Oceanography and Atmospheric Sciences and Meteorology Commons^™

Assessing The Evolution Of Soil Moisture And Vegetation Conditions During A Flash Drought–Flash Recovery Sequence Over The South-Central United States, Jason A. Otkin, Yafang Zhong, Eric D. Hunt, Jeff Basara, Mark Svoboda, Martha C. Anderson, Christopher Hain

National Drought Mitigation Center: Faculty Publications

This study examines the evolution of soil moisture, evapotranspiration, vegetation, and atmospheric conditions during an unusual flash drought–flash recovery sequence that occurred across the south-central United States during 2015. This event was characterized by a period of rapid drought intensification (flash drought) during late summer that was terminated by heavy rainfall at the end of October that eliminated the extreme drought conditions over a 2-week period (flash recovery). A detailed analysis was performed using time series of environmental variables derived from meteorological, remote sensing, and land surface modeling datasets. Though the analysis revealed a similar progression of cascading effects in …

Soil Moisture Monitoring Using Remote Sensing Data And A Stepwise-Cluster Prediction Model: The Case Of Upper Blue Nile Basin, Ethiopia, Getachew Ayehu, Tsegaye Tadesse, Berhan Gessesse, Yibeltal Yigrem

National Drought Mitigation Center: Faculty Publications

In this study, a residual soil moisture prediction model was developed using the stepwise cluster analysis (SCA) and model prediction approach in the Upper Blue Nile basin. The SCA has the advantage of capturing the nonlinear relationships between remote sensing variables and volumetric soil moisture. The principle of SCA is to generate a set of prediction cluster trees based on a series of cutting and merging process according to a given statistical criterion. The proposed model incorporates the combinations of dual-polarized Sentinel-1 SAR data, normalized difference vegetation index (NDVI), and digital elevation model as input parameters. In this regard, two …

Socioecological Determinants Of Drought Impacts And Coping Strategies For Ranching Operations In The Great Plains, Tonya Haigh, Walter H. Schacht, Cody L. Knutson, Alexander J. Smart, Jerry Volesky, Craig R. Allen, Michael Hayes, Mark E. Burbach

National Drought Mitigation Center: Faculty Publications

In Great Plains rangelands, drought is a recurring disturbance. Ranchers in this region expect to encounter drought but may not be adequately prepared for it. Efforts to encourage drought preparednesswould benefit froma better understanding of the conditions under which managers make decisions to minimize the impacts of drought.We tested the direct andmoderating roles of the drought hazard and the social-ecological context on drought impacts and response. This study was conducted with ranchers in western and central South Dakota and Nebraska following the drought that began in 2012. We surveyed ranchers regarding the effects of the drought and their responses and …

Irrigation Water Quality—A Contemporary Perspective, Arindam Malakar, Daniel D. Snow, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

In the race to enhance agricultural productivity, irrigation will become more dependent on poorly characterized and virtually unmonitored sources of water. Increased use of irrigation water has led to impaired water and soil quality in many areas. Historically, soil salinization and reduced crop productivity have been the primary focus of irrigation water quality. Recently, there is increasing evidence for the occurrence of geogenic contaminants in water. The appearance of trace elements and an increase in the use of wastewater has highlighted the vulnerability and complexities of the composition of irrigation water and its role in ensuring proper crop growth, and …

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- January 2019, Natalie Umphlett, Rezaul Mamood, Warren Pettee, Gannon Rush, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the director........................................1

Staff spotlight...........................1

Year in review............................2

Drought THIRA toolkit...........3

Product highlight....................4

Update on regional climate conditions..................................4

Other HPRCC news.................5

Recent and upcoming travel and activities.............................6

The Evolution, Propagation, And Spread Of Flash Drought In The Central United States During 2012, Jeffrey B. Basara, Jordan I. Christian, Ryann A. Wakefield, Jason A. Otkin, Eric H. Hunt, David P. Brown

School of Natural Resources: Faculty Publications

During 2012, flash drought developed and subsequently expanded across large areas of the Central United States (US) with severe impacts to overall water resources and warm-season agricultural production. Recent efforts have yielded a methodology to detect and quantify flash drought occurrence and rate of intensification from climatological datasets via the standardized evaporative stress ratio (SESR). This study utilizes the North American Regional Reanalysis and applied the SESR methodology to quantify the spatial and temporal development and expansion of flash drought conditions during 2012. Critical results include the identification of the flash drought epicenter and subsequent spread of flash drought conditions …

