scholarly journals Regional analysis of multivariate compound coastal flooding potential around Europe and environs: sensitivity analysis and spatial patterns

2021 ◽  
Vol 21 (7) ◽  
pp. 2021-2040
Author(s):  
Paula Camus ◽  
Ivan D. Haigh ◽  
Ahmed A. Nasr ◽  
Thomas Wahl ◽  
Stephen E. Darby ◽  
...  
Keyword(s):  
Time Window ◽  
North Atlantic Ocean ◽  
Regional Analysis ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Northern Coast ◽  
The North ◽  
Run Off ◽  
Kendall Rank Correlation ◽  
Driver Assessment

Abstract. In coastal regions, floods can arise through a combination of multiple drivers, including direct surface run-off, river discharge, storm surge, and waves. In this study, we analyse compound flood potential in Europe and environs caused by these four main flooding sources using state-of-the-art databases with coherent forcing (i.e. ERA5). First, we analyse the sensitivity of the compound flooding potential to several factors: (1) sampling method, (2) time window to select the concurrent event of the conditioned driver, (3) dependence metrics, and (4) wave-driven sea level definition. We observe higher correlation coefficients using annual maxima than peaks over threshold. Regarding the other factors, our results show similar spatial distributions of the compound flooding potential. Second, the dependence between the pairs of drivers using the Kendall rank correlation coefficient and the joint occurrence are synthesized for coherent patterns of compound flooding potential using a clustering technique. This quantitative multi-driver assessment not only distinguishes where overall compound flooding potential is the highest, but also discriminates which driver combinations are more likely to contribute to compound flooding. We identify that hotspots of compound flooding potential are located along the southern coast of the North Atlantic Ocean and the northern coast of the Mediterranean Sea.

scholarly journals Regional analysis of multivariate compound flooding potential: sensitivity analysis and spatial patterns

2021 ◽  
Author(s):  
Paula Camus ◽  
Ivan D. Haigh ◽  
Ahmed Nasr ◽  
Thomas Wahl ◽  
Stephen E. Darby ◽  
...  
Keyword(s):  
Time Window ◽  
North Atlantic Ocean ◽  
Regional Analysis ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Northern Coast ◽  
The North ◽  
Run Off ◽  
Driver Assessment ◽  
Joint Occurrence

Abstract. In coastal regions, floods can arise through a combination of multiple drivers, including direct surface run- off, river discharge, storm surge and waves. In this study, we analyse compound flood potential in Europe caused by these four main flooding sources using state-of-the-art databases with homogenous forcing (i.e., ERA5). First, we perform an analysis to assess the sensitivity of the compound flooding potential to several factors: 1) sampling method; 2) time window to select the concurrent event of the conditioned driver; 3) dependence metrics; 4) wave-driven sea level definition. We observe higher correlation coefficients using annual maxima than peaks over threshold. Regarding the other factors, our results show similar spatial distributions of the compound flooding potential. Second, the dependence between the pairs of drivers using the Kendall's rank correlation coefficient and the joint occurrence are synthesized for coherent patterns of compound flooding potential using a clustering technique. This quantitative multi-driver assessment not only distinguishes where overall compound flooding potential is the highest, but also discriminates which driver combinations are more likely to contribute to compound flooding. We identify hotspots of compound flooding potential located along the southern coast of the North Atlantic Ocean and the northern coast of the Mediterranean Sea.

Benthic Invertebrate Fauna and Feeding Relationships of Brown Trout, Salmo trutta Linnaeus, and River Blackfish, Gadopsis marmoratus Richardson, in the Aberfeldy River, Victoria

1978 ◽  
Vol 29 (6) ◽  
pp. 725 ◽  
Author(s):  
PD Jackson
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Benthic Invertebrate ◽  
Invertebrate Fauna ◽  
Kendall Rank Correlation ◽  
Brown Trout Salmo Trutta

The benthic invertebrate fauna and the stomachs of brown trout and river blackfish in a section of the Aberfeldy River, Victoria, were sampled regularly from October 1971 to November 1972. The ranges of food organisms utilized by the two species were very similar as were the proportions of the different food categories. Kendall rank correlation coefficients indicated that the diets of the two fishes were similar on all but the July sampling date. Due to apparent differences in habitat prefer- ences this similarity in diets may be regarded as giving rise to indirect competition.

scholarly journals Estimating Contemporary and Future Wind-Damage Losses from Hurricanes Affecting Eglin Air Force Base, Florida

2011 ◽  
Vol 50 (7) ◽  
pp. 1514-1526 ◽  
Author(s):  
James B. Elsner ◽  
Shawn W. Lewers ◽  
Jill C. Malmstadt ◽  
Thomas H. Jagger
Keyword(s):  
Gulf Of Mexico ◽  
Air Force ◽  
North Atlantic Ocean ◽  
Wind Damage ◽  
Northern Coast ◽  
Wind Fields ◽  
The North ◽  
Extreme Wind ◽  
Extreme Wind Speed ◽  
Air Force Base

AbstractThe strongest hurricanes over the North Atlantic Ocean are getting stronger, with the increase related to rising ocean temperature. Here, the authors develop a procedure for estimating future wind losses from hurricanes and apply it to Eglin Air Force Base along the northern coast of Florida. The method combines models of the statistical distributions for extreme wind speed and average sea surface temperature over the Gulf of Mexico with dynamical models for tropical cyclone wind fields and damage losses. Results show that the 1-in-100-yr hurricane from the twentieth century picked at random to occur in the year 2100 would result in wind damage that is 36% [(13%, 76%) = 90% confidence interval] greater solely as a consequence of the projected warmer waters in the Gulf of Mexico. The method can be applied elsewhere along the coast with modeling assumptions modified for regional conditions.

Feeding relationships of galaxiids, bullies, eels and trout in a New Zealand river

1975 ◽  
Vol 26 (3) ◽  
pp. 299 ◽  
Author(s):  
PL Cadwallader
Keyword(s):  
New Zealand ◽  
Native Species ◽  
Salmo Trutta ◽  
Relative Proportion ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Food Type ◽  
Kendall Rank Correlation ◽  
Direct Competition ◽  
Brown Trout Salmo Trutta

The feeding relationships of the common river galaxias, Galaxias vulgaris Stokell, upland bully, Gobiomorphus breviceps (Stokell), long-finned eel, Anguilla diefenbachii Gray, short-finned eel, A. australis schmidtii Phillipps, and brown trout, Salmo trutta L., were examined in the Glentui River, Canterbury, New Zealand, in February, May and November 1971. With few exceptions, the same food organisms were utilized by all species, but the relative proportion of each food type in the diet varied between species. Kendall rank correlation coefficients indicated that the diets of native fish were dissimilar, with the exception of galaxiids and bullies in May, but in six out of nine comparisons involving the introduced trout, the coefficients indicated varying degrees of similarity with the diets of the native species. Since their feeding mechanisms and feeding localities are different, similarities in the diets of eels and trout, trout and bullies, and bullies and galaxiids can be regarded as giving rise to indirect competition. However, since trout (C 200 mm long) and galaxiids occupy the same microhabitat and feed in the same manner, similarity in their diets can be regarded as giving rise to direct competition. Such direct competition for food, combined with interspecific aggression and similar microhabitat requirements, may help to explain the reduction in abundance of other galaxiids in areas in which trout have been introduced.

scholarly journals COMPARATIVE ANALYSIS OF NO-REFERENCE MEASURES FOR DIGITAL IMAGE SHARPNESS ASSESSMENT

Doklady BGUIR ◽  
2019 ◽  
pp. 113-120
Author(s):  
Y. I. Golub ◽  
F. V. Starovoitov ◽  
V. V. Starovoitov
Keyword(s):  
Digital Image ◽  
Digital Images ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Poor Quality ◽  
Image Sharpness ◽  
Control Stage ◽  
Kendall Rank Correlation ◽  
Distribution Parameters ◽  
Blurred Images

Recently, problems of digital image sharpness determination are becoming more relevant and significant. The number of digital images used in many fields of science and technology is growing. Images obtained in various ways may have unsatisfactory quality; therefore, an important step in image processing and analysis algorithms is a quality control stage of the received data. Poor quality images can be automatically deleted. In this article we study the problem of the automatic sharpness evaluation of digital images. As a result of the scientific literature analysis, 28 functions were selected that are used to analyze the clarity of digital images by calculation local estimates. All the functions first calculate local estimates in the neighborhood of every pixel, and then use the arithmetic mean as a generalized quality index. Testing have demonstrated that many estimates of local sharpness of the image often have abnormal distribution of the data. Therefore, some modified versions of the studied functions were additionally evaluated, instead of the average of local estimates, we studied the Weibull distribution parameters (FORM, SCALE, MEAN weib, MEDIAN weib). We evaluated three variants of the correlation of quantitative sharpness assessments with the subjective assessments of human experts. Since distribution of local features is abnormal, Spearman and Kendall rank correlation coefficients were used. Correlation above 0.7 means good agreement between quantitative and visual estimates. The experiments were carried out on digital images of various quality and clarity: artificially blurred images and blurred during shooting. Summing up results of the experiments, we propose to use seven functions for automatic analysis of the digital image sharpness, which are fast calculated and better correlated with the subjective sharpness evaluation.

scholarly journals 1048 Evaluation of mitral annular disjunction in mitral valve prolapse: is echo imaging enough?

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
V Mantegazza ◽  
L Fusini ◽  
P Gripari ◽  
V Volpato ◽  
G Italiano ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Imaging Techniques ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Mitral Annulus ◽  
Left Ventricular ◽  
Atrial Wall ◽  
Kendall Rank Correlation ◽  
Kendall’S Τ

Abstract Funding Acknowledgements None Background The separation between the atrial wall-mitral valve (MV) junction and the left ventricular (LV) attachment (mitral annulus disjunction, MAD) is a recently discovered feature linked to MV prolapse (MVP). It is associated to higher complexity of MV lesions and is possibly responsible for mechanically induced fibrosis of the LV inferobasal wall and consequently for malignant ventricular events. MAD has been described in different studies evaluating the MV either by transthoracic (TTE) or transoesophageal (TOE) echocardiography or by cardiac magnetic resonance (CMR). Purpose The aim of the present study was to assess MAD and compare the ability of identifying and localizing MAD with different imaging techniques in a cohort of patients with MVP and severe mitral regurgitation eligible for surgery. Methods A total of 108 patients with MVP requiring surgery and undergoing CMR and TTE were enrolled in the study. Ninety of them underwent also intraoperative TOE. MAD was defined as any distance observed between the atrial wall-MV junction and the LV wall at end-systole. It was retrospectively assessed in the long axis views (4-, 3-, 2-chamber) and compared between the 3 imaging techniques. Results MAD was identified in 18 out of 108 patients at TTE (16.7%), in 15 among 90 patients undergoing TOE (16.7%) and in 42 patients at CMR (38.9%). Comparing data per patient regardless of MAD localization, a good correlation in identifying MAD was obtained between TTE and TOE (Kendall’s τ coefficient 0.83, p < 0.001); a lower but still significant correlation was observed between TTE and CMR (τ coefficient 0.46, p < 0.001) and between TOE and CMR (τ coefficient 0.39, p < 0.001). Higher Kendall rank correlation coefficients were obtained comparing data per view (TTE vs. TOE: τ coefficient 0.86, p < 0.001; TTE vs. CMR: τ coefficient 0.48, p < 0.001; TOE vs. CMR: τ coefficient 0.42, p < 0.001). Considering only patients with MAD (Figure 1), the agreement rate between TTE and TOE (14 patients) in identifying MAD in the same view was 95%, whereas a lower agreement was observed between TTE and CMR (79% in 16 patients) and between TOE and CMR (67% in 13 patients). MAD measured 7.5 ± 1.9 mm at TTE, 6.3 ± 1.7 mm at TOE and 6.9 ± 3.4 mm at CMR. Conclusion In surgical MVP patients, MAD showed a higher prevalence at CMR and a lower detection rate by echo imaging. Therefore, an integrated imaging approach could be necessary in the evaluation of MVP. This relatively mild separation of the atrial wall-MV junction and LV myocardium may probably be better recognized by CMR due to a higher spatial resolution. Echo is fundamental for the anatomic and haemodynamic characterization of the valvulopathy by itself, while CMR may better define MAD and myocardial fibrosis helping the physician in identifying PVM patients with higher arrhythmic risk independent of mitral regurgitation grade. Abstract 1048 Figure 1

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