scholarly journals An alternative approach to estimate any subdaily extreme of rainfall and wind from usually available records

Author(s):  
José M. Pérez-Bella ◽  
Javier Domínguez-Hernández ◽  
Juan E. Martínez-Martínez ◽  
Mar Alonso-Martínez ◽  
Juan J. del Coz-Díaz

AbstractA wide variety of engineering applications requires the use of maximum values of rainfall intensity and wind speed related to short recording intervals, which can often only be estimated from available less exhaustive records. Given that many locations lack exhaustive climatic records that would allow accurate empirical correlations between different recording intervals to be identified, generic equations are often used to estimate these extreme values. The accuracy of these generic estimates is especially important in fields such as the study of wind-driven rain, in which both climatic variables are combined to characterise the phenomenon. This work assesses the reliability and functionality of some of these most widespread generic equations, analysing climatic datasets gathered since 2008 in 109 weather stations in Spain and the Netherlands. Considering multiple recording intervals at each location, it is verified that most of these generic estimations, used especially in the study of wind-driven rain, have functional limitations and can cause significant errors when characterising both variables for subdaily intervals and extreme conditions. Finally, an alternative approach is proposed to accurately extrapolate extreme values of both variables related to any subdaily recording interval in a functional manner and from any available records.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1207
Author(s):  
Gonçalo C. Rodrigues ◽  
Ricardo P. Braga

This study aims to evaluate NASA POWER reanalysis products for daily surface maximum (Tmax) and minimum (Tmin) temperatures, solar radiation (Rs), relative humidity (RH) and wind speed (Ws) when compared with observed data from 14 distributed weather stations across Alentejo Region, Southern Portugal, with a hot summer Mediterranean climate. Results showed that there is good agreement between NASA POWER reanalysis and observed data for all parameters, except for wind speed, with coefficient of determination (R2) higher than 0.82, with normalized root mean square error (NRMSE) varying, from 8 to 20%, and a normalized mean bias error (NMBE) ranging from –9 to 26%, for those variables. Based on these results, and in order to improve the accuracy of the NASA POWER dataset, two bias corrections were performed to all weather variables: one for the Alentejo Region as a whole; another, for each location individually. Results improved significantly, especially when a local bias correction is performed, with Tmax and Tmin presenting an improvement of the mean NRMSE of 6.6 °C (from 8.0 °C) and 16.1 °C (from 20.5 °C), respectively, while a mean NMBE decreased from 10.65 to 0.2%. Rs results also show a very high goodness of fit with a mean NRMSE of 11.2% and mean NMBE equal to 0.1%. Additionally, bias corrected RH data performed acceptably with an NRMSE lower than 12.1% and an NMBE below 2.1%. However, even when a bias correction is performed, Ws lacks the performance showed by the remaining weather variables, with an NRMSE never lower than 19.6%. Results show that NASA POWER can be useful for the generation of weather data sets where ground weather stations data is of missing or unavailable.


2016 ◽  
Vol 13 ◽  
pp. 151-161 ◽  
Author(s):  
Michael Borsche ◽  
Andrea K. Kaiser-Weiss ◽  
Frank Kaspar

Abstract. Hourly and monthly mean wind speed and wind speed variability from the regional reanalysis COSMO-REA6 is analysed in the range of 10 to 116 m height above ground. Comparisons with independent wind mast measurements performed between 2001 and 2010 over Northern Germany over land (Lindenberg), the North Sea (FINO platforms), and The Netherlands (Cabauw) show that the COSMO-REA6 wind fields are realistic and at least as close to the measurements as the global atmospheric reanalyses (ERA20C and ERA-Interim) on the monthly scale. The median wind profiles of the reanalyses were found to be consistent with the observed ones. The mean annual cycles of variability are generally reproduced from 10 up to 116 m in the investigated reanalyses. The mean diurnal cycle is represented qualitatively near the ground by the reanalyses. At 100 m height, there is little diurnal cycle left in the global and regional reanalyses, though a diurnal cycle is still present in the measurements over land. Correlation coefficients between monthly means of the observations and the reanalyses range between 0.92 at 10 m and 0.99 at 116 m, with a slightly higher correlation of the regional reanalyses at Lindenberg at 10 m height which is significant only at a lower than 95 % significance level. Correlations of daily means tend to be higher for the regional reanalysis COSMO-REA6. Increasing temporal resolution further, reduces this advantage of the regional reanalysis. At around 100 m, ERA-Interim yields a higher correlation at Lindenberg and Cabauw, whereas COSMO-REA6 yields a higher correlation at FINO1 and FINO2.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Farzad Arefi ◽  
Jamal Moshtagh ◽  
Mohammad Moradi