Role Of Sea Surface Temperatures In Forcing Circulation Anomalies Driving U.S. Great Plains Pluvial Years, Paul X. Flanagan, Jeffrey B. Basara, Jason C. Furtado, Elinor R. Martin, Xiangming Xiao

High Plains Regional Climate Center: Staff Publications

In the U.S. Great Plains (GP), diagnosing precipitation variability is key in developing an understanding of the present and future availability of water in the region. Building on previous work investigating U.S. GP pluvial years, this study usesERAtwentieth century (ERA-20C) reanalysis data to investigate key circulation anomalies driving GP precipitation anomalies during a subset of GP pluvial years (called in this paper Pattern pluvial years). With previous research showing links between tropical Pacific sea surface temperature (SST) anomalies and GP climate variability, this study diagnoses the key circulation anomalies through an analysis of SSTs and their influence on the atmosphere. …

Prehistoric Chaco Canyon, New Mexico: Importation Of Meat And Mmaize, Larry V. Benson, Deanna Grimstead, John R. Stein, David A. Rith, Terry L. Plowman

United States Geological Survey: Staff Publications

In a recent paper, Benson and Grimstead (2019) determined that only minimal amounts of maize could have been grown in Chaco Canyon due to its aridity, short growing season, and frequent summer flooding of the valley floor. In this paper it is shown that deer and rabbit densities within semiarid regions such as the Canyon are such that 2300 Canyon residents would eliminate essentially all small and large mammals within a year. This implies that food (meat and maize) must have been imported from one or more outlying areas to feed the Canyon's residential population. This would have entailed ~18,000 …

Chaco Canyon, New Mexico: A Caretaker City And A Pilgrimage Destination, Larry Benson, Deanna N. Grimstead, John R. Stein, David A. Roth, Terry I. Plowman

United States Geological Survey: Staff Publications

Some Southwestern archaeologists continue to ascribe to the hypothesis that Chaco was agriculturally productive to the point that it could support at least a few thousand full-time residents. This paper suggests an alternative hypothesis; i.e., Chaco was marginally productive and could only support a few hundred permanent residents. Isotopic analysis of mammal teeth found in trenches cut through platform mounds fronting Pueblo Bonito indicate the possibility that much of the meat consumed by Chacoan residents and visitors came from higher elevation sites bordering the San Juan Basin. We suggest that resident population estimates based on great house room numbers and …

Spatial Conservation Planning Under Uncertainty: Adapting To Climate Change Risks Using Modern Portfolio Theory, Mitchell J. Eaton, Simeon Yurek, Zulqarnain Haider, Julien Martin, Fred Johnson, Bradley J. Udell, Hadi Charkhgard, Changhyun Kwon

United States Geological Survey: Staff Publications

Climate change and urban growth impact habitats, species, and ecosystem services. To buffer against global change, an established adaptation strategy is designing protected areas to increase representation and complementarity of biodiversity features. Uncertainty regarding the scale and magnitude of landscape change complicates reserve planning and exposes decision makers to the risk of failing to meet conservation goals. Conservation planning tends to treat risk as an absolute measure, ignoring the context of the management problem and risk preferences of stakeholders. Application of risk management theory to conservation emphasizes the diversification of a portfolio of assets, with the goal of reducing the …

Improved Flow Frequency Techniques With Frequency-Based Storms And Bulletin 17c, Katherine M. Werner

United States Geological Survey: Water Reports and Publications

This paper summarizes the hydrologic evaluation performed by the United States Army Corps of Engineers (USACE), Omaha District as part of the Elkhorn Basin Flood Plain Management Services (FPMS) Flood Risk Identification Study. The Elkhorn Basin FPMS Study is a collaborative effort between the Nebraska Department of Natural Resources (NeDNR), the USACE, and the Federal Emergency Management Agency (FEMA) Region VII. The Elkhorn River is located in northeastern Nebraska, covers approximately 7,000 square miles, and includes 11 Federally Constructed Levees, 5 high hazard dams, and dozens of NFIP participating communities. Previous flood risk information in the basin was developed specific …

