its unique natural features.

South Dakota↗

USGS2019

Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota

The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux aquifer in the model area. The model area includes the Big Sioux aquifer and the underlying hydrogeologic units from Dell Rapids, South Dakota, to the confluence of the Big Sioux River and the outlet of the Sioux Falls Diversion Channel in eastern Sioux Falls, S. Dak. The Big Sioux aquifer is the primary aquifer in the model area and the focus of the groundwater-flow model. The Big Sioux River is the largest stream in the model area and is in hydraulic connection with the Big Sioux aquifer. A conceptual model for the area was constructed and includes a characterization of the hydrogeologic framework, analysis and construction of potentiometric surfaces, and summary of estimated water budget components in the model area. The primary hydrogeologic units in the model area consist of (1) the Big Sioux aquifer, (2) a glacial till confining unit, and (3) bedrock aquifers (Split Rock Creek and Sioux Quartzite aquifers). Sources of groundwater recharge included infiltration of precipitation, stream seepage, and groundwater exchanges among the hydraulically connected Big Sioux aquifer, glacial till confining unit, and bedrock aquifers. Groundwater losses included evapotranspiration, groundwater discharge to streams, and groundwater withdrawal to supply water-use needs. A numerical groundwater-flow model (numerical model) was constructed and was used to simulate all aspects of the conceptual model for predevelopment (steady-state) and time-varying (transient) monthly conditions for 1950–2017. The numerical model was constructed using the USGS modular hydrologic simulation program, MODFLOW–6, and was calibrated using the Parameter ESTimation software, PEST++. The transient numerical model was calibrated for steady-state and transient monthly conditions for 1950–2017. Calibration targets were observations of hydraulic head, changes in hydraulic head, monthly mean streamflow (as a rate), and cumulative monthly stream discharge (as a volume). Parameters adjusted during model calibration were horizontal and vertical hydraulic conductivity, specific storage, specific yield, recharge and evapotranspiration multipliers, and streambed hydraulic conductivity. Horizontal and vertical hydraulic conductivity were estimated at pilot points distributed within the model area; specific storage and specific yield were assigned to uniform values in each layer in the model area; recharge and evapotranspiration multipliers were assigned uniformly for every stress period in the numerical model; and streambed hydraulic conductivity values were assigned uniformly between stream confluences. The final calibrated parameter values of horizontal and vertical hydraulic conductivity, specific yield, specific storage, streambed hydraulic conductivity, recharge, and evapotranspiration were considered reasonable for the hydrogeologic materials and conditions in the model area for 1950–2017. Overall, simulated hydraulic head altitudes had a linear regression coefficient of determination (R 2 ) of 0.48. Hydraulic head altitude residuals for the glacial till confining unit and bedrock aquifers were typically greater in magnitude when compared to residuals in the Big Sioux aquifer, but simulated hydraulic head altitudes in the Big Sioux aquifer compared favorably with mean observed hydraulic head altitudes and had a linear regression R 2 of 0.93. Simulated streamflow hydrographs matched the general trends of observed increases and decreases in streamflow for USGS streamgages 06482000 (Big Sioux River at Sioux Falls, S. Dak.) and 06482020 (Big Sioux River at North Cliff Avenue at Sioux Falls, S. Dak.), but larger streamflows were overestimated at the first streamgage and underestimated at the second streamgage. The numerical model reasonably estimated cumulative monthly stream discharge for the first 10–15 years of available streamflow records at both USGS streamgages. After the first 10–15 years of available streamflow record, cumulative monthly stream discharge was closely estimated for USGS streamgage 06482000 and underestimated at USGS streamgage 06482020. Composite sensitivities without regularization were calculated by PEST++ for the calibrated numerical model parameters and were averaged by parameter group. The parameter group with the highest mean composite sensitivity was the recharge multiplier parameter group. Model simplifications, assumptions, and limitations were necessary for construction of the conceptual and numerical models and for calibration efficiency. Spatial simplification of hydraulic properties could cause the numerical model to misrepresent reactions to changes in localized stresses, such as additional demands for groundwater withdrawal. The numerical model was temporally discretized into monthly periods and required scaling daily rates into representative monthly rates for model input and calibration targets. Based on the comparison between the observed and simulated groundwater levels, monthly mean streamflow and cumulative monthly stream discharge, and general groundwater distribution and flow, the numerical model favorably simulated the flow in the Big Sioux aquifer. Eventual capture was calculated in the model area using a steady-state numerical groundwater-flow model. The eventual capture map shows areas of higher streamflow capture adjacent to the Big Sioux River north of the city of Sioux Falls and along the lower part of the Sioux Falls Diversion Channel, and areas of lower streamflow capture along aquifer boundaries and near the southern Sioux Quartzite barrier. The timing of capture was determined using a transient numerical groundwater-flow model to determine the likely captured water sources for 30 years of groundwater withdrawal at three hypothetical wells using three continuous withdrawal rates (112.5, 450.0, and 900.0 gallons per minute). Supply for all three hypothetical wells became capture-dominated after only a short period of continuous withdrawal. Capture stabilized after about 10–15 years for well A, and after 20–25 years for well B, and after about 10–15 years for well C. The groundwater-flow model is a suitable tool to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux aquifer near Sioux Falls, S. Dak. The numerical model can be used to simulate hydrologic scenarios, advance understanding of groundwater budgets, compute system response to stress, and determine likely sources of water supplied to wells.

