Debris flows in alpine environments are prone to occur in the context of global climate change (i.e., elevated air temperature and higher frequency of strong precipitation events). (Alluvial) Fans ...often develop at the outlet of tributaries after high‐intensity debris flows. Most debris‐flow fans in alpine canyon areas extend directly to the main river channel and become the forefront of the interaction between the tributary gully and the main river channel. Clarifying the development processes/dynamics, evolutionary mechanisms and driving factors of alluvial fans would shed light on understanding the geomorphological effects and genesis of river valleys in alpine canyon areas. Here, we report the development of debris‐flow fan at the outlet of the Tianmo Gully, a formerly hazard‐free but currently hazard‐active tributary of the Parlung Tsangpo Basin, Southeast Tibet, where debris flows have occurred frequently in the last two decades. Combining remote‐sensing images, DEM data, UAV aerial photography, RTK topographic survey and other fieldwork, the development processes and morphological characteristics of the Tianmo fan under the influence of four large debris flows were analysed. Both primary events (described as episodic debris‐flow events characterized by high‐magnitude mass movement) and secondary events (corresponding to perennial stream flow processes with much lower sediment concentrations) affected the development of the Tianmo fan. Episodic debris‐flow events drastically shape the macroscopic morphology of the fan, with rapid deposition and expansion of the fan body, whereas perennial stream flow processes slowly modulate the fan during the intermittent period between debris flows, mainly with gradual retrogressive incision and lateral migration of flow channel on the fan body. Influenced by the strong sediment‐transport process of debris flows and the alluvial fan development, the planform of the Parlung Tsangpo River evolved from a relatively narrow and single‐thread pattern to an alternating‐wide‐and‐narrow pattern, with a corresponding staircase‐like longitudinal profile.
We investigated alluvial fan development and geomorphic effects of Tianmo Gully in Southeast Tibet, an alpine canyon area where debris flows have been active in recent decades under a changing climate. Debris flow is the key driver for the fan development, whereas runoff reworking is non‐negligible, and strong interactions exist between the fan and the main river. Fan development exerts big impacts on the morphology evolution of the main river, forming an alternating‐wide‐and‐narrow planform pattern with a staircase‐like longitudinal profile.
Climate change simulation based on 30-member ensemble of Voeikov Main Geophysical Observatory RCM (resolution 25 km) for northern Eurasia is used to drive hydrological model CaMa-Flood. Using this ...modeling framework, we evaluate the uncertainties in the future projection of the peak river discharge and flood hazard by 2050–2059 relative to 1990–1999 under IPCC RCP8.5 scenario. Large ensemble size, along with reasonably high modeling resolution, allows one to efficiently sample natural climate variability and increase our ability to predict future changes in the hydrological extremes. It has been shown that the annual maximum river discharge can almost double by the mid-XXI century in the outlets of major Siberian rivers. In the western regions, there is a weak signal in the river discharge and flood hazard, hardly discernible above climate variability. Annual maximum flood area is projected to increase across Siberia mostly by 2–5% relative to the baseline period. A contribution of natural climate variability at different temporal scales to the uncertainty of ensemble prediction is discussed. The analysis shows that there expected considerable changes in the extreme river discharge probability at locations of the key hydropower facilities. This suggests that the extensive impact studies are required to develop recommendations for maintaining regional energy security.
Alcohol outlet accessibility is positively associated with alcohol consumption, although this relationship has not been thoroughly examined in pregnant women. The present study examines the ...relationship between proximity and density of alcohol outlets and risk for low birth weight (LBW: <2,500 grams) and preterm birth (PTB: <37 weeks gestational age), and is the first Canadian study to investigate this association.
Maternal accessibility to alcohol outlets was specified using a gravity-type measure of accessibility, which provides the amount of accessibility that a given household has to liquor stores within 30-minutes of their home. All singleton newborns without congenital anomalies that were born between February 2009 and February 2014 at London Health Sciences Centre in London, Ontario, were included in this cohort.
The sample consisted of 25,734 live births, of which 5.8% were LBW and 7.6% were PTB. Only 2.0% of women reported alcohol use during pregnancy. Alcohol outlet gravity was positively correlated with the percentage of mothers living in poverty (rs = 0.33, p < 0.001) and in single-parent families (rs = 0.39, p < 0.001), and who self-identify as visible minorities (rs = 0.45, p < 0.001). Alcohol outlet gravity increased the odds that mothers drank alcohol during pregnancy (OR 1.05; 95% CI: 1.02, 1.07), although the association was weak. Furthermore, alcohol outlet gravity did not increase the likelihood of a LBW or PTB infant.
Women with high accessibility to alcohol outlets are more likely to consume alcohol during pregnancy, but greater alcohol outlet accessibility does not translate into poor birth outcomes.
Background and Aims
Social ecological theories suggest that greater community alcohol availability and individual drinker characteristics should jointly affect drinking patterns and the use of ...drinking contexts. We assessed relationships of demographic and personality characteristics of individual drinkers and environmental characteristics at the city‐level to measures of drinking patterns and use of drinking contexts.
Design
Multi‐level statistical analyses of archival and survey data from 50 cities in California, USA.