Influence Of Land Cover And Soil Moisture Based Brown Ocean Effect On An Extreme Rainfall Event From A Louisiana Gulf Coast Tropical System, Udaysankar S. Nair, Eric Rappin, Emily Foshee, Warren Smith, Roger A. Pielke Sr., Rezaul Mahmood, Jonathan L. Case, Clay B. Blankenship, Marshall Shepherd, Joseph A. Santanello, Dev Niyogi

High Plains Regional Climate Center: Staff Publications

Extreme flooding over southern Louisiana in mid-August of 2016 resulted from an unusual tropical low that formed and intensified over land. We used numerical experiments to highlight the role of the ‘Brown Ocean’ effect (where saturated soils function similar to a warm ocean surface) on intensification and it’s modulation by land cover change. A numerical modeling experiment that successfully captured the flood event (control) was modified to alter moisture availability by converting wetlands to open water, wet croplands, and dry croplands. Storm evolution in the control experiment with wet antecedent soils most resembles tropical lows that form and intensify over …

The Total Solar Eclipse Of 2017: Meteorological Observations From A Statewide Mesonet And Atmospheric Profiling Systems, Rezaul Mahmood, Megan Schargorodski, Eric Rappin, Melissa Griffin, Patrick Collins, Kevin Knupp, Andrew Quilligan, Ryan Wade, Kevin Cary, Stuart Foster

High Plains Regional Climate Center: Staff Publications

A total solar eclipse traversed 37 the continental United States on August 21, 2017. It 38 was the first such event in 99 years and provided a rare opportunity to observe the atmospheric response from a variety of instrumented observational platforms. This paper discusses the high quality observations collected by the Kentucky Mesonet (www.kymesonet.org), a research-grade meteorological and climatological observation network consisting of 72 stations and measuring air temperature, precipitation, relative humidity, solar radiation, wind speed, and wind direction. The network samples the atmosphere, for most variables, every three seconds and then calculates and records observations every five minutes. During …

Irrigation Impacts On Minimum And Maximum Surface Moist Enthalpy In The Central Great Plains Of The Usa, Tianyi Zhang, Rezaul Mahmood, Xiaomao Lin, Roger A. Pielke Sr.

High Plains Regional Climate Center: Staff Publications

Agricultural activities notably alter weather and climate including near-surface heat content. However, past research primarily focused on dry bulb temperature without considering the role of water vapor (dew point temperature) on surface air heat content. When using dry bulb temperature trends to assess these changes, for example, not including concurrent trends in absolute humidity can lead to errors in the actual rate of warming or cooling. Here we examined minimum and maximum surface moist enthalpy, which can be expressed as “equivalent temperature.” Using hourly climate data in the Central Great Plains (Nebraska and Kansas) from 1990 to 2014, the averages …

Enhancing Acis Maps: Increasing Usability Through A Gis Portal, Natalie Umphlett, Warren Pettee, Bill Sorensen, Crystal J. Stiles

High Plains Regional Climate Center: Staff Publications

The High Plains Regional Climate Center (HPRCC) is one of six NOAA Regional Climate Centers (RCCs) in the United States that aims to provide timely climate data and information to the public for cost-effective decision-making. As part of a three-tiered approach to climate services, the RCCs address needs on the national, regional, state, and local scales for a variety of sectors including agriculture, energy, natural resource management, research, transportation, and water resources. Working together, the RCCs develop and disseminate a wide range of valueadded climate products and services.