South Dakota↗

USGS2019

300,000 yr history of water-table fluctuations at Wind Cave, South Dakota, USA—Scale, timing, and groundwater mixing in the Madison Aquifer

Deposits of calcite coating the lower passages of Wind Cave in the southern Black Hills of South Dakota were precipitated under phreatic conditions. Data from samples associated with a new cave survey and hydrologic studies indicate that past water tables within Wind Cave reached a maximum height of 45 m above modern levels but were mostly confined to 25 m or less. Uranium-series ages for basal layers deposited on weathered wall rock indicate subaerial conditions in this part of the cave persisted between 1000 and 300 ka. Ages and elevations of wall coatings and cave rafts establish a 300,000 yr paleohydrograph indicating that water-table highstands occurred during interglacial or interstadial-to-early glacial periods and lowstands occurred during full-glacial and stadial episodes. Isotopes of Sr, U, C, and O from dated calcite samples were obtained to evaluate potential shifts in paleo-groundwater composition. For comparison, Sr and U isotopic compositions were determined for modern groundwater from 18 sites previously classified into five hydrogeologic domains. Isotope data for different domains tend to cluster in separate fields, although several fields overlap. Compositions of Calcite Lake (informal name) water reflect modern recharge to shallow aquifers. In contrast, speleothem data indicate that paleo-groundwater highstands were not supported by increased infiltration associated with local recharge, or by upwelling from deeper Proterozoic sources. Instead, cave water was similar to deeper, warmer groundwater from the Madison Aquifer discharging at modern artesian springs flanking the southern Black Hills. Highstands were likely influenced by large-scale hydraulic processes associated with recharge to the Madison Aquifer under the Laurentide ice sheet on the northeast side of the Williston Basin, causing increased hydrostatic pressures in confined aquifers on the south side of the basin.

South Dakota↗

USGS2019

Generalized potentiometric-surface map and groundwater flow directions in the Madison aquifer near Jewel Cave National Monument, South Dakota

A generalized potentiometric-surface map of the Madison aquifer near Jewel Cave National Monument was constructed using water levels measured from calendar years 1988 to 2019 in 24 groundwater wells and 4 subterranean cave lakes interpreted to be in hydraulic connection with the aquifer. The map indicated that groundwater near Jewel Cave National Monument originates from recharge sources to the Madison aquifer in the higher elevations in the north-central area of the map, flows west to south-southwest through the Jewel Cave network, then southeast. Hydrographs were constructed using water levels from four observation wells and one subterranean lake (Hourglass Lake) in the Jewel Cave network to evaluate historical and current groundwater recharge to the Madison aquifer in the study area. Hydrographs from 1992 through 2018 indicated water levels were lowest from the early to mid-1990s, increased through the late 1990s, peaked in the early 2000s, decreased until 2010, and then increased to the highest levels during 2016–18. A visual comparison of the Hourglass Lake hydrograph with cumulative precipitation, and quantitative (statistical) comparison of lake-water levels with cumulative precipitation, indicated that lake-water levels increased as cumulative precipitation increased, most likely due to some degree of precipitation recharge to hydraulically connected Madison Limestone outcrops. Comparing the potentiometric-surface map constructed for this study, with a map by Strobel and others (2000) of the same region and aquifer, indicated similarity and, therefore, provided some validation of map construction. The potentiometric-surface map constructed for this study could be used by park managers and others as a tool to evaluate the hydrogeologic characteristics of the Madison aquifer in the study area.

