Study on Short-time Flight Timing Optimization of Airport Group Based on Weather Conditions

Proper determinations of light use efficiency (LUE) and absorbed photosynthetically active radiation (APAR) are essential for LUE models to simulate gross primary productivity (GPP). This study intended to apply the photochemical reflectance index (PRI) to track LUE or APAR variations in a subtropical coniferous forest using tower-based PRI and GPP measurements. To improve the ability of using PRI to track LUE or APAR, a two-leaf approach differentiating sunlit and shaded leaves was used to process the remote sensing and flux data. However, penumbra region, the ‘grey region’ between sunlit and shaded leaves, increases the difficulty for quantifying the fractions of sunlit and shaded leaves. Firstly, three methods with different ways on treating the penumbra region were investigated for estimating the fraction of sunlit leaves (PT). After evaluating the correlations between observed PRI (PRIobs) and inversely retrieved PRI (PRIinv) from estimated PT using the three methods, we found that treating a substantial portion of penumbra region as sunlit leaves was reasonable and using the ratio of canopy reflectance to leaf reflectance as PT was accurate and efficient. Based on this, we used the two-leaf approach to estimate the canopy-level PRI, aiming to evaluate the ability of using PRI as a proxy for LUE or APAR. Results showed that PRI was able to capture half-hourly and daily changes in LUE and APAR, and the two-leaf approach could enhance the correlations between PRI and both LUE and APAR at both half-hourly and daily time steps. Strong diurnal correlations (averaged R = 0.82 from 173 days) between two-leaf PRI and APAR were found on more than 80% days and the relationship between them over the whole study period was also very significant (R2>0.5, p<0.0001) regardless of different climate conditions, suggesting that the two-leaf PRI was probably a better proxy for APAR than for LUE at short-term scale as PRI mainly represented the absorbed energy allocated to photoprotection at short time scale and was a direct outcome driven by APAR. However, the scattered relationships of PRI with LUE and APAR indicated there were still many limitations in usage of PRI to accurately estimate physiological parameters affected by changing weather conditions, pigment pool size, etc., which needed further exploration.

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Flight Activity and Displacement in the Rutherglen Bug Nysius Vinitor (Hemiptera: Lygaeidae).

Australian Journal of Zoology ◽

10.1071/zo9730413 ◽

1973 ◽

Vol 21 (3) ◽

pp. 413 ◽

Cited By ~ 11

Author(s):

M Kehat ◽

M Wyndham

Keyword(s):

Host Plants ◽

Population Studies ◽

Weather Conditions ◽

Flight Activity ◽

Migratory Behavior ◽

Seasonal Fluctuations ◽

Large Numbers ◽

Seasonal Migrations ◽

Population Source ◽

Short Time

Population studies for determining seasonal fluctuations of N. vinitor indicated that the appearance or disappearance of populations within a short time can be attributed mainly to its highly migratory behavior. N. vinitor always migrated when host plants dried up, and sometimes also when they were still green. Continuous quantitative records of flight activity, made near the population source, showed that the seasonal migrations of N. vintor closely reflected its population curve. As populations increased and declined throughout the season, migrants were produced continuously, resulting in a fairly smooth succession of departing individuals which became particularly obvious when large numbers suddenly discharged which occurred when special weather conditions caused sudden excessive flights.

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Experimental Analysis of a Solar Desalination Prototype

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.592-594.2350 ◽

2014 ◽

Vol 592-594 ◽

pp. 2350-2354

Author(s):

Ajeet Pratap Singh ◽

A. Shaija

Keyword(s):

Experimental Investigation ◽

Weather Conditions ◽

Maximum Temperature ◽

Small Power ◽

Solar Desalination ◽

Typical Day ◽

Institute Of Technology ◽

Parabolic Reflectors ◽

Flat Plate Solar Collector ◽

Short Time

. This paper presents the experimental investigation of a solar desalination prototype using the humidification dehumidification principle at the weather conditions of Calicut City. The prototype is designed and fabricated at the National Institute of Technology, Calicut to conduct the experimental investigation of the dynamic behaviour of the solar desalination unit during summer season (November, December & January) and during a typical day in December was carried out to study the temporal evolutions of the temperature of air and water and the relative humidity at the inlet and the outlet of each component of the system. The results showed excellent behavior of series of parabolic reflectors over flat plate solar collector and enhanced productivity, thermally efficient and simultaneously reaches a maximum temperature of more than 75°C in a short time. The running cost of the system is low as it consumes very small power to run a small air blower and a water pump reducing the final cost per liter of fresh water.