One of the HPRCC’s most popular products is the Applied Climate Information …

Conducting A Drought-Specific Thira (Threat And Hazard Identification And Risk Assessment): A Powerful Tool For Integrating All-Hazard Mitigation And Drought Planning Efforts To Increase Drought Mitigation Quality, Elliot Wickham, Deborah J. Bathke, Tarik Abdel-Monem, Tonya K. Bernadt, Denise Bulling, Lisa M. Pytlikzillig, Crystal J. Stiles, Nicole Wall

High Plains Regional Climate Center: Staff Publications

In the United States, drought is the second costliest natural disaster, which leads to the need for increased drought mitigation efforts over time. However, drought planning has lagged behind other hazard mitigation efforts, which is likely due to the lack of a national drought planning policy. Although the Federal Emergency Management Agency (FEMA) requires all jurisdictions have a hazard mitigation plan (HMP) to receive pre-disaster mitigation funds, drought has only recently been a requirement in HMPs. In 2012, Nebraska witnessed its worse drought in recent history, which exposed the gaps in drought planning effectiveness at all jurisdictional levels. To address …

Spatial Conservation Planning Under Uncertainty: Adapting To Climate Change Risks Using Modern Portfolio Theory, Mitchell J. Eaton, Simeon Yurek, Zulqarnain Haider, Julien Martin, Fred A. Johnson, Bradley J. Udell, Hadi Charkhgard, Changhyun Kwon

United States Geological Survey: Staff Publications

Climate change and urban growth impact habitats, species, and ecosystem services. To buffer against global change, an established adaptation strategy is designing protected areas to increase representation and complementarity of biodiversity features. Uncertainty regarding the scale and magnitude of landscape change complicates reserve planning and exposes decision makers to the risk of failing to meet conservation goals. Conservation planning tends to treat risk as an absolute measure, ignoring the context of the management problem and risk preferences of stakeholders. Application of risk management theory to conservation emphasizes the diversification of a portfolio of assets, with the goal of reducing the …

Coastal Wetlands: A Synthesis, Charles S. Hopkinson, Eric Wolanski, Mark M. Brinson, Donald R. Cahoon, Gerardo M.E. Perillo

United States Geological Survey: Staff Publications

What are coastal wetland ecosystems, what are their limits of distribution, and where do they exist in the overall coastal landscape? There are several general definitions for wetlands, but the Ramsar definition is likely the most broadly encompassing (http://www.ramsar. org/), whereas others are more focused definitions tailored to country-specific protection and management policies (Mitsch and Gosselink, 2006). We offer a very general approach rather than a precise definition: coastal wetlands are ecosystems that are found within an elevation gradient that ranges between subtidal depths where light penetrates to support photosynthesis of benthic plants to the landward edge where the sea …

Pawnee Dam Inflow Design Flood (Idf) Update And Stage-Frequency Curve Development Using Rmcrfa, Jennifer P. Christensen, Joshua J. Melliger

United States Geological Survey: Water Reports and Publications

Pawnee Dam is one of the ten Salt Creek Dams designed and built in the 1960s to mitigate flooding in Lincoln, Nebraska. This short paper illustrates the update of the Pawnee Dam inflow design flood (IDF) through calibration to recent high flow events and the development of its stage-frequency or hydrologic loading curve with the U.S. Army Corps of Engineers’ Risk Management Center Reservoir Frequency Analysis (RMC-RFA) model. The IDF update follows Engineering Regulation 1110-8-2, Inflow Design Flood for Dams and Reservoirs, including unit hydrograph peaking and two antecedent pool elevations. Background information on the original design of the dam …

Comparing Reservoir Sediment Yield, Depletion, And Sustainability Within The Missouri River Basin, Daniel B. Pridal, Paul M. Boyd, Larry J. Morong

United States Geological Survey: Water Reports and Publications

Repetitive reservoir storage capacity surveys are often thought to provide one of the most accurate methods to assess basin sediment yield. The Omaha District conducts a large scale sediment data collection and analysis program for six Missouri River mainstem and twenty-two tributary reservoirs. An analysis was conducted to compare the sediment yield, reservoir capacity, depletion trends, and comparison between projects for effects on project sustainability. Trend analysis is complicated by temporal variation in conservation practices that affect sediment yield, new reservoir survey techniques, and revised capacity computation methods. Results provide insight on the variation in basin sediment yield, reservoir depletion …

Droughtscape, Winter 2019, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Drought intensified in California and Nevada, eased elsewhere

Year in Review: Drought spread and intensified in the West; record precipitation in the East

Drought impact summary for 4th quarter 2018

Drought impact summary 2018

Five states began drought plan updates in 2018

New web-based form makes submitting drought observations easier

FEMA risk assessment process tailored for drought

Upcoming events

Diatom-Inferred Records Of Paleolimnological Variability And Continental Hydrothermal Activity In Yellowstone National Park, Usa, Sabrina Brown