South Dakota↗

USGS2019

Influence of season, sex, age and diet composition on mercury concentration in Walleye Sander vitreus

We collected Walleye Sander vitreus (May–October) from Bitter and Twin lakes, South Dakota to assess seasonal- and diet-related variation in tissue mercury (Hg) concentration. The average Hg concentration in Walleye was 43–68% higher in the spring for Bitter ( p < 0.008) and Twin Lakes ( p < 0.017) compared with summer or autumn months. Bioenergetics analysis of Bitter Lake Walleye showed that consumption of fish prey (primarily Fathead Minnow Pimephales promelas ) increased from late summer through winter and was linked to increased Hg accumulation in Walleye the following spring. Mercury concentration varied significantly with Walleye age but was similar for comparably-aged male (0.62 μg/g) and female fish (0.62 μg/g). However, after adjusting for Walleye size (total length, mm), mean Hg concentration was greater in male (0.66 μg/g) compared with female (0.50 μg/g) fish, likely due to slower growth rate of male Walleye. At 425 mm, male Walleye in Bitter Lake were approximately 1 year older than female fish. These findings show that diet, age, and gender-related growth affect Hg concentration in Walleye and are important factors to consider in fish contaminant monitoring programs.

South Dakota↗

USGS2019

Economic activity generated by angling at small South Dakota lakes

Many agencies overlook the values affiliated with relatively small fisheries throughout their jurisdictions. The economic activity associated with angling visits to seven small fisheries in South Dakota was estimated using IMPLAN software. The average economic activity associated with fishing at individual lakes in 2016 was US\$35,369/lake, which was estimated to support an average of 0.48 jobs and create \$5,572 in tax revenues. We observed that lakes with the highest proportions of ice fishing pressure also had the greatest associated economic activity, even though several of these had the lowest overall fishing pressure throughout the year. In addition to economic activity, the zone of influence for each lake was estimated and compared with the proximity to urban centers. The inclusion of economic information from small fisheries may play an important role in influencing key strategic planning efforts by management agencies and in estimating the overall economic importance of angling on broader scales.

South Dakota↗

USGS2019

Hydraulic conductivity estimates from slug tests in the Big Sioux aquifer near Sioux Falls, South Dakota

Hydraulic conductivity estimates were made for 15 observation wells using slug-out (rising-head) tests in the Big Sioux aquifer near Sioux Falls, South Dakota, as part of a cooperative study with the City of Sioux Falls to characterize the hydrogeology and the extent of the Big Sioux aquifer north of the city. Well and aquifer data were collected from field measurements and drillers’ logs. Multiple slug tests were completed at each observation well with a transducer to record the change in water level and a U.S. Geological Survey standard mechanical slug to displace the well’s water column. In total, 110 slug-out test trials were completed among the 15 observation wells. Hydraulic conductivity was estimated by curve fitting with AQTESOLV Pro version 4.50.002. Hydraulic conductivity estimates ranged from 64 to 379 feet per day (ft/d). The mean, standard deviation, and median hydraulic conductivity for the 110 slug-out test trials were 171 ft/d, 73 ft/d, and 157 ft/d, respectively. The mean hydraulic conductivity calculated for each well ranged from 88 to 270 ft/d, the standard deviation ranged from 7 to 66 ft/d, and the median hydraulic conductivity ranged from 86 to 256 ft/d.

