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In 1989, the Southern Nevada Water Authority (SNWA) launched the Southern Nevada Groundwater Development Project—a bold plan to construct a series of deep wells in east‐central Nevada to pump groundwater and send it to the Las Vegas region through 300 miles of pipeline. Before starting work on the project, SNWA conducted an environmental impact study and secured water rights in the valleys. Applications for additional new water rights were filed with Nevada State Engineer on the basis of uncaptured evapotranspiration. The SNWA spent decades and millions of dollars studying the hydrogeology of the region and developing computer models to demonstrate that the project would not have an unduly negative impact on the ecology or water users in the region. The project was opposed by environmental groups, native American tribes, and existing water rights holders. One of the protestants was the Cleveland Ranch in Spring Valley. Using the SNWA's own groundwater model, the ranch argued that the project would result in substantial harm to the ranch's water rights which included springs, wells, and a stream, and that the project would result in perpetual groundwater mining, which is forbidden by Nevada state policy. The Nevada State Engineer approved the project, but the decision was eventually reversed by Seventh District Court, which sided with the ranch and ruled that the project would never be sustainable and is therefore not compatible with Nevada policy. The project was formally abandoned in 2020. [ABSTRACT FROM AUTHOR]

Drought can affect both the quantity and quality of water in lakes and reservoirs, yet larger, highly managed waterbodies, such as Lake Mead, may be somewhat buffered from drought effects. From 2000 to present, Lake Mead has experienced a 71% decline in volume; however, influent water quality has remained high and consistent outflow volumes through Hoover Dam have been maintained. Furthermore, management activities, such as increased removal of phosphorus by wastewater dischargers and legacy contamination cleanup efforts, have been initiated since the drought began. These efforts have led to small improvements in values of water quality parameters, such as phosphorus, nitrogen, and perchlorate, despite loss of volume for dilution of constituents, and consequently, decreased residence time. As the drought continues, Lake Mead is projected to continue declining in volume, inflows are projected to become warmer, and the population of Las Vegas is projected to grow, potentially adding additional stress to the hydrologic system. Maintenance of outflow may mitigate some potentially negative consequences, and understanding the drivers behind continued high water quality despite prolonged drought is important to continue to maintain the health and vitality of the entire Lower Colorado River Basin. [ABSTRACT FROM AUTHOR]

The Las Vegas metropolitan area in Nevada has experienced extensive urban growth since 1950 coincident with regional and local climate change. This study explores the nonstationary flood history of the Las Vegas Wash (LVW) watershed by deconstructing it into its constituent physical drivers. Observations and reanalysis products are used to examine the hydroclimatology, hydrometeorology, and hydrology of flash flooding in the watershed. Annual peak flows have increased nonlinearly over the past seven decades, with an abrupt changepoint detected in the mid-1990s, which is attributed to the implementation of flood conveyance systems rather than changes in land use. The LVW watershed exhibits two pronounced flood seasons, associated with distinct synoptic atmospheric circulations: winter floods linked to inland-penetrating atmospheric rivers and summer floods linked to the North American monsoon. El Niño–Southern Oscillation also plays a role in modulating extreme rainfall and the resultant floods because annual maximum daily rainfall totals positively correlate with El Niño, with Spearman's correlation coefficient of 0.36 (p value < 0.05). Winter maximum daily rainfall totals have increased since 1950, whereas summer daily rainfall maxima have decreased. The trends in hydrometeorological drivers interact with urbanization to shift flood seasonality toward more frequent winter floods in the LVW watershed. A process-based understanding of the flood hydrology of the watershed also provides insights into flood frequency analysis and flood forecasting. [ABSTRACT FROM AUTHOR]

Key Takeaways: A federal water shortage declaration prompted the Southern Nevada Water Authority (SNWA) to work with state legislators to pass a bill prohibiting irrigation of "nonfunctional turf" in the Las Vegas Valley by the end of 2026. SNWA formed an advisory panel of community stakeholders to formally define functional and nonfunctional turf and make recommendations for implementing the new law. The advisory panel submitted a set of recommendations that was unanimously approved by SNWA's board of directors in January 2022. [ABSTRACT FROM AUTHOR]