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Fossil diatoms were used to reconstruct paleoclimatic and hydrothermal conditions in Yellowstone National Park. First, an extensive literature review summarizes the current state of knowledge about eukaryotic organisms characteristic of continental hydrothermal environments. Eukaryotes in hydrothermal systems can live at extremes of acidity (pH 9.0), and at moderately high temperatures (<62 >^○C). Silicate and carbonate precipitation in continental hydrothermal environments is mediated by eukaryotic organisms, which are important members of biofilm communities.

A case study of alkaline-chloride sinter deposits in Yellowstone Lake and the Upper Geyser Basin inferred in-situ diatom growth rather than post-depositional accumulation of valves settling from …

Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang

Adam Liska Papers

Crop residue is an abundant resource for the potential production of biofuels, but a better understanding of its use on net carbon emissions must be developed to mitigate climate change. This analysis combines two established crop growth models (Hybrid-Maize and SoySim) with a simple soil and crop residue respiration model to estimate daily ecosystem respiration (ERe) from maize and soybean; ERe was estimated to be the sum of CO₂ emissions from the oxidation of the growing crop, crop residue, and soil organic carbon (SOC). Model-estimated CO₂ fluxes from irrigated continuous maize and irrigated maize–soybean cropping systems in eastern …

Optimizing Historic Preservation Under Climate Change: Decision Support For Cultural Resource Adaptation Planning In National Parks, Xiao Xiao, Erin Seekamp, Max Post Van Der Burg, Mitchell Eaton, Sandra Fatorić, Allie Mccreary

United States Geological Survey: Staff Publications

Climate change poses great challenges for cultural resource management, particularly in coastal areas. Cultural resources, such as historic buildings, in coastal areas are vulnerable to climate impacts including inundation, deterioration, and destruction from sea-level rise and storm-related flooding and erosion. However, research that assesses the trade-offs between actions for protecting vulnerable and valuable cultural resources under budgetary constraints is limited. This study focused on developing a decision support model for managing historic buildings at Cape Lookout National Seashore. We designed the Optimal Preservation Decision Support (OptiPres) model to: (a) identify optimal, annual adaptation actions for historic buildings across a 30-year …

Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, B.R. Noon, Z.H. Bowen, B.C. Fedy

United States Geological Survey: Staff Publications

Species–environment relationships for highly mobile species outside of the breeding season are often highly dynamic in response to the collective effects of everchanging climatic conditions, food resources, and anthropogenic disturbance. Capturing dynamic space-use patterns in a model-based framework is critical as model inference often drives place-based conservation planning. We applied dynamic occupancy models to broad-scale golden eagle Aquila chrysaetos survey data collected annually from 2006 to 2012 during the late summer post-fledging period in the western US. We defined survey sites as 10 km transect segments with a 1 km buffer on either transect side (n = 3540). Derived estimates …

Implementation Of An Occupancy-Based Monitoring Protocol For A Widespread And Cryptic Species, The New England Cottontail (Sylvilagus Transitionalis), Colin P. Shea, Mitchell J. Eaton, Darryl I. Mackenzie

United States Geological Survey: Staff Publications

Context. Designing effective long-term monitoring strategies is essential for managing wildlife populations. Implementing a cost-effective, practical monitoring program is especially challenging for widespread but locally rare species. Early successional habitat preferred by the New England cottontail (NEC) has become increasingly rare and fragmented, resulting in substantial declines from their peak distribution in the mid-1900s. The introduction of a possible competitor species, the eastern cottontail (EC),may also have played a role. Uncertainty surrounding how these factors have contributed to NEC declines has complicated management and necessitated development of an appropriate monitoring framework to understand possible drivers of distribution and dynamics.

Aims. …

Coastal Wetlands: A Synthesis, Charles S. Hopkinson, Eric Wolanski, Mark M. Brinson, Daonald R. Cahoon, Gerardo M.E. Perillo

United States Geological Survey: Staff Publications

What are coastal wetland ecosystems, what are their limits of distribution, and where do they exist in the overall coastal landscape? There are several general definitions for wetlands, but the Ramsar definition is likely the most broadly encompassing (http://www.ramsar. org/), whereas others are more focused definitions tailored to country-specific protection and management policies (Mitsch and Gosselink, 2006). We offer a very general approach rather than a precise definition: coastal wetlands are ecosystems that are found within an elevation gradient that ranges between subtidal depths where light penetrates to support photosynthesis of benthic plants to the landward edge where the sea …

Promoting Change In Common Tern (Sterna Hirundo) Nest Site Selection To Minimize Construction Related Disturbance., Peter C. Mcgowan, Jeffery D. Sullivan, Carl R. Callahan, William Schultz, Jennifer L. Wall, Diann J. Prosser

United States Geological Survey: Staff Publications

Due to the many challenges facing waterbird populations (Jia et al. 2018, Wetlands International 2018), it has become common practice to limit disturbance to breeding colonies whenever possible to maximize reproductive success. While this may require often unpopular management techniques including beach closures (Jorgensen et al. 2015, Mayo et al. 2015) and predator removal (Neuman et al. 2004, Stocking et al. 2017), such actions are sometimes necessary for the success of the colony. However, there are instances when eliminating disturbance is not possible and birds must be attracted to a new site. A common method for attracting waterbirds to a …

Optimizing Historic Preservation Under Climate Change: Decision Support For Cultural Resource Adaptation Planning In National Parks, Xiao Xiao, Erin Seekamp, Max Post Van Der Burg, Mitchell Eaton, Sandra Fatorić, Allie Mccreary

United States Geological Survey: Staff Publications

Climate change poses great challenges for cultural resource management, particularly in coastal areas. Cultural resources, such as historic buildings, in coastal areas are vulnerable to climate impacts including inundation, deterioration, and destruction from sea-level rise and storm-related flooding and erosion. However, research that assesses the trade-offs between actions for protecting vulnerable and valuable cultural resources under bud- getary constraints is limited. This study focused on developing a decision support model for managing historic buildings at Cape Lookout National Seashore. We designed the Optimal Preservation Decision Support (OptiPres) model to: (a) identify optimal, annual adaptation actions for historic buildings across a …

Assessment Of Chronic Low-Dose Elemental And Radiological Exposures Of Biota At The Kanab North Uranium Mine Site In The Grand Canyon Watershed, Danielle Cleveland, Jo Ellen Hinck, Julia S. Lankton

United States Geological Survey: Staff Publications

High-grade U ore deposits are in various stages of exploitation across the Grand Canyon watershed, yet the effects of U mining on ecological and cultural resources are largely unknown. Wecharacterized the concentrations of Al, As, Bi, Cd, Co, Cu, Fe, Pb, Hg, Mo, Ni, Se, Ag, Tl, Th, U, and Zn, gross alpha and beta activities, and U and Th radioisotopes in soil, vegetation (Hesperostipa comata, Artemisia tridentata, Tamarix chinensis), and rodents (Peromyscus maniculatus, P. boylii) to waste material at the Kanab North mine, a mine with decades-long surficial contamination, and compared the concentrations (P<0.01) to those at a premining site (Canyon Mine). Rodent tissues were also analyzed for radium-226 and microscopic lesions. Radioactivities and some elemental concentrations (e.g., Co, Pb, U) were greater in the Kanab North mine biological samples than in Canyon Mine biota, indicating a mining-related elemental signature. Mean rodent Ra-226 (111 Bq/kg dry weight [dry wt]) was 3 times greater than expected, indicating radioactive disequilibrium. Multiple soil sample U concentrations exceeded a screening benchmark, growth inhibition thresholds for sensitive plants, and an EC20 for a soil arthropod. Lesions associated with metals exposure were also observed more frequently in rodents at Kanab North than those at Canyon Mine but could not be definitively attributed to U mining. Our results indicate that Kanab North biota have taken up U mining-related elements owing to chronic exposure to surficial contamination. However, no literature-based effects thresholds for small rodents were exceeded, and only a few soil and vegetation thresholds for sensitive species were exceeded; therefore, adverse effects to biota from U mining-related elements at Kanab North are unlikely despite chronic exposure.