South Dakota↗

USGS2019

Comparison of aquatic invertebrate communities in near-shore areas with high or low boating activity

Lakeshore areas provide important habitat for aquatic invertebrates in shallow lakes. However, these zones are prone to anthropogenic disturbances that include shoreline development, urbanization, nutrient inputs, agricultural and(or) recreational use. Among recreational uses, public access sites are often developed to accommodate boaters and facilitate lake access via boat ramps. Although the ‘foot print’ associated with boat ramp structures can be relatively small compared to total shoreline coverage, little is known about the relative effects of boating activity on littoral zones and macroinvertebrate communities. In this study, we assess the relative impact of boating-related activities on aquatic macroinvertebrate communities at high-use (primary) and low-use (secondary) boat ramps on five glacial lakes of eastern South Dakota. Macroinvertebrate assemblages were dominated by few taxa that included Chironomidae, Corixidae, Caenidae, and Amphipoda. Moreover, boat ramp use did not influence abundance or diversity of aquatic macroinvertebrates. Habitat, specifically substrate composition, was also similar between primary and secondary boat ramps despite more intense use associated with primary boat ramps. Our results support related findings that aquatic invertebrate assemblages in the Prairie Pothole Region are structured by regional environmental variability (climate, habitat, and water quality) resulting in communities with characteristically low diversity and tolerant taxa. This may explain why small-scale disturbance associated with boating activity has no discernable effect on macroinvertebrate assemblages in glacial lakes of the Prairie Pothole Region.

South Dakota↗

USGS2019

Evaluation of five pulicides to suppress fleas on black-tailed prairie dogs: Encouraging long-term results with systemic 0.005% fipronil

Plague, a flea-borne disease, hampers efforts to restore populations of black-footed ferrets ( Mustela nigripes ), which occupy colonies of prairie dogs ( Cynomys spp.) in North America. Plague is managed by infusing prairie dog burrows with DeltaDust ® 0.05% deltamethrin, a pulicide that kills fleas. Experiments are needed to identify pulicides that can be used in rotation with DeltaDust for integrated plague management. In South Dakota, USA, we tested the efficacy of four pulicide dusts when applied at a rate of 8 g per burrow on colonies of black-tailed prairie dogs ( Cynomys ludovicianus ): Sevin ® 5% carbaryl; Dusta-cide ® 6% malathion; Alpine ® 0.25% dinotefuran with 95% diatomaceous earth; and Tri-Die ® 1% pyrethrum with 40% amorphous silica and 10% piperonyl butoxide. We also tested systemic 0.005% fipronil, which was distributed as ½ cup of laced grain per burrow. We sampled prairie dogs on 3294 occasions and detected 10,041 fleas. Sevin and Dusta-cide suppressed fleas but only for 1 month. Neither Alpine nor Tri-Die had any noticeable, consistent effect on fleas. Fipronil suppressed fleas by 97–100% for 3 months. The residual effect of fipronil persisted for ∼12 months. Efficacy of fipronil seems comparable with DeltaDust, which exhibited a residual effect for ∼10 months in prior studies. Continued research is needed to optimize fipronil treatments for plague management on prairie dog colonies.

South Dakota↗

USGS2019

Extreme climatic variability during migration invokes physiological and dietary plasticity among spring migrating ducks

Environmental stochasticity encountered during migration can have negative consequences for individuals and population demographics through direct reductions in survival or cross-seasonal impacts. We took advantage of substantial interannual variation in spring migration conditions over a 4 year field study to examine physiological and dietary variation among two species of migrant ducks. We collected female Lesser Scaup ( Aythya affinis (Eyton, 1838)) and Blue-winged Teal ( Spatula discors (Linnaeus, 1766)) during spring migration and measured lipid and protein reserves, an index of recent lipid metabolism based on concentrations of lipid metabolites in plasma, and diets. We documented systematic interannual variation among these metrics in both species, contrasting primarily the warmest, earliest spring and the coldest, latest spring. Lesser Scaup had reduced lipid and protein reserves and consumed less energy-rich prey during the coldest and latest spring but showed no interannual variation in the index of lipid metabolism. Blue-winged Teal similarly had reduced protein reserves in the cold, late spring but maintained constant lipid reserves among years, likely facilitated by increased consumption of energy-rich seeds reflected in diets and lipid metabolism. Our results reveal impacts of environmental stochasticity on migrants and suggest that recruitment may be impacted by variable conditions encountered during migration during extreme weather events.