Although several approaches have been proposed in the literature to utilize inverter-based distributed energy resources (DERs) in the secondary frequency control (SFC), challenges related to practically implementing SFC with inverter-based DERs have not been considered. These challenges include response time of DERs, the communication environment, and emulation of the actual Automatic Generation Control (AGC). This paper develops and implements a coordinated operation and control for below the substation resources such as inverter-based DERs and a utility-scale battery energy storage system (USBESS) to participate in the secondary frequency control. A linearized optimization problem is formulated to simultaneously determine optimal setpoints of participating resources and satisfy AGC requests in real time for the secondary frequency control. To mimic the actual process of AGC, a hardware- and software-in-the-loop-based experimental setup is developed with the integration of real-time digital simulators (RTDS), a centralized controller at the substation, and gateways as IoT devices, which are commonly used in practice to interface DERs to control and monitoring systems. The controller remains in listening mode until it receives an AGC signal. When it receives an AGC signal, it optimally dispatches the USBESS and DERs and monitors the change in power flow at the substation. The controller iteratively dispatches the participating resources considering their response time until the AGC request is satisfied. The proposed control is implemented on an actual feeder configuration located in Las Vegas, Nevada, in collaboration with NV Energy—the largest public utility in Nevada. The results illustrate that USBESS and DERs can be coordinated and dispatched to satisfy AGC requests for SFC. • Novel linearized optimization-based secondary frequency controller • High fidelity prototype for practical implementation of AGC on real system • Combined hardware-and software-in-the-loop-based real-time laboratory setup for AGC [ABSTRACT FROM AUTHOR]

The butterfly assemblage found at riparian upland plant restoration areas (after removal of the invasive plant, tamarisk (Tamarix ramosissima Ledebour)) along Las Vegas Wash was examined over four different months. Upland areas were planted with a variety of plants, however, those with a mesquite (Prosopis spp. Linneaus) component contained additional butterfly species relative to other plots. Detrended correspondence analysis demonstrated a gradient of butterfly species that corresponded with mesquite, age of stand, and homogenous areas of tamarisk. Some potential butterfly species went undetected; perhaps because required herbaceous understory plants were absent, or the need for greater densities of the hemiparasitic mistletoe (Phoradendron) (Nutt.) which is utilized by certain butterfly species. A single plot of exotic tamarisk, the near-past dominant shrub of the Wash landscape, was examined. An incursion of the beetle Diorhabda carinulata (Desbrochers), a phytophagous tamarisk control agent, appeared to affect tamarisk nectar production along with butterfly abundance at the plot. Butterfly response to nectar at inadvertent seep areas suggests these features are important for butterfly directed landscape restoration activities. Use of a characteristic butterfly community for identifying goals for upland restoration was valuable in describing end-points that incorporated assets of natural mesquite bosques. [ABSTRACT FROM AUTHOR]

The current study is one of few to utilize a randomized controlled trial design to evaluate the effects of a Day Reporting Center (DRC). Individuals on community supervision were randomly assigned to the DRC group or the control group. Path models examined the direct and indirect effects of DRC participation on social outcomes, revocations, and violations. Findings suggest that DRCs might effectively achieve their goals, at least in the short term and for some types of individuals. While these findings suggest that DRCs can be effective, more research is needed before definitive policy implications can be made. [ABSTRACT FROM AUTHOR]

The Covid-19 pandemic has had a disruptive impact on social life including the decision to marry. We suggest ways of examining the impacts of pandemics on destination weddings and provide a brief example of analysis on Las Vegas wedding under Covid-19. Specifically, a Break-Point regression using data from Clark County, Nevada treated marriages as the dependent variable and shutdown dates, income, and unemployment rates as independent variables. The results show that pandemic effects on destination weddings were short-lived and thus have important implications for planning and staffing decisions. [ABSTRACT FROM AUTHOR]