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GEODETIC MONITORING DURING THE OPERATION THE FOOTBALL STADIUMS OF THE WORLD CHAMPIONSHIP 2018

Vestnik SSUGT (Siberian State University of Geosystems and Technologies) ◽

10.33764/2411-1759-2020-25-3-42-52 ◽

2020 ◽

Vol 25 (3) ◽

pp. 42-52

Author(s):

Nikolay V. Kanashin ◽

◽

Dmitry A. Afonin ◽

Keyword(s):

Weather Conditions ◽

Time Frame ◽

High Accuracy ◽

Monitoring Methods ◽

Adverse Conditions ◽

Adverse Weather Conditions ◽

Adverse Weather ◽

The World ◽

Short Time ◽

Football Stadiums

The technologies of geodetic works in monitoring of various structures can still be associated with a number of difficulties caused by the influence of different factors despite the studies of many authors on that theme. The article describes the high accuracy geodetic monitoring of the football stadiums "Rostov Arena" and "Kaliningrad" that took place in a short time frame and in adverse weather conditions. The article gives two geodetic monitoring methods such as creating serving network by side-points method and electronic block tacheometry. The technology and the adjustment of measurements made during monitoring are described in the article. The results show that the use of the side-points method and electronic block tacheometry ensures high accuracy measurements even in adverse conditions for observations. Practical conclusions and recommendations are set out. The article may be useful for specialists in the field of monitoring and geodetic control of deformations of structures.

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Estimating Extreme Response of Drag Dominated Offshore Structures From Simulated Time Series of Structural Response

Volume 2: Structures, Safety and Reliability; Petroleum Technology Symposium ◽

10.1115/omae2007-29119 ◽

2007 ◽

Cited By ~ 2

Author(s):

A. Naess ◽

O. Gaidai ◽

S. Haver

Keyword(s):

Response Time ◽

Structural Response ◽

Weather Conditions ◽

Response Prediction ◽

Offshore Structures ◽

Rate Function ◽

Extreme Response ◽

Time Histories ◽

Short Time

The paper presents a study of extreme response statistics of drag dominated offshore structures, showing a pronounced dynamic behaviour when subjected to harsh weather conditions. The key quantity for extreme response prediction is the mean up-crossing rate function, which can be simply extracted from simulated stationary response time histories. Present practise for obtaining adequate extremes for design purposes requires a number — say 20 or more — of 3-hour time domain analyses for several extreme sea states. For early phase considerations, it would be convenient if extremes of a reasonable accuracy could be obtained based on shorter and fewer simulations. It is therefore of interest to develop specific methods which make it possible to extract the necessary information from relatively short time histories. The method proposed in this paper opens up the possibility to predict simply and efficiently long-term extreme response statistics, which is an important issue for the design of offshore structures. A short description of this is given, but in the present paper the emphasis is on short-term analyses. The results presented are based on extensive simulation results for the Kvitebjo̸rn jacket structure, in operation on the Norwegian Continental Shelf. Specifically, deck response time histories for different sea states simulated from a MDOF model were used as the basis for our analyses.

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Persistent Food Insecurity from Policy Failures in Pakistan

The Pakistan Development Review ◽

10.30541/v47i4iipp.817-834 ◽

2008 ◽

Vol 47 (4II) ◽

pp. 817-834 ◽

Cited By ~ 4

Author(s):

Zakir Hussain ◽

Waqar Akram

Keyword(s):

Food Security ◽

Food Insecurity ◽

Green Revolution ◽

Weather Conditions ◽

Healthy Life ◽

Food Grains ◽

The People ◽

Short Time ◽

Policy Failures

Food security means, “All the people, all the time, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preference for an active and healthy life” [FAO (1996)]. Three types of food insecurity generally exist in any country, which are: transitory food insecurity that is short time food insecurity occurs due to sporadic crises; chronic food insecurity that arises as a result of long term but not easily changed conditions; cyclic food insecurity that arises due to seasonal fluctuations. If cyclic food insecurity existed in any country for at least six months than it was called as chronic cyclic food insecurity and if it persisted less than six months than called as transitory cyclic food insecurity. Pakistan has made a lot of progress since independence in the field of agriculture in terms of production, yields, and growth in area under cultivation. Indus agriculture has experienced a Green Revolution and is striving for yellow and blue revolutions. However, it could have done far better. Though the overall growth of the Pakistan’s economy has largely been dependent upon the performance of agriculture, over the years, not much investment has been made for the development of this sector. Agriculture performance still depends upon, quite a lot, upon the weather conditions every year. The yields of most of crops are far below the levels achieved at the progressive farms (extension gap). From the Figure 1 it is evident that in the last decade (90s) food availability was increasing and then went down and formed the inverted u-shape. After that again fluctuating means there is no surety about food security. It is also comparable with agriculture growth rate. According to latest statistics in Pakistan as many as 50 million people are engaged in agriculture operations and produce only 25 million tons of food grains. As against this in India, 546 million people are engaged in agricultural operations and produce 176 million tons of food grains, in USA only 6 million people engaged in agriculture, produce 347 million of food grains.

