scholarly journals A simple model of runoff from ungauged basins in West Greenland

1982 ◽  
Vol 111 ◽  
pp. 1-26
Author(s):  
R.J Braithwaite
Keyword(s):  
Simple Model ◽  
Model Parameters ◽  
Precipitation Series ◽  
Ungauged Basins ◽  
West Greenland ◽  
Independent Variables ◽  
The World ◽  
Order Of Magnitude ◽  
Design Yield ◽  
Systematic Field

A simple model of runoff in West Greenland is proposed for the case that glaciers are in a state of balance. The independent variables in the model are estimated annual precipitation and evaporation while model parameters are evaluated by analyses of precipitation series from Greenland, and mass balance series from other parts of the world. The model ean be applied to ungauged basins for preliminary calculations of mean mnoff, reservoir capacities and relative error in mean runoff. Application of the model to sixteen proposed hydropower projects in West Greenland shows an order-of-magnitude agreement with earlier estimates. However, a more detailed analysis of runoff from Johan Dahl Land confirms that the mnoff there is less than originally estimated. The proposed reservoir appears to be adequate for 30-year storage but the design yield of the project must be reduced for safety. The shortcomings of the model should be obvious. They ean be best overcorne by an improved knowledge of hydrological conditions in the country resulting from systematic field observations.

scholarly journals Wealth Rheology

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 842
Author(s):  
Zdzislaw Burda ◽  
Malgorzata J. Krawczyk ◽  
Krzysztof Malarz ◽  
Malgorzata Snarska
Keyword(s):  
Exchange Rate ◽  
Simple Model ◽  
Real Data ◽  
Ranking List ◽  
Kendall’S Τ ◽  
The World ◽  
The Usa ◽  
Overlap Ratio ◽  
Growth Volatility ◽  
Wealth Rank

We study wealth rank correlations in a simple model of macroeconomy. To quantify rank correlations between wealth rankings at different times, we use Kendall’s τ and Spearman’s ρ, Goodman–Kruskal’s γ, and the lists’ overlap ratio. We show that the dynamics of wealth flow and the speed of reshuffling in the ranking list depend on parameters of the model controlling the wealth exchange rate and the wealth growth volatility. As an example of the rheology of wealth in real data, we analyze the lists of the richest people in Poland, Germany, the USA and the world.

Investigations of Tail and Defect States in a-Si0.6Ge0.4:H Alloys by PDS and ESR - Implications for the Interaction of Weak and Dangling Bonds

1995 ◽  
Vol 377 ◽  
Author(s):  
Tilo P. Drüsedau ◽  
Andreas N. Panckow ◽  
Bernd Schröder
Keyword(s):  
Silicon Germanium ◽  
Defect Density ◽  
State Density ◽  
Model Parameters ◽  
Defect States ◽  
Conversion Model ◽  
Order Of Magnitude ◽  
Underlying Mechanisms ◽  
Amorphous Silicon Germanium ◽  
Excess Absorption

ABSTRACTInvestigations on the gap state density were performed on a variety of samples of hydrogenated amorphous silicon germanium alloys (Ge fraction around 40 at%) containing different amounts of hydrogen. From subgap absorption measurements the values of the “integrated excess absorption” and the “defect absorption” were determined. Using a calibration constant, which is well established for the determination of the defect density from the integrated excess absorption of a-Si:H and a-Ge:H, it was found that the defect density is underestimated by nearly one order of magnitude. The underlying mechanisms for this discrepancy are discussed. The calibration constants for the present alloys are determined to 8.3×1016 eV−1 cnr2 and 1.7×1016 cm−2 for the excess and defect absorption, respectively. The defect density of the films was found to depend on the Urbach energy according to the law derived from Stutzmann's dangling bond - weak bond conversion model for a-Si:H. However, the model parameters - the density of states at the onset of the exponential tails N*=27×1020 eV−1 cm−3 and the position of the demarcation energy Edb-E*=0.1 eV are considerably smaller than in a-Si:H.