South Dakota↗

USGS2019

Application strategy for an anthraquinone-based repellent and the protection of soybeans from Canada goose depredation

Agricultural crops can sustain extensive damage caused by Canada geese ( Branta canadensis ) when these crops are planted near wetlands or brood-rearing sites. From 2000 to 2015, South Dakota Game, Fish and Parks spent >$5.6 million to manage damages caused by Canada geese to agricultural crops (primarily soybeans) in South Dakota, USA. For the purpose of developing a repellent application strategy for nonlethal goose damage management, we comparatively evaluated the width of anthraquinone applications (i.e., 9.4 L Flight Control ® Plus goose repellent/ha [active ingredient: 50% 9,10-anthraquinone] at 0–36 m versus 0–73 m perpendicular to the edge of wetlands in 2014), the timing of the first repellent application (i.e., 9.4 L Flight Control Plus goose repellent/ha at 50% versus 75% seedling emergence in 2015), the yield of soybeans ( Glycine max ) within repellent-treated and untreated subplots, and anthraquinone chemical residues in Day County, South Dakota. Soybean yield was greater in subplots 73 m from the water’s edge than that in the 36-m subplots ( P < 0.02). Among subplots first sprayed at 50% seedling emergence, soybean yield was greater at 73 m and 82 m than that at 36 m ( P < 0.005). In contrast, we observed no difference in yield at 36 m, 73 m, or 82 m in the subplots first sprayed at 72% seedling emergence ( P > 0.09). We therefore conclude that goose damages were effectively managed in subplots first sprayed at 72% seedling emergence. Anthraquinone residues averaged 674 and 629 ppm anthraquinone upon the first application of the repellent (June to July), 22 and 35 ppm anthraquinone in the mid-season hay (August to September), and 36 and 28 ppb anthraquinone in the harvested seed (October to November) in 2014 and 2015, respectively. Our results suggest that a 73-m bandwidth of anthraquinone-based repellents first applied at approximately 72% or 65–85% seedling emergence can protect soybeans from Canada goose depredation.

South Dakota↗

USGS2019

Evaluation of an elk detection probability model in the Black Hills, South Dakota

Since 1993, elk ( Cervus canadensis nelsoni ) abundance in the Black Hills of South Dakota has been estimated using a detection probability model previously developed in Idaho, though it is likely biased because of a failure to account for visibility biases under local conditions. To correct for this bias, we evaluated the current detection probability across the Black Hills during January and February 2009–2011 using radio-collared elk. We used logistic regression to evaluate topographic features, habitat characteristics, and group characteristics relative to their influence on detection probability of elk. Elk detection probability increased with less vegetation cover (%), increased group size, and more snow cover (%); overall detection probability was 0.60 (95% CI 0.52–0.68), with 91 of 152 elk groups detected. Predictive capability of the selected model was excellent (ROC = 0.807), and prediction accuracy ranged from 70.2% to 73.7%. Cross-validation of the selected model with other population estimation methods resulted in comparable estimates. Future applications of our model should be applied cautiously if characteristics of the area (e.g., vegetation cover >50%, snow cover >90%, group sizes >16 elk) differ notably from the range of variability in these factors under which the model was developed.

South Dakota↗

USGS2019

Implications of climate scenarios for Badlands National Park resource management

Badlands National Park (BADL) hosts a myriad of natural and cultural resources, including bison and black-footed ferrets, the mixed grass prairie they live in, 37-75 million-year-old fossils, and historic buildings, trails, and roads. All are sensitive to climate, but anticipating precisely how each will be affected by climate change is difficult. In the face of this challenge, park resource managers must nevertheless make forward-looking decisions and take action to meet resource management goals. Fortunately, tools exist to identify strategies and actions likely to succeed under a range of potential future climate conditions. Two such tools—qualitative scenario planning and quantitative ecological simulation modeling—were used to anticipate management challenges and identify solutions for BADL and adjacent federal and tribal lands in the coming decades (through 2050). This brief summarizes and synthesizes results of this work. Although the brief focuses on BADL, it also includes several key insights gained from examining management approaches on adjacent lands.