Copyright of Journal: American Water Works Association is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Fires, Asian, and Stratospheric Transport–Las Vegas Ozone Study (FAST-LVOS) was conducted in May and June of 2017 to study the transport of ozone (O 3) to Clark County, Nevada, a marginal non-attainment area in the southwestern United States (SWUS). This 6-week (20 May–30 June 2017) field campaign used lidar, ozonesonde, aircraft, and in situ measurements in conjunction with a variety of models to characterize the distribution of O 3 and related species above southern Nevada and neighboring California and to probe the influence of stratospheric intrusions and wildfires as well as local, regional, and Asian pollution on surface O 3 concentrations in the Las Vegas Valley (≈ 900 m above sea level, a.s.l.). In this paper, we describe the FAST-LVOS campaign and present case studies illustrating the influence of different transport processes on background O 3 in Clark County and southern Nevada. The companion paper by Zhang et al. (2020) describes the use of the AM4 and GEOS-Chem global models to simulate the measurements and estimate the impacts of transported O 3 on surface air quality across the greater southwestern US and Intermountain West. The FAST-LVOS measurements found elevated O 3 layers above Las Vegas on more than 75 % (35 of 45) of the sample days and show that entrainment of these layers contributed to mean 8 h average regional background O 3 concentrations of 50–55 parts per billion by volume (ppbv), or about 85–95 µ g m -3. These high background concentrations constitute 70 %–80 % of the current US National Ambient Air Quality Standard (NAAQS) of 70 ppbv (≈ 120 µ g m -3 at 900 m a.s.l.) for the daily maximum 8 h average (MDA8) and will make attainment of the more stringent standards of 60 or 65 ppbv currently being considered extremely difficult in the interior SWUS. [ABSTRACT FROM AUTHOR]

The Las Vegas Formation (LVF) is a well-characterized sequence of groundwater discharge (GWD) deposits exposed in and around the Las Vegas Valley in southern Nevada. Nearly monolithologic bedrock surrounds the valley, which provides an excellent opportunity to test the hypothesis that GWD deposits include an aeolian component. Mineralogical data indicate that the LVF sediments are dominated by carbonate minerals, similar to the local bedrock, but silicate minerals are also present. The median particle size is ~35 μm, consistent with modern dust in the region, and magnetic properties contrast strongly with local bedrock, implying an extralocal origin. By combining geochemical data from the LVF sediments and modern dust, we found that an average of ~25% of the LVF deposits were introduced by aeolian processes. The remainder consists primarily of authigenic groundwater carbonate as well as minor amounts of alluvial material and soil carbonate. Our data also show that the aeolian sediments accumulated in spring ecosystems in the Las Vegas Valley in a manner that was independent of both time and the specific hydrologic environment. These results have broad implications for investigations of GWD deposits located elsewhere in the southwestern U.S. and worldwide. [ABSTRACT FROM AUTHOR]

The coronavirus epidemic or Covid-19 started in Wuhan, China in December 2019 and has severely impacted all aspects of life worldwide. It has resulted in 216 million infections and 4.5 million deaths so far globally. In the present article, the impact of coronavirus on gaming revenue of the state of Nevada will be investigated. Gaming revenue time series data for the period January 1988-November 2020 was obtained from the Gaming Control Board of Nevada. In addition to the trend and seasonality components, the terrorist attack of September 2011, the recession of 2008, and the coronavirus pandemic are also included in the Machine Learning (ML) prediction models for gaming revenues. The goals of this study are to estimate the effect of the coronavirus pandemic on gaming revenue of the Las Vegas Strip casinos, and to forecast gaming revenue and predict time to recovery. The results of this analysis show that the impact of coronavirus has been drastic, but the economic recovery has been rather fast. [ABSTRACT FROM AUTHOR]