Settings
An ecological sample of 50 geographically distinct cities with populations from 50 000 to 500 000 people.
Participants
General population telephone survey of 8553 adults 18 years of age and older stratified by cities.
Measurements
Archival data on city‐level alcohol outlet densities were combined with individual survey data identifying community conditions, individual demographic and psychosocial characteristics, frequencies of use of drinking contexts and drinking patterns.
Findings
Greater on‐premise outlet densities were related to greater drinking frequencies (b = 2.9671, z = 4.688, P < 0.001) and volumes (b = 0.6274, z = 3.394, P < 0.001) and use of on‐premises drinking places (bars, b = 0.3340, z = 2.645, P < 0.006 and restaurants, b = 0.1712, z = 2.770, P = 0.005). Individual demographic and personality characteristics were related to drinking and use of drinking contexts. For example, greater impulsivity was related to greater drinking frequencies (b = 0.2001, z = 2.088, P = 0.023) and logged quantities (b = 0.0151, z = 2.009, P = 0.026) and proportionately more drinking at bars (b = 0.0332, z = 2.016, P = 0.026) and parties (b = 0.1712, z = 2.770, P = 0.004).
Conclusion
Community availability of alcohol and individual drinker characteristics appear to act jointly to affect drinking levels and use of drinking contexts. These effects may increase risks related to drinking in some contexts (e.g. bars) much more than others (e.g. at friends' or relatives' homes).
Water temperatures control life histories and diversity of aquatic species. Hydropower regulation, particularly in high head systems, alters natural water temperature regimes, which may have profound ...and long‐term impacts on aquatic environments. Temperatures in by‐pass sections and reaches affected by residual/environmental minimum flows fluctuate more than in natural flow regimes, driven more by influence of air temperatures. Reaches downstream of power plant outlets tend to become warmer in winter and colder in summer, driven by stratification behind the reservoir dam. In hydro‐peaked systems high‐low temperature effects may thus be aggravated. We review alterations of hydropower to natural thermal regimes, impacts on key organisms in terms of survival, development and behavioral thresholds, and potential mitigation measures, with focus on Atlantic salmon and brown trout in high northern latitude stream systems. Previous syntheses have focused mainly on flow changes and ecological impacts. Temperature effects may not always be correlated with flow changes, although there are some unique challenges with temperature changes in far northern latitudes, for example, related to the seasonal and colder climates. To help knowledge‐based management and identify potential knowledge gaps, we review how hydropower regulation may impact seasonal water temperatures, what impacts changes to stream system temperature regimes may have to key organisms, for example, Atlantic salmon and brown trout, and what adaptations and behavioral variations they may exhibit to respond to changed temperature regimes, and finally what good practices can be recommended for mitigating temperature impacts. This synthesis indicates that there are impacts to the fish and their supporting food webs, in particular related to growth and development, and the potential for negative impacts seems higher, and better studied, than positive impacts in northern river systems. Some of these impacts may be modified by directed hydropower regulation practices, but here effect studies and knowledge are limited.
The contemporary media systems present hybrid logics and features that imply an increasingly interdependence among actors, media and communication formats. The hybrid media system approach underlines ...that legacy news media and non-elite media actors construct flows of news through different media technologies and according to complex temporal structures. A media environment arises in which traditional distinctions between concepts like ‘online’ and ‘offline’, ‘producer’ and ‘audience’, ‘citizens’ and ‘journalists’ become blurred. The emphasis appears to be on change more than continuity, and on difference more than similarity. Although the hybrid media approach is appreciated by numerous contemporary media scholars, hybridity in media often remains an all-encompassing concept and few attempts have been made to measure it. This article assesses the level of hybridity by investigating journalists’ uses of sources. It considers mainly journalists’ use of sources by the medium for which they work (from newspapers to web or radio) and the kinds of news that they produce (hard or soft news, business/finance, tech/science). The assumption is, therefore, that, within a homogeneously hybridized media system, journalists use the same sources regardless of the medium for which they work and the topics with which they deal. This objective is pursued by analysing the data collected via a survey conducted by means of structured interviews with a sample of 1424 Italian journalists between October and November 2016. The findings show that the analytical distinction among platforms for which journalists work still matters in terms of sources. Except for the use of Facebook and Google, journalists have still very defined paths to collect sources according to the medium they work for. The article has implications also for the literature on journalists’ authority and expertise.