In the current work by using statistical methods and available software, the wind energy assessment of prone regions for installation of wind turbines in, Qorveh, has been investigated. Information was obtained from weather stations of Baneh, Bijar, Zarina, Saqez, Sanandaj, Qorveh, and Marivan. The monthly average and maximum of wind speed were investigated between the years 2000–2010 and the related curves were drawn. The Golobad curve (direction and percentage of dominant wind and calm wind as monthly rate) between the years 1997–2000 was analyzed and drawn with plot software. The ten-minute speed (at 10, 30, and 60 m height) and direction (at 37.5 and 10 m height) wind data were collected from weather stations of Iranian new energy organization. The wind speed distribution during one year was evaluated by using Weibull probability density function (two-parametrical), and the Weibull curve histograms were drawn by MATLAB software. According to the average wind speed of stations and technical specifications of the types of turbines, the suitable wind turbine for the station was selected. Finally, the Divandareh and Qorveh sites with favorable potential were considered for installation of wind turbines and construction of wind farms.


2020 ◽  
Vol 77 (8) ◽  
pp. 568-575 ◽  
Author(s):  
Sascha De Breij ◽  
Jana Mäcken ◽  
Jeevitha Yogachandiran Qvist ◽  
Daniel Holman ◽  
Moritz Hess ◽  
...  

ObjectivesPrevious research has shown that poor physical and mental health are important risk factors for early work exit. We examined potential differences in this association in older workers (50+) across educational levels.MethodsCoordinated analyses were carried out in longitudinal data sets from four European countries: the Netherlands (Longitudinal Aging Study Amsterdam), Denmark (Danish Longitudinal Study of Ageing), England (English Longitudinal Study of Ageing) and Germany (German Ageing Survey). The effect of poor self-rated health (SRH), functional limitations and depression on different types of early work exit (early retirement, economic inactivity, disability and unemployment) was examined using Cox regression analysis. We examined educational differences in these effects by testing interaction terms.ResultsPoor physical and mental health were more common among the lower educated. Poor SRH, functional limitations, and depression were all associated with a higher risk of early work exit. These health effects were strongest for the disability exit routes (poor SRH: HRs 5.77 to 8.14; functional limitations: HRs 6.65 to 10.42; depression: HRs 3.30 to 5.56). In the Netherlands (functional limitations) and England (functional limitations and SRH), effects were stronger in the lower educated.ConclusionsThe prevalence of health problems, that is, poor SRH, functional limitations and depression, was higher in the lower educated workers. All three health indicators increase the risk of early work exit. In some countries, health effects on early exit were stronger in the lower educated. Thus, lower educated older workers are an important target group for health policy and intervention.


1993 ◽  
Vol 57 (1) ◽  
pp. 147-152 ◽  
Author(s):  
B. Engel ◽  
P. Walstra

AbstractIn a dissection trial in The Netherlands two subpopulations were distinguished: gilts and castrated males. The sampling scheme, which emphasizes extreme values for the proportion of lean meat in the carcass, was followed for the two sexes separately, to ensure sufficient accuracy for a comparison between them. Significant differences between the prediction formulae for the lean meat proportion for the two sexes were found. Since it is not possible to use separate prediction formulae for the sexes in Dutch slaughterhouses, the formulae had to be combined into one overall prediction formula. In this paper it is shown how the separate prediction formulae for the sexes may be combined, utilizing additional data, not involving dissection, which were easily collected on the slaughterline, at little extra cost. The method can be extended to cover any number of subpopulations. Two objectives can be achieved at the same time: subpopulations may be compared accurately on the basis of a stratified sample and from the results of the comparison an efficient, unbiased, overall prediction formula may be distilled.


Author(s):  
Rambod Rayegan ◽  
Yong X. Tao ◽  
Frank Y. Fang

This study utilizes two sets of wind speed data at 3 m above the ground surface level retrieved from two on-campus weather stations to study the wind power generating potential at the University of North Texas Campus. Weather stations have been installed approximately 5 miles away from each other. The mean wind speed data of 10 minute intervals in a one-year period from February 1st 2011 to January 31st 2012 has been adopted and analyzed. The numerical values of the dimensionless Weibull shape parameter (k) and Weibull scale parameter (c) have been determined. Monthly average wind speed and standard deviation, power generation, and power density at the sensor level for both locations has been discussed. Lower values of wind speed were found during summer months and higher during spring months. The results show that the wind power density in the area is fair enough to be considered as a renewable power source for the University. Thereafter annual energy production by using two wind turbines with nominal capacities of 100 and 3.5 kW for both weather stations has been studied. Initial costs of using each turbine to maintain power demands of selected buildings have been compared. In order to utilize wind energy, it is recommended to install highly efficient wind turbines for electricity supply of campus buildings with lower power demands. Using grant monies to maintain the initial costs of the installation of wind turbines make them economically more desirable. Since wind power potential is low during summer, PV panels as proper supplements to the power generating system are suggested.