While studies of urban acoustics are typically restricted to the audio range, anthropogenic activity also generates infrasound (<20 Hz, roughly at the lower end of the range of human hearing). Shutdowns related to the COVID-19 pandemic unintentionally created ideal conditions for the study of urban infrasound and low frequency audio (20–500 Hz), as closures reduced human-generated ambient noise, while natural signals remained relatively unaffected. An array of infrasound sensors deployed in Las Vegas, NV, provides data for a case study in monitoring human activity during the pandemic through urban acoustics. The array records a sharp decline in acoustic power following the temporary shutdown of businesses deemed nonessential by the state of Nevada. This decline varies spatially across the array, with stations close to McCarran International Airport generally recording the greatest declines in acoustic power. Further, declines in acoustic power fluctuate with the time of day. As only signals associated with anthropogenic activity are expected to decline, this gives a rough indication of periodicities in urban acoustics throughout Las Vegas. The results of this study reflect the city's response to the pandemic and suggest spatiotemporal trends in acoustics outside of shutdowns. [ABSTRACT FROM AUTHOR]

Mycoplasma agassizii is a common cause of upper respiratory tract disease in Mojave desert tortoises (Gopherus agassizii). So far, only two strains of this bacterium have been sequenced, and very little is known about its patterns of genetic diversity. Understanding genetic variability of this pathogen is essential to implement conservation programs for their threatened, long-lived hosts. We used next generation sequencing to explore the genomic diversity of 86 cultured samples of M. agassizii collected from mostly healthy Mojave and Sonoran desert tortoises in 2011 and 2012. All samples with enough sequencing coverage exhibited a higher similarity to M. agassizii strain PS6T (collected in Las Vegas Valley, Nevada) than to strain 723 (collected in Sanibel Island, Florida). All eight genomes with a sequencing coverage over 2x were subjected to multiple analyses to detect single-nucleotide polymorphisms (SNPs). Strikingly, even though we detected 1373 SNPs between strains PS6T and 723, we did not detect any SNP between PS6T and our eight samples. Our whole genome analyses reveal that M. agassizii strain PS6T may be present across a wide geographic extent in healthy Mojave and Sonoran desert tortoises. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Little is known about correlates of physical activity of Asian and Asian-Pacific Islander Americans (AAPI). Knowledge of these correlates could be useful in promoting physical activity. Purpose: to identify demographic and environmental correlates of physical activity among AAPI. Methods: Participants resided in the Las Vegas, Nevada area, and completed a 52-item telephone administered questionnaire that assessed physical activity behavior, environmental supports for physical activity and demographic factors. Environmental factors included the presence of neighborhood sidewalks, park availability, and nearby grocery stores were combined to create the variable "environmental physical activity supports" (EPAS). Neighborhood crime, pleasantness of the neighborhood for walking, and the presence of loose dogs combined to form "neighborhood safety." Logistic regression was used to identify predictors of physical activity. Potential predictors included age, gender, BMI, employment, educational attainment, neighborhood safety, and EPAS. Results: 263 respondents completed the survey. With the exception of living near a grocery store, respondents reported residing in neighborhoods that are generally supportive of physical activity. However, EPAS was the sole significant predictor of physical activity behavior (OR = 1.52, Cl = 1.06-2.17). Age and educational attainment unexpectedly failed to predict physical activity. Conclusions: Supportive physical activity environments associate with physical activity behavior among AAPI. [ABSTRACT FROM AUTHOR]

This paper discusses a dual approach of case study and research survey to investigate the complex factors in sustaining academic library digitization programs. The case study involves the background of the University of Nevada, Las Vegas (UNLV) Libraries' digitization program and elaborates on the authors' efforts to gain staff support for this program. A related survey was administered to all Association of Research Libraries (ARL) members, seeking to collect baseline data on their digital collections, understand their respective administrative frameworks, and to gather feedback on both negative obstacles and positive inputs affecting their success. Results from the survey, combined with the authors' local experience, point to several potential success factors including staff skill sets, funding, and strategic planning. [ABSTRACT FROM AUTHOR]

Looks at urban water use in Phoenix, Arizona and Las Vegas, Nevada. Tendency to favor water-intensive landscapes in the arid, urban homes; Advantage of water's transformative powers to create landscapes based more on ideals and dreams that on the environmental realities of place; Benefit of the Roosevelt Dam to Phoenicians.