AbstractLeakage dissolution and the induced internal erosion failures in earth-fill dams and foundations significantly threaten the long-term operational safety of geotechnical structures. This ...phenomenon can be more dangerous in conjunction with the damage of internal water-supply bottom outlets due to the leakage-induced pore water pressure, which reduces soil effective stresses and therefore affects dam stability. However, the internal instability induced by bottom outlet leakage has not been thoroughly investigated. Therefore, in this paper, a bottom outlet leakage model testing system is designed to simulate and investigate bottom outlet leakage in earth-fill dams. This leads to a detailed investigation on seepage behavior in earth-fill dams, by considering the different positions of bottom outlet leakage, i.e., at the upstream side, the middle dam section, and the downstream side. Furthermore, numerical analyses are carried out to study the leakage-induced slope instability. Based on the experimental and numerical results, the following phenomena are observed: (1) when bottom outlet leakage occurs, the whole phreatic line is elevated and hydraulic head increases significantly at the leaking position. The equipotential line bends to the point of leakage and the seepage field at the leakage point is drastically affected; (2) in the direction perpendicular to the bottom outlet, the hydraulic head decreases nonlinearly as the distance from the bottom outlet increases; (3) seepage discharge increases as hydraulic head increases, in an approximately nonlinear relation. The seepage discharge due to bottom outlet leakage at the upstream side of the dam is much larger than that at the middle dam section and the downstream side; (4) the factor of safety of slope stability decreases as leakage-induced hydraulic head increases. The potential failure surface of the dam slope is circular when leakage occurs at the middle dam section and the downstream side. For the failure at the upstream side, seepage-induced tensile stress reaches the tensile strength, which leads to slope damage; and (5) based on the experimental and numerical investigations, suggestions are given for designing the monitoring scheme for bottom outlet leakage problems in earth-fill dams.
Flameless combustion offers many advantages over conventional combustion, particularly uniform temperature distribution and lower emissions. In this paper, a new strategy is proposed and adopted to ...scale up a burner operating in flameless combustion mode from a heat release density of 5.4-21MW/m3 (thermal input 21.5-84.7kW) with kerosene fuel. A swirl flow based configuration was adopted for air injection and pressure swirl type nozzle with an SMD 35-37 mu m was used to inject the fuel. Initially, flameless combustion was stabilized for a thermal input of 21.5kW (=5.37MW/m3). Attempts were made to scale this combustor to higher intensities i.e. 10.2, 16.3 and 21.1MW/m3. However, an increase in fuel flow rate led to incomplete combustion and accumulation of unburned fuel in the combustor. Two major difficulties were identified as possible reasons for unsustainable flameless combustion at the higher intensities. (i) A constant spray cone angle and SMD increases the droplet number density. (ii) Reactants dilution ratio (Rdil ) decreased with increased thermal input. To solve these issues, a modified combustor configuration, aided by numerical computations was adopted, providing a chamfer near the outlet to increase the Rdil . Detailed experimental investigations showed that flameless combustion mode was achieved at high intensities with an evenly distributed reaction zone and temperature in the combustor at all heat intensities. The emissions of CO, NO x and HC for all heat intensities (ETHcurren =1-0.6) varied between 11-41, 6-19 and 0-9ppm, respectively. These emissions are well within the range of emissions from other flameless combustion systems reported in the literature. The acoustic emission levels were also observed to be reduced by 8-9dB at all conditions.
The majority of rivers around Europe have been modified in one way or another, and no longer have an original, continuous flow from source to outlet. The presence of weirs and dams has altered ...habitats, thus affecting the wildlife that lives within them. This is especially true for migrating rheophilic fish species, which, in addition to safe passage, depend on gradient and fast‐flowing waters for reproductive success and early development.
Thus far, research has focused on investigating the impacts of weirs and dams on fish passage, with less attention paid to the loss of habitat entrained by such infrastructure. The loss of rheophilic habitat is particularly important in lowland streams, where gradient is limited, and dams and weirs can be constructed with less effort.
Denmark is considered a typical lowland country, where the landscape around streams and rivers has been modified by agriculture and other human activities for centuries, leaving management practitioners wondering how much change is acceptable to maintain sustainable fish populations and fisheries practices.
With examples from Denmark, this paper attempts to conceptualize the loss in habitat as a result of barriers in lowland streams and rivers, and the repercussions that such alterations may have on rheophilic fish populations. Furthermore, the need for management to address habitat loss and its related consequences concurrently with the improvement of fish passage is emphasized.
Research is a key element of any profession and an analysis of published research enables professional communities to understand the dynamics of growth in a profession and its literature. ...Bibliometrics is used to carry out the analysis of Library and Information Science (LIS) research articles published by Pakistani authors because it is an important method for measuring impact of published research. We used relatedness measures to estimate the correlation among research growth, authorship patterns and publishing outlets. The sample consists of the research articles published during 2001–2016 by Pakistani authors who mostly remained associated with Pakistani institutions during this period. Chi-square and Binary Logistic Regression was used to find the relationship among different research indicators. Overall annual growth rate of the research articles remained between 8 and 9% from 2004 to 2016. During 2001 and 2016, 166 Pakistani authors contributed 600 articles with an average of 3.61 articles per author. Growth of articles published in foreign journals remained higher as compared to local journals. Out of 600 articles, 31% were contributed by 48 female and 71% articles were published by 118 male authors. Females were slightly more productive with an average of 3.85 than males with an average of 3.51. Collaboration among authors was seven times higher during 2009–16. Collaboration was higher among practitioners and for impact factor publishing. Females contributed more research during 2009–16 as compared to 2001–08. During the 2009–16, foreign articles were contributed with higher percentage by females and faculty. The current study depicts a comprehensive picture of LIS research publishing by Pakistani authors while exploring relationships among different bibliometric indicators.
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