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Enfermedades foliares del caucho (Hevea brasiliensis Muell. Arg.) establecido en un campo clonal ubicado en el Magdalena Medio Santandereano (Colombia).

Ciencia y Tecnología Agropecuaria ◽

10.21930/rcta.vol12_num1_art:216 ◽

2010 ◽

Vol 12 (1) ◽

pp. 65 ◽

Cited By ~ 2

Author(s):

Yeirme Yaneth Jaimes S. ◽

Jairo Rojas M.

Keyword(s):

Hevea Brasiliensis ◽

Rubber Tree ◽

Weather Conditions ◽

Climatic Conditions ◽

Infection Process ◽

Time Intervals ◽

Foliar Diseases ◽

Microcyclus Ulei ◽

Foliar Tissue ◽

Short Time

Las enfermedades foliares fúngicas son consideradas las principales causas del declive de la producción del caucho natural en los países productores. Dada su importancia, en el presente estudio se evaluó su incidencia y severidad en los clones FX 3864, IAN 710, PB 217, PB 260, PB 235, PB 314, RRIC 110, RRIM 703, RRIM 600 establecidos en campo clonal en la región del magdalena medio santandereano. En cinco muestreos realizados entre agosto de 2009 y marzo de 2010, se determinó la incidencia y severidad de patógenos foliares en hojas en estado B y D, respectivamente. en el tejido foliar de los clones evaluados se encontró la incidencia de hongos de los géneros Colletotrichum, Fusarium, Dreschlera, Microcyclus ulei y royas. Las enfermedades causadas por los potenciales patógenos se presentaron con mayor severidad en los clones RRIm 703 y FX 3864 en un 51% y 64%, respectivamente. En contraste, las enfermedades se presentaron con menor severidad en los clones IAN 710, PB 314 y RRIC 110 con valores entre el 3% y el 7%. Dentro de los hongos incidentes, se encontraron varios patógenos potenciales del cultivo, requiriéndose profundizar en el conocimiento del ataque e interacciones con el hospedero y las condiciones climáticas de la región. Además, se debe correlacionar su incidencia y severidad con datos de temperatura y humedad en intervalos de tiempo cortos. esto permitirá estimar las condiciones climáticas y los tiempos que favorecen los procesos de infección y desarrollo de las enfermedades foliares en cultivos de caucho de la región. Foliar diseases of the rubber tree (Hevea brasiliensis Muell. Arg.) planted on a clonal garden at the Middle Magdalena region of the Department of Santander (Colombia).Fungal foliar diseases are considered the major cause of yield decline in rubber tree producing countries. Thus, this study assessed incidence and severity in the Clones FX 3864, IAN 710, PB 217, PB 260, PB 235, PB 314, rich man 110, RRIM 703, RRIM 600 established in a clonal garden in the middle magdalena region of the Department of santander (Colombia). Five surveys conducted between August 2009 and march 2010, determined the fungal pathogen incidence and severity on leaves at stage B and D, respectively. Foliar tissue of assessed clones showed incidence of Colletotrichum, Fusarium, Dreschlera, Microcyclus ulei genera and rusts. Diseases caused by these potential pathogens occurred severely in the RRIM 703 and FX 3864 clones with 51% and 64% respectively. In contrast, diseases were less severe in IAN 710, PB 314 and RRIC 110 clones with values between 3% and 7%. Within the results observed, several potential crop fungi pathogens were found, which require a deeper understanding of their attack and interactions with the host and regional climatic conditions. Furthermore, the correlation of incidence and severity with temperature and humidity data at short time intervals should be determined. This will allow the prediction of the weather conditions and periods that bring on the infection process and the development of fungal diseases on rubber crops in the region.

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Change of species set and abundance along a short time gradient: The impact of weather conditions on the conservation of butterflies.

Beiträge zur Entomologie = Contributions to Entomology ◽

10.21248/contrib.entomol.49.2.447-461 ◽

1999 ◽

Vol 49 (2) ◽

pp. 447-461

Author(s):

Stefan Brunzel ◽

Henning Elligsen

Keyword(s):

Nature Conservation ◽

Weather Conditions ◽

Short Time ◽

The Impact

In einer artenarmen Region im Märkischen Sauerland (Nordrhein-Westfalen) wurde 1989-1991 eine rasterfeldbezogene Dauerbeobachtung von Tagfaltern begonnen und 1997 wiederholt. Gegenüber 1989-1991 zeigten sich 1997 Unterschiede im Artenset und der Abundanz einiger Arten. In Übereinstimmung mit anderen Untersuchungen wird diesbezüglich der Einfluß von Witterungsbedingungen diskutiert. In einem Betrachtungszeitraum von 1987 bis 1995 sind die Witterungsbedingungen im Untersuchungsgebiet seit 1989 günstiger geworden. Die mittleren Monