Hydrograph responses to geomorphic model watershed characteristics and precipitation variables

The primary objective of the Watershed Model Studies Project, reported herein, was to ascertain the effect of selected watershed characteristics on hydrograph parameters under a rainfall simulator. Since most of the runoff contributing to the peak flow was found to emanate from the lower half of the drainage, a measure of watershed eccentricity utilizing easily measured properties in that area is derived and evaluated as a reliable predictor of peak magnitude. In the process of isolating watershed shape, slope, size, drainage pattern, and soil depth were isolated and, along with rainfall intensity, direction of storm movement, and antecedent moisture conditions, evaluated for the models. Studies were made into the similarities between the models and real world watersheds. Three of the several conclusions are 1) the models exhibit hydrologic responses similar to those of a wide range of real watersheds; 2) watershed shape, of itself, does not have a tremendous effect on peak magnitude, and 3) watershed eccentricity is an effective, easily measured, meaningful, and useful expression of watershed shape insofar as that characteristic affects maximum peak flows and certain time parameters of the hydrograph.     

On the origins of trapped helium,neon and argon isotopic variations in meteorites—II. Carbonaceous meteorites

Data are presented from stepwise heating experiments on five carbonaceous chondrites: Alais, Ivuna, Orgueil, Cold Bokkeveld and Nogoya. The data indicate the presence of two isotopically distinct major trapped components, components A and B. Two additional components, ‘C’ and ‘E,’ were isolated on the basis of neon isotopic structure. Components B and C, found in. gas-rich meteorites, are attributed to ion implantation by the present day solar wind and solar flares respectively. Component A is interpreted as a mixture of component E and component D (Paper I), where component D is identified with the primitive solar wind and component E is assigned an extra solar system origin.     

Coupling behavior of shear deformation and end rotation of elastomeric seismic isolation bearings

This paper presents a mechanical model for predicting the behavior of elastomeric seismic isolation bearings subject to combined end rotations and shear deformation. The mechanical model consists of a series of axial springs at the top, mid‐height and bottom of the bearing to vertically reproduce asymmetric bending moment distribution in the bearings. The model can take into account end rotations of the bearing, and the overall rotational stiffness includes the effect of the variation of vertical load on the bearing and the imposed shear deformation. Static bending tests under various combinations of vertical load and shear deformation were performed to identify the mechanical characteristics of bearings. The test results indicate that bearing rotational stiffness increases with increasing vertical load but decreases with increasing shear deformation. Simulation analyses were conducted to validate the new mechanical model. The results of analyses using the new model show very good agreement with experimental observations. A series of seismic response analyses were performed to demonstrate the dynamic behavior of top‐of‐column isolated structures, a configuration where the end rotations of isolation bearings are typically expected to be larger. The results suggest that the end rotations of elastomeric bearings used in practical top‐of‐column isolated structures do not reduce the stability limit of isolation system. Copyright © 2016 John Wiley & Sons, Ltd.     

Causes of Weather-Related Crashes in Salt Lake County,Utah

In 2010, the World Health Organization declared 2011 to 2020 the Decade of Action for Road Safety in response to the enormous toll that roadway crashes take on individuals, communities, and national economies. More than 6.2 million vehicle crashes occurred in the United States in 2015, resulting in around 2.4 million injuries and more than 35,000 fatalities. Motor vehicle crashes in the United States in 2015 had an economic cost of $836 billion, equal to nearly 5 percent of the U.S. gross domestic product. For this study, more than 122,000 crashes occurring in Salt Lake County, Utah, from 2012 to 2016 were analyzed to see how weather conditions affected the number and type of crashes observed. Approximately 12 percent of crashes occurred under “adverse weather conditions.” Weather-related crashes were most likely in the winter season and were very highly correlated with monthly snowfall. Although the greatest number of crashes occurred during evening rush hours, adverse weather-related crashes made up a larger percentage of crashes from 5 to 7 a.m. Although excessive speed was much more likely to be a factor in crashes during adverse weather, such crashes, on average, were less severe. Roadway slope also played a significant role, with slight increases causing more crashes.     

Exploring the Digital Divide in an Australian Regional City: a case study of Albury

The ‘digital divide’ is generally considered to be the gap between people who have access to information and communication technologies (ICT) and those who do not, and an issue of significant social justice. This paper presents findings from research that explored the digital divide within the regional city of Albury. The study focused on assessing whether there was a digital divide; identifying strategies to address any divide; and developing a methodology that could be used to explore the digital divide in other contexts. Data were gathered using semi-structured interviews, focus groups, and a telephone survey of city residents. Findings demonstrated that a digital divide existed in that there were differences in computer access in relation to income and different locations within the city, and for access to the Internet by age, education and income levels. Overall, the patterns indicated that those with lower education and income and the elderly reported lower levels of access to ICT. Drawing on the research findings we suggest some practical ways of addressing the digital divide that could be applied to other similar locations where a digital divide exists, such as providing technical support and training, improved access to and awareness of ICT services, and facilitating access to ICT services such as the provision of appropriate hardware and software for disadvantaged groups. Our view is that the mixed-method approach we employed provided helpful, reliable information at reasonable cost and could be considered by other researchers and local governments.     