scholarly journals A Model of the International Monetary System*

2017 ◽  
Vol 133 (1) ◽  
pp. 295-355 ◽  
Author(s):  
Emmanuel Farhi ◽  
Matteo Maggiori
Keyword(s):  
Simple Model ◽  
Gold Standard ◽  
Supply And Demand ◽  
International Monetary System ◽  
Rate System ◽  
Monetary System ◽  
The World ◽  
The Common ◽  
Triffin Dilemma ◽  
World Supply

AbstractWe propose a simple model of the international monetary system. We study the world supply and demand for reserve assets denominated in different currencies under a variety of scenarios: a hegemon versus a multipolar world; abundant versus scarce reserve assets; and a gold exchange standard versus a floating rate system. We rationalize the Triffin dilemma, which posits the fundamental instability of the system, as well as the common prediction regarding the natural and beneficial emergence of a multipolar world, the Nurkse warning that a multipolar world is more unstable than a hegemon world, and the Keynesian argument that a scarcity of reserve assets under a gold standard or at the zero lower bound is recessionary. Our analysis is both positive and normative.

Development of an Inverse Plume Model for Mass Eruption Rate in Unsteady Conditions

2021 ◽  
Author(s):  
Stephen A Solovitz
Keyword(s):  
Laboratory Data ◽  
Model Performance ◽  
Volcanic Eruptions ◽  
Reynolds Numbers ◽  
Model Parameters ◽  
Plume Height ◽  
Eruption Rate ◽  
Mass Eruption Rate ◽  
Downstream Effects ◽  
Order Of Magnitude

Abstract Following volcanic eruptions, forecasters need accurate estimates of mass eruption rate (MER) to appropriately predict the downstream effects. Most analyses use simple correlations or models based on large eruptions at steady conditions, even though many volcanoes feature significant unsteadiness. To address this, a superposition model is developed based on a technique used for spray injection applications, which predicts plume height as a function of the time-varying exit velocity. This model can be inverted, providing estimates of MER using field observations of a plume. The model parameters are optimized using laboratory data for plumes with physically-relevant exit profiles and Reynolds numbers, resulting in predictions that agree to within 10% of measured exit velocities. The model performance is examined using a historic eruption from Stromboli with well-documented unsteadiness, again providing MER estimates of the correct order of magnitude. This method can provide a rapid alternative for real-time forecasting of small, unsteady eruptions.

Predicting Source Water Quality Following Wildfires Using Hydrologic Modeling

2021 ◽  
Author(s):  
Katie Wampler ◽  
Kevin D. Bladon ◽  
Monireh Faramarzi
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Carbon ◽  
The United States ◽  
First Year ◽  
Model Parameters ◽  
Source Water ◽  
Forested Watersheds ◽  
Field Samples ◽  
The World

<p>Forested watersheds are critical sources of the majority of the world’s drinking water. Almost one-third of the world’s largest cities and two-thirds of cities in the United States (US) rely on forested watersheds for their water supply. These forested regions are vulnerable to the increasing incidence of large and severe wildfires due to increases in regional temperatures and greater accumulation of fuels. When wildfires occur, increases in suspended sediment and organic carbon can negatively affect aquatic ecosystem health and create many costly challenges to the drinking water treatment process. These effects are often largest in the first year following a wildfire. While past research has shown the likelihood of source water impacts from wildfire, the magnitude of effects remains uncertain in most regions. In our study, we will quantify the projected short-term effects of three large (>70,000 ha) wildfires on key water quality parameters (sediment and organic carbon) in two important forested source watersheds in the Cascade Range of Oregon, US. We calibrated and validated a modified Soil and Water Assessment Tool (SWAT) to simulate streamflow, sediment loads and transport, as well as in-stream organic carbon processes for a historical period prior to wildfire. The calibrated model parameters were then modified based on literature values and burn severity maps to represent post-fire conditions of the three large wildfires. The parameter adjustments for simulating wildfire will be validated with post-fire water quality field samples from the wildfires. We will present estimations of future water quality impacts in the burned watersheds under different precipitation conditions at a daily scale for the first year following the wildfires, which will provide testable hypotheses. Additionally, we will determine catchment characteristics most critical in determining the post-fire water quality response. This work will help predict the magnitude of effects from these historic wildfires, which can inform forest and drinking water management decision making.</p>

scholarly journals A Bayesian ensemble data assimilation to constrain model parameters and land-use carbon emissions

2018 ◽  
Vol 15 (9) ◽  
pp. 2909-2930 ◽  
Author(s):  
Sebastian Lienert ◽  
Fortunat Joos
Keyword(s):  
Land Use ◽  
Carbon Emissions ◽  
Latin Hypercube Sampling ◽  
Historical Period ◽  
Model Parameters ◽  
Dynamic Global Vegetation Model ◽  
Order Of Magnitude ◽  
The Difference ◽  
Wood Harvest ◽  
Global Vegetation

Abstract. A dynamic global vegetation model (DGVM) is applied in a probabilistic framework and benchmarking system to constrain uncertain model parameters by observations and to quantify carbon emissions from land-use and land-cover change (LULCC). Processes featured in DGVMs include parameters which are prone to substantial uncertainty. To cope with these uncertainties Latin hypercube sampling (LHS) is used to create a 1000-member perturbed parameter ensemble, which is then evaluated with a diverse set of global and spatiotemporally resolved observational constraints. We discuss the performance of the constrained ensemble and use it to formulate a new best-guess version of the model (LPX-Bern v1.4). The observationally constrained ensemble is used to investigate historical emissions due to LULCC (ELUC) and their sensitivity to model parametrization. We find a global ELUC estimate of 158 (108, 211) PgC (median and 90 % confidence interval) between 1800 and 2016. We compare ELUC to other estimates both globally and regionally. Spatial patterns are investigated and estimates of ELUC of the 10 countries with the largest contribution to the flux over the historical period are reported. We consider model versions with and without additional land-use processes (shifting cultivation and wood harvest) and find that the difference in global ELUC is on the same order of magnitude as parameter-induced uncertainty and in some cases could potentially even be offset with appropriate parameter choice.

scholarly journals Estimation of baseflow parameters of variable infiltration capacity model with soil and topography properties for predictions in ungauged basins

2011 ◽  
Vol 8 (4) ◽  
pp. 7017-7053 ◽  
Author(s):  
Z. Bao ◽  
J. Liu ◽  
J. Zhang ◽  
G. Fu ◽  
G. Wang ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Model Simulation ◽  
Parameters Estimation ◽  
Model Parameters ◽  
Ungauged Basins ◽  
Variable Infiltration Capacity ◽  
Infiltration Capacity ◽  
Ungauged Catchments ◽  
Vic Model ◽  
Predictions In Ungauged Basins

Abstract. Equifinality is unavoidable when transferring model parameters from gauged catchments to ungauged catchments for predictions in ungauged basins (PUB). A framework for estimating the three baseflow parameters of variable infiltration capacity (VIC) model, directly with soil and topography properties is presented. When the new parameters setting methodology is used, the number of parameters needing to be calibrated is reduced from six to three, that leads to a decrease of equifinality and uncertainty. This is validated by Monte Carlo simulations in 24 hydro-climatic catchments in China. Using the new parameters estimation approach, model parameters become more sensitive and the extent of parameters space will be smaller when a threshold of goodness-of-fit is given. That means the parameters uncertainty is reduced with the new parameters setting methodology. In addition, the uncertainty of model simulation is estimated by the generalised likelihood uncertainty estimation (GLUE) methodology. The results indicate that the uncertainty of streamflow simulations, i.e., confidence interval, is lower with the new parameters estimation methodology compared to that used by original calibration methodology. The new baseflow parameters estimation framework could be applied in VIC model and other appropriate models for PUB.

scholarly journals A very simple model to account for the rapid rise of the British variant of SARS-CoV-2 in several countries and the world

2021 ◽  
Author(s):  
Hugo Fort
Keyword(s):  
Simple Model ◽  
Evolutionary Model ◽  
Single Parameter ◽  
Rapid Rise ◽  
The World ◽  
The Uk

Since its first detection in the UK in September 2020, a highly contagious version of the coronavirus, called the British variant or B.1.1.7 SARS-CoV-2 virus lineage, is rapidly spreading across several countries and becoming the dominant strain in the outbreak. Here it is shown that a very simple evolutionary model, when including the latest available data from March 2021, can fit the observed change in frequency of B.1.1.7 for several countries, regions of countries and the whole world with a single parameter which is almost universal.

scholarly journals Scleractinian corals from the Upper Cretaceous and Lower Tertiary of Nûgssuaq, West Greenland

1972 ◽  
Vol 100 ◽  
pp. 1-132
Author(s):  
S Floris
Keyword(s):  
Upper Cretaceous ◽  
Reef Coral ◽  
Conclusive Evidence ◽  
New Genera ◽  
Generic Level ◽  
West Greenland ◽  
North West ◽  
Fossil Corals ◽  
The World ◽  
Marine Fossils

Localities and deposits in north-west Nûgssuaq yielding fossil corals of the order Scleractinia are described. The age of the corals is Campanian?, Maastrichtian and Lower Paleocene (Danian), on the basis of other marine fossils. 22 species are considered; 7 are described as new and are indigenous, 2 are possibly North American forms, 3 are known from Europe, and 10 are identifiable only to generic level. The following genera and subgenera are represented: Haimesiastraea (Haimesiastraea), H. (Perupiastrea)?, Discotrochus?, Astrangia (Coenangia)?, Oculina, Caryophyllia, Trochocyathus, Paracyathus, Stephanocyathus (Stephanocyathus), Desmophyllum?, Lophelia?, Parasmilia, Flabellum, Balanophyllia, and Dendrophyllia . In addition, two new genera are described: Kangiliacyathus and Faksephyllia . Certain Danian corals from Scandinavia are also revised. In a survey of habitats, the lithology of the corallocalities is considered together with bathymetric and thermal ranges known for scleractinian genera and species from other parts of the world. Depth and temperature of the Campanian and Maastrichtian seas in Greenland cannot be estimated with any accuracy. The Lower and Upper Danian seas were generally rather shallow. There is little evidence on which to judge the Danian climate. Two species were perhaps hermatypic (no reef structures have been found). The remaining scleractinians are presumed to have been ahermatypic. A non-reef coral association has been found. Lower Danian rather sparsely populated polytypic coral thickets show signs of continual disturbance from water turbulence. The approximate depth of formation of these thickets appears to have been 80 m or shallower, which appears to be less than is usual for coral structures of this type. Some Lower Paleocene species provide conclusive evidence of a direct connection between the Danian seas of West Greenland and of Scandinavia.

scholarly journals PERINATAL AND INFANT MORTALITY IN THE TRANSCARPATHIAN REGION AND UKRAINE AGAINST THE BACKGROUND OF THE EUROPEAN UNION AND THE WORLD: A COMPARATIVE ANALYSIS AND POSSIBLE PROBLEMS

2020 ◽  
Vol 73 (3) ◽  
pp. 603-608
Author(s):  
Ivan M. Rogach ◽  
Gennady O. Slabkiy ◽  
Renata Y. Pogorilyak ◽  
Angelika O. Keretsman ◽  
Ivan I. Gadzhega
Keyword(s):  
Perinatal Mortality ◽  
Medical Information ◽  
The European Union ◽  
European Database ◽  
The World ◽  
Regional Medical ◽  
Order Of Magnitude ◽  
Economic Institute ◽  
The University ◽  
The Eu

The aim of this article was to analyze the dynamics of perinatal mortality and mortality up to 1 year in the Transcarpathian region and Ukraine in comparison with other countries of Europe and the world. Materials and methods: The study is based on data from the Transcarpathian Regional Medical Information and Analytical Center, the Center for Medical Statistics of the Ministry of Health of Ukraine, the European database «Health for All» and the Center for Research of Health Services at the University of Kent, Kiev Economic Institute of the Kiev School of Economics (July 2017). Review: In 2016, mortality under the age of 1 year in Ukraine amounted to 7.4 per 1000 live births, which is 13.5% lower than the same indicator in 2012 (8.4). According to perinatal mortality, in Ukraine this indicator has a level of 8.59 ‰, while the average in the EU countries does not exceed 6.01 ‰. Conclusions: Perinatal and mortality rates up to 1 year in the Transcarpathian region, as in Ukraine as a whole, are an order of magnitude higher than the European average. The same negative trend in the survival of newborns in Transcarpathia and in Ukraine.

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