The role of extremity of summer floods for the annual statistic

2020 ◽  
Author(s):  
Svenja Fischer ◽  
Andreas Schumann
Keyword(s):  
Large River ◽  
Dam Failure ◽  
Deterministic Models ◽  
Annual Series ◽  
Weather Patterns ◽  
Catchment Size ◽  
Heavy Tailed ◽  
Flood Generation ◽  
The Impact

<p>Within the annual maximum series (AMS), which is the basis for assessing most of the flood protection measurements, summer as well as winter flood events are included. However, these do not only differ in their flood generation but also in their statistical distribution. While the distribution of winter floods is mostly light-tailed, summer floods often show a heavy-tailed behaviour. A light-tailed behaviour leads to a bounded distribution, which means that winter floods cannot exceed a certain magnitude. Heavy-tailed distributions are unbounded and extrapolation to annualities of several hundred years can lead to infinitely large design floods.  A combination of these different tail behaviours in the AMS often leads to heavy-tail behaviour for the annual series. In a study of the large river basins of Rhine, Danube and Elbe we investigate the impact of summer floods on the AMS. Spatial patterns become visible that can be linked to weather patterns like Vb. Moreover, an impact of the catchment size can be seen, where larger catchments tend to have lighter tailed distributions and a smaller impact of summer floods.  The results are then compared concerning their causality using deterministic models that include dam failure and inundation and the role of tributaries is shown.</p>

scholarly journals Role of Near-Inertial Internal Waves in Subthermocline Diapycnal Mixing in the Northern Gulf of Mexico

2015 ◽  
Vol 45 (12) ◽  
pp. 3137-3154 ◽  
Author(s):  
Zhao Jing ◽  
Ping Chang ◽  
Steven F. DiMarco ◽  
Lixin Wu
Keyword(s):  
Gulf Of Mexico ◽  
Hurricane Katrina ◽  
Internal Waves ◽  
Dominant Role ◽  
Deep Ocean ◽  
Diapycnal Mixing ◽  
Northern Gulf Of Mexico ◽  
Weather Patterns ◽  
The Impact

AbstractMoored ADCP data collected in the northern Gulf of Mexico are analyzed to examine near-inertial internal waves and their contribution to subthermocline diapycnal mixing based on a finescale parameterization of deep ocean mixing. The focus of the study is on the impact of near-inertial internal waves generated by an extreme weather event—that is, Hurricane Katrina—and by month-to-month variation in weather patterns on the diapycnal mixing. The inferred subthermocline diapycnal mixing exhibits pronounced elevation in the wake of Katrina. Both the increased near-inertial (0.8–1.8f, where f is the Coriolis frequency) and superinertial (>1.8f) shear variances contribute to the elevated diapycnal mixing, but the former plays a more dominant role. The intense wind work on near-inertial motions by the hurricane is largely responsible for the energetic near-inertial shear variance. Energy transfer from near-inertial to superinertial internal waves, however, appears to play an important role in elevating the superinertial shear variance. The inferred subthermocline diapycnal mixing in the region also exhibits significant month-to-month variation with the estimated diffusivity in January 2006 about 3 times the values in November and December 2005. The subseasonal change in the diapycnal mixing mainly results from the subseasonal variation of the near-inertial wind work that causes intensification of the near-inertial shear in January 2006.

scholarly journals Analysis of persistence in the flood timing and the role of catchment wetness on flood generation in a large river basin in India

2019 ◽  
Vol 139 (1-2) ◽  
pp. 373-388 ◽  
Author(s):  
Poulomi Ganguli ◽  
Yamini Rama Nandamuri ◽  
Chandranath Chatterjee
Keyword(s):  
River Basin ◽  
Large River ◽  
Flood Generation

scholarly journals The Role of Twitter Medium in Business with Regression Analysis and Statistical Modelling

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jia Cong ◽  
Zubair Ahmad ◽  
Basim S.O. Alsaedi ◽  
Osama Abdulaziz Alamri ◽  
Ibrahim Alkhairy ◽  
...  
Keyword(s):  
Positive Impact ◽  
Statistical Tests ◽  
Statistical Modelling ◽  
Proposed Model ◽  
Media Platform ◽  
Heavy Tailed ◽  
Linear Regression Modeling ◽  
The Impact ◽  
A Company

Marketing refers to the strategies a company undertakes to promote its brands to its potential audience. Advertising provides useful venues for marketing to promote a company’s survives/goods to the audience. It has a positive impact on the sale of services or products. In this study, we consider a well-known online medium called Twitter (the fourth most popular social media platform used by marketers) to check its impact on sales. For this purpose, the simple linear regression modeling approach is implemented to test the significance and usefulness of Twitter advertising on sale. Statistical tests such as t-test and correlation test are adopted to test the hypothesis of the “impact of Twitter advertising on sales.” Based on the findings of this study, it is observed that Twitter advertising has a positive impact on sales. Furthermore, a new statistical model called the exponential T-X exponentiated exponential is introduced. The proposed model is very interesting and possesses heavy-tailed characteristics which are useful in finance and other related sectors. Finally, the applicability of the new model is illustrated by considering the sales data.

Controls on microplastic flux mechanisms in a large river

2020 ◽  
Author(s):  
Freija Mendrik ◽  
Daniel Parsons ◽  
Christopher Hackney ◽  
Cath Waller ◽  
Vivien Cumming ◽  
...  
Keyword(s):  
Mekong Delta ◽  
Large River ◽  
Field Investigation ◽  
Population Increase ◽  
Plastic Pollution ◽  
Source To Sink ◽  
Tonle Sap ◽  
Vertical Velocity Profile ◽  
The Impact

<p>The majority of marine plastic pollution originates from land-based sources with the dominant transport agent being riverine. Despite many of the potential ecotoxicological consequences of plastics being well known, research has only just recently begun to explore the source to sink dynamics of plastics in the environment. Despite the widespread recognition that rivers dominate the global flux of plastics to the ocean, there is a key knowledge gap regarding the nature of the flux, the behaviour of microplastics (<5mm) in transport and its pathways from rivers into the ocean. Additionally, little is presently known about the role of biota in the transport of microplastics through processes such as biofilm formation and how this influences microplastic fate. This prevents progress in understanding microplastic fate and hotspot formation, as well as curtailing the evolution of effective mitigation and policy measures.</p><p> </p><p>As part of the National Geographic Rivers of Plastic project, a combined-laboratory and field investigation was conducted. Fieldwork was undertaken in the Mekong River, one of the top global contributors to marine plastic pollution with an estimated 37,000 tonnes of plastic being discharged from the Mekong Delta each year. This flux is set to grow significantly in accordance with the projected population increase in the basin. The results presented herein outline a suite of laboratory experiments that explore the role of biofilms on the generation of microplastic flocs and the impact on buoyancy and settling velocities. Aligned fieldwork details the particulate flux and transport of microplastic, throughout the vertical velocity profile, across the river-delta-coast system, including the Tonle Sap Lake. The results also highlight potential areas of highest ecological risk related to the dispersal and distribution of microplastics. Finally, pilot data on the levels of microplastics within fish from the Mekong system are also quantified to explore the potential impact of biological uptake on the fate and sinks of plastics within the system.</p>

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

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