Three‐dimensional inversion of towed streamer electromagnetic data

A towed streamer electromagnetic system capable of simultaneous seismic and electromagnetic data acquisition has recently been developed and tested in the North Sea. We introduce a 3D inversion methodology for towed streamer electromagnetic data that includes a moving sensitivity domain. Our implementation is based on the 3D integral equation method for computing responses and Fréchet derivatives and uses the re‐weighted regularized conjugate gradient method for minimizing the objective functional with focusing regularization. We present two model studies relevant to hydrocarbon exploration in the North Sea. First, we demonstrate the ability of a towed electromagnetic system to detect and characterize the Harding field, a medium‐sized North Sea hydrocarbon target. We compare our 3D inversion of towed streamer electromagnetic data with 3D inversion of conventional marine controlled‐source electromagnetic data and observe few differences between the recovered models. Second, we demonstrate the ability of a towed streamer electromagnetic system to detect and characterize the Peon discovery, which is representative of an infrastructure‐led shallow gas play in the North Sea. We also present an actual case study for the 3D inversion of towed streamer electromagnetic data from the Troll field in the North Sea and demonstrate our ability to image all the Troll West Oil and Gas Provinces and the Troll East Gas Province. We conclude that 3D inversion of data from the current generation of towed streamer electromagnetic systems can adequately recover hydrocarbon‐bearing formations to depths of approximately 2 km. We note that by obviating the need for ocean‐bottom receivers, the towed streamer electromagnetic system enables electromagnetic data to be acquired over very large areas in frontier and mature basins for higher acquisition rates and relatively lower cost than conventional marine controlled‐source electromagnetic methods.     

Effect of Different Sampling Methodologies on Measured Methane Concentrations in Groundwater Samples

Analysis of dissolved light hydrocarbon gas concentrations (primarily methane and ethane) in water supply wells is commonly used to establish conditions before and after drilling in areas of shale gas and oil extraction. Several methods are currently used to collect samples for dissolved gas analysis from water supply wells; however, the reliability of results obtained from these methods has not been quantified. This study compares dissolved methane and ethane concentrations measured in groundwater samples collected using three sampling methods employed in pre‐ and post‐drill sampling programs in the Appalachian Basin. These include an open‐system collection method where 40 mL volatile organic analysis (VOA) vials are filled directly while in contact with the atmosphere (Direct‐Fill VOA) and two alternative methods: (1) a semi‐closed system method whereby 40 mL VOA vials are filled while inverted under a head of water (Inverted VOA) and (2) a relatively new (2013) closed system method in which the sample is collected without direct contact with purge water or the atmosphere (IsoFlask^®). This study reveals that, in the absence of effervescence, the difference in methane concentrations between the three sampling methods was relatively small. However, when methane concentrations equaled or exceeded 20 mg/L (the approximate concentration at which effervescence occurs in the study area), IsoFlask^® (closed system) samples yielded significantly higher methane concentrations than Direct‐Fill VOA (open system) samples, and Inverted VOA (semi‐closed system) samples yielded lower concentrations. These results suggest that open and semi‐closed system sample collection methods are adequate for non‐effervescing samples. However, the use of a closed system collection method provides the most accurate means for the measurement of dissolved hydrocarbon gases under all conditions.     

Comparison of flux measurements with open- and closed-path gas analyzers above an agricultural field and a forest floor

Comparison was made of the flux measurements of a closed-path CO₂/H₂O analyzer and an open-path H₂O analyzer above a clover field and the forest floor of a Douglas-fir stand. The attenuation of the gas concentration fluctuations caused by the sampling tube of the closed-path analyzer resulted in underestimation of the H20 flux above both surfaces. The degree of underestimation above the clover field depended on wind speed, but was smaller than that calculated from the transfer function for laminar flow in a circular tube and the scalar cospectrum in the neutral and unstable surface layer. Above the forest floor CO₂ fluctuations led those of H₂O by 0.7s. The implications of this are discussed regarding the determination of the time delay caused by the sampling tube of the closedpath analyzer. The day-time CO₂ efflux from the forest floor, averaged over three days, was 0.043 mg/(m²s).     

The influence of oceanic conditions on the hot European summer of 2003

The summer of 2003 was the hottest on record throughout much of Europe. Understanding how the event developed and the factors that contributed to it may help us improve seasonal forecasting models and assess the risk of such events in the future. This study uses atmosphere-only model integrations and observed data to investigate the potential predictability of the climate anomalies, and in particular the impact that the warming in the Indian Ocean and Mediterranean Sea had on the development of the temperature anomalies. The model results suggest that the temperature anomalies were potentially predictable and that both Indian Ocean and Mediterranean sea surface temperature anomalies contributed to the development of the observed warm and dry anomalies over Europe. Furthermore, it was found that, in the model, the Mediterranean anomalies contributed most strongly to the warming in June and July and the Indian Ocean anomalies enabled the positive temperature anomalies to persist into August. Previously published work has described the role of the Indian monsoon in modulating the seasonal cycle in rainfall over Europe. Comparison with this work suggests a mechanism by which warming in the Indian Ocean may have contributed to the persistence of the temperature and precipitation anomalies into August.