Focuses on the evolution of an academic library Web site of the University of Nevada-Las Vegas Libraries. Revisions of the libraries; Presence of academic libraries on the World Wide Web; Progress of academic library in terms of creating a user-friendly and content-rich library Web site.

Discusses the applications used by business and public institutions to plan and implement changes in the way libraries operate. Requirements and benefits of library re-engineering and process improvement; Information on the method of change used in the Interlibrary Loan (ILL) section of the Dickinson Library at the University of Nevada in Las Vegas (UNLV); Changes in the ILL unit.

Surface evaporation in arid regions determines the fraction of rainfall that remains to support vegetation and recharge. The surface evaporation capacitor approach was used to estimate rainfall partitioning to surface evaporation and leakage into deeper layers. The surface evaporation capacitor estimates a soil‐specific surface evaporation depth and critical storage capacitance that defines rainfall events that exceed local capacitance and result in leakage into deeper layers protected from surface evaporation. A decade‐long record of hydrologic observations in deep and barren lysimeters near Las Vegas revealed the dominance of a few large rainfall events in generating leakage and increasing interannual soil water storage. The surface evaporation capacitor was used to estimate mean annual surface evaporation and leakage protected from surface evaporation in all arid regions globally. About 13% of arid region rainfall contributes to soil water storage (in the absence of vegetation), similar to 11% found in the lysimeter study. Key Points: The surface capacitor model was applied for global arid regions and estimated that 13% of rainfall amount is protected from soil evaporationA soil‐dependent characteristic depth and critical water content determine the rainfall amounts required for redistribution to deeper layersOnly three rainfall events during one decade contributed to water storage beneath surface of a desert soil lysimeter in Nevada [ABSTRACT FROM AUTHOR]

Introduction : This study presents the prediction of driver yielding compliance and pedestrian tendencies to press pushbuttons at signalized mid-block Danish offset crosswalks. Method: It applies Bayesian Networks (BNs) analysis, which is basically a graphical non-functional form model, on observational survey data collected from five signalized crosswalks in Las Vegas, Nevada. The BNs structures were learnt from the data by the application of several score functions. By considering prediction accuracy and the Area under the Receiver Operating Characteristic (ROC) curves, the BN learnt using the Bayesian Information Criterion (BIC) score resulted as the best network structure, compared to the ones learnt using K2 and the Akaike Information Criterion (AIC). The BIC score-based structure was then used for parameter learning and probabilistic inference. Results: Results show that, when considering an individual scenario, the highest predicted yielding compliance (81%) is attained when pedestrians arrive at the crosswalk while the flashes are active, whereas the lowest predicted yielding compliance (23.4%) is observed when the pedestrians cross between the yield line and advanced pedestrian crosswalk sign. On the other hand, crossing within marked stripes, approaching the crosswalk from the near side of the pushbutton pole, inactive flashing lights, and being the first to arrive at the crosswalk result in relatively high-predicted probabilities of pedestrians pressing pushbutton. Furthermore, with a combination of scenarios, the maximum achievable predicted yielding probability is 87.5%, while that of pressing the button was 96.3%. Practical applications: Traffic engineers and planners may use these findings to improve the safety of crosswalk users. • This study applied Bayesian Networks (BNs) to study drivers and pedestrians' behaviors at signalized mid-block crosswalks. • The BNs' structures and parameters were learnt from the data collected from five crosswalks located in Las Vegas, Nevada. • The BN learnt using the Bayesian Information Criterion (BIC) score resulted as the best network structure. • The highest predicted yielding compliance (81%) was when pedestrians arrive at the crosswalk while the flashes are active. • Crossing zone, approach side, and inactive flashes resulted in high predicted probabilities of pedestrians pushing the button. [ABSTRACT FROM AUTHOR]

Discusses the measures that the University of Nevada in Las Vegas (UNLV) implemented to address the multitiered problems that confronted its library. Constraints and problems experienced by academic libraries in rapidly-developing communities; UNLV's implementation of the credit card policy in its library; Impact of the credit card policy to library users.