South Dakota↗

USGS2019

Multivariate analysis of hydrochemical data for Jewel Cave, Wind Cave, and surrounding areas

Jewel Cave National Monument and Wind Cave National Park in South Dakota contain two of the six longest caves worldwide. These caves contain subterranean lakes that are important points of intersection between the water table of the Madison aquifer and the caves. During 2015 to 2017, several subterranean lakes were discovered in Jewel Cave, which previously was thought to be above the regional water table. The objectives of this study were to better understand the hydrology of the recently discovered lakes in Jewel Cave and to evaluate their relation or possible connection to similar subterranean lakes in Wind Cave. Both objectives align with National Park Service resource management purposes. Multivariate analysis, consisting of principal component analysis (PCA), cluster analysis, and end member mixing, was applied to hydrochemical data for 70 sites within and surrounding Jewel Cave and Wind Cave. Hydrochemical data consisted of the contents of major ions (Ca, Mg, Na, HCO3, Cl, Si, SO4), arsenic (As), strontium (Sr), uranium (U), stable isotopes of oxygen and hydrogen (δ18O, δ2H), radiogenic isotope ratios of strontium and uranium (87Sr/86Sr and 234U/238U), pH, and electrical conductivity (EC) in water samples. Five hydrogeologic domains were identified on the basis of PCA and cluster analysis for the area encompassing Jewel Cave and Wind Cave in the southern Black Hills. The Artesian 1 and Artesian 2 domains represent primarily artesian springs and surrounding groundwater, the East and West domains represent areas where Madison and Minnelusa aquifer rocks are at or near the land surface, and the Precambrian domain represents the Precambrian aquifer. Multivariate analysis indicates that the Jewel Cave area is part of the West domain and that Wind Cave is part of the East domain. End member mixing was applied to estimate that groundwater in the Jewel Cave area primarily was derived from the West domain and secondarily from the Precambrian domain. Jewel Cave and Wind Cave contain lakes that are well connected to regional groundwater flow in the Madison aquifer.

South Dakota↗

USGS2018

Revised groundwater-flow model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015

The city of Aberdeen, in northeastern South Dakota, requires an expanded and sustainable supply of water to meet current and future demands. Conceptual and numerical models of the glacial aquifer system in the area north of Aberdeen were developed by the U.S. Geological Survey in cooperation with the City of Aberdeen in 2012. The U.S. Geological Survey, in cooperation with the City of Aberdeen, completed a study to revise the original numerical groundwater-flow model using data through water year (WY) 2015 to aid the City of Aberdeen in their development of plans and strategies for a sustainable water supply and to increase understanding of the glacial aquifer system and groundwater-flow system near Aberdeen. The original model was revised to improve the fit between model-simulated values and observed (measured or estimated) data, provide greater insight into surface-water interactions, and improve the usefulness of the model for water-supply planning. The revised groundwater-flow model (hereafter referred to as the “revised model”) presented in this report supersedes the original model. The purpose of this report is to describe a revised groundwater-flow model including data collection, model calibration, and model results for the glacial aquifer system including the Elm, Middle James, and Deep James aquifers north of Aberdeen, South Dakota, using updated hydrologic data through WY 2015. The original numerical model was revised in several ways. The model was modified by adding four new layers, which included a surficial layer, two intervening confining layers, and a shale bedrock layer. The revised model provides an improved understanding of the groundwater-flow system in comparison to the original model. The principal aquifers of the model area include portions of the Elm, Middle James, and Deep James aquifers. The lithologic information used to define and describe the aquifers in the model area was unaltered; however, aquifer properties and boundary conditions were reviewed and updated using geological information reported by the South Dakota Department of Environmental and Natural Resources and information obtained from geophysical investigations for this study. The horizontal extent of the Elm, Middle James, and Deep James aquifers was unaltered from the original model. The thickness of the Deep James aquifer was modified based on interpretations from the geophysical investigations. In general, groundwater in the Elm aquifer flowed from northwest to southeast and locally towards rivers and streams. Similarly, in the Middle James and Deep James aquifers, groundwater also typically flowed southeast. The revisions made to the original model include use of the following MODFLOW stress packages: Recharge, Evapotranspiration, Time-Variant Specified Head, Wells, Drains, and Stream Flow Routing, all of which were updated from the original model except for the Stream Flow Routing Package, which replaced the River Package used in the original model. Model calibration is the process of estimating model parameters to minimize the differences, or residuals, between observed data and simulated values; therefore, Parameter ESTimation (PEST) software was used to optimize model input parameters by matching model-simulated values to observed data. Calibration parameters included horizontal hydraulic conductivity, vertical hydraulic conductivity, specific yield, specific storage, and vertical streambed conductance for stream and drain cells. Multipliers were used to calibrate the recharge and evapotranspiration stresses. Evapotranspiration extinction depth also was adjusted during model calibration. Comparisons to the original model are described to highlight the changes made in the revised model. In general, the revised model adequately simulates the natural system and compares favorably with observed hydrologic data. Simulated water levels were evaluated by comparing them to single water-level observations at selected well locations. The selected wells were the same wells used in the original model. The coefficient of determination value between simulated and observed water levels for the revised model was 0.89 and included simulated and observed values from October 1, 1974 (WY 1975), through September 30, 2015 (WY 2015). The coefficient of determination value for the original model was 0.94 and included simulated and observed values from October 1, 1974, through September 30, 2009. The difference may indicate that the original model could have been overfit to hydraulic head observations because base flow was not simulated. The additional data used in the revised model included some climatically wetter, more extreme periods, such as 2011, in which annual precipitation was 30.9 inches. Average annual precipitation for the original model timeframe, which included data from WYs 1975–2009, was 20.26 inches. Additional precipitation data for WYs 2010–15, included in the revised model timeframe, resulted in an average annual precipitation for WYs 1975–2015 in the model area of 20.6 inches. The larger variability in climate data coupled with the additional water-level data could explain the lower coefficient of determination for water levels in the revised model. The revised model was used to calculate various groundwater-budget components for steady-state and transient conditions for WYs 1975–2015. The time-variant specified-head cells in the revised model had the largest change when compared to the original steady-state model for inflows and outflows. Comparing the transient budget components between the original and the revised models indicated that inflow from recharge and time-variant specified-head cells had the greatest effect on groundwater inflows, and outflow from storage had the greatest effect on groundwater outflows. The simulated potentiometric contours from the revised model were compared with (1) the observed (interpreted) potentiometric surface (layer 2) and the hydraulic head values (layers 4 and 6) and (2) the simulated contours from the original model. The simulated hydraulic gradients and general direction of groundwater flow in the Elm aquifer in the revised model generally matched the observed potentiometric contours, the simulated potentiometric contours from the original model, and general flow directions interpreted to be perpendicular to the contours. Minor discrepancies between simulated potentiometric contours from the revised model and the observed potentiometric contours may be due to the lack of observed data in the model area. The revised model was designed to reduce the limitations of the original model. The revisions were validated by comparing the results of the original model with the revised model. A primary benefit of the revised model is the inclusion of the surficial deposits and the confining units as explicit layers in the model. The addition of the surficial layer was beneficial for three primary reasons: (1) more accurate representation of recharge from precipitation, (2) more accurate representation of groundwater evapotranspiration, and (3) more accurate representation of groundwater and surface-water interactions. The groundwater model is a numeric approximation of a complex physical hydrologic system, and the revised model data were interpolated in regions with sparse data. Additionally, model discretization included averaged and interpolated values for water use, withdrawal rates, and hydraulic conductivity. The revised model provides a useful estimate for hydraulic gradients, groundwater-flow directions, and aquifer response to groundwater withdrawals.

South Dakota↗