2018 ◽  
Vol 10 (12) ◽  
pp. 4589 ◽  
Author(s):  
Lei Tian ◽  
Jiming Jin ◽  
Pute Wu ◽  
Guo-yue Niu

Climatic elasticity is a crucial metric to assess the hydrological influence of climate change. Based on the Budyko equation, this study performed an analytical derivation of the climatic elasticity of evapotranspiration (ET). With this derived elasticity, it is possible to quantitatively separate the impacts of precipitation, air temperature, net radiation, relative humidity, and wind speed on ET in a watershed. This method was applied in the Wuding River Watershed (WRW), located in the center of the Yellow River Watershed of China. The estimated rate of change in ET caused by climatic variables is −10.69 mm/decade, which is close to the rate of change in ET (−8.06 mm/decade) derived from observable data. The accurate estimation with the elasticity method demonstrates its reliability. Our analysis shows that ET in the WRW had a significant downward trend, but the ET ratio in the WRW has increased continually over the past 52 years. Decreasing precipitation is the first-order cause for the reduction of ET, and decreasing net radiation is the secondary cause. Weakening wind speed also contributed to this reduction. In contrast, regional warming led to an increase in ET that partly offset the negative contributions from other climatic variables. Moreover, reforestation can affect the energy budget of a watershed by decreasing albedo, compensating for the negative influence of global dimming. The integrated effect from precipitation and temperature can affect the energy budget of a watershed by causing a large fluctuation in winter albedo.


2011 ◽  
Vol 7 (1) ◽  
pp. 31-46 ◽  
Author(s):  
Marc Hertogh

AbstractRecent surveys in the UK and the Netherlands indicate that there is widespread dissatisfaction with the justice system. But who are these ‘critics’ of the justice system? Most previous studies only produced general statistics, while the persons behind the figures remained invisible. By contrast, this article aims to put a face to these numbers and discusses two ways of analysing the profile of the critics. Based on a review of existing survey data, the article first looks at their ‘demographic profile’. Next, the article also considers a second, alternative, approach. Based on their level of legal awareness and legal identification, it distinguishes four different ‘normative profiles’: legalists, loyalists, cynics and outsiders. Moreover, the article shows how these normative profiles may be applied in future comparative studies on legal mobilisation and legal protest. It is concluded that combining both approaches will help us to look beyond common stereotypes and consider the critics of the justice system as real persons with genuine concerns about the administration of justice in their country.


Author(s):  
Elvira A. Islammagomedova ◽  
Eslanda A. Khalilova ◽  
Svetlana Ts. Kotenko ◽  
Aida A. Abakarova ◽  
Dinara A. Aliverdieva

The influence of extreme values of glucose and ethanol on the morphological properties of the yeast of the genus Saccharomyces was studied. The ability of strains S. cerevisiae Y-503, S. cerevisiae DAW-3a, and S. oviformis M-12X to adapt to stress was found. The dependence of the functional state and morphological properties of the studied strains on ploidy was shown. It was established that the cell forms of S. cerevisiae Y-503 and S. oviformis M-12X were diverse, the cells of the haploid strain S. cerevisiae DAW-3a were characterized by a round shape and smaller sizes compared to the polyploid strain Y-503 and diploid M-12X. Adaptation to different concentrations of glucose was accompanied by a change in the shape of the cells Y-503 and DAW-3a, while the sizes of cells were practically un-changed. Under conditions of simultaneous osmotic and ethanol stress in the cells of the studied strains, the presence of granular cytoplasm was revealed, which is associated with the accumulation of reserve nutrients. A change in the shape of the cells, form, surface, profile, color, size of colonies was detected. The study of the properties of the yeast of the genus Saccharomyces in the process of adaptation to extreme conditions may serve as the basis for the selection of strains that are promising for use in food biotechnology.


1996 ◽  
Vol 14 (10) ◽  
pp. 1088-1094 ◽  
Author(s):  
E. Cogliani ◽  
G. Abbate ◽  
S. Racalbuto

Abstract. Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987–1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues, throughout the year. A second warm island is present to the north along the coast, between Aviator and Mariner ice tongues, for most of the year. From February to March a rapid drop in temperature is observed at all stations. A strong thermal gradient develops during February, March, April and October, November, December, between the coastal region and inner highlands. The baric configuration follows the elevation of the area. Annual average pressure and temperature as functions of stations altitude show linear trends. Severe katabatic wind episodes are recorded at all stations, with wind speed exceeding 25 m s–1 and direction following the orographic features of the inner areas. Co-occurrences of these episodes were observed for stations located along stream lines of cold air drainage. The autocorrelation function of maximum wind speed time series shows wind persistence of 2–3 days and wind periodicity of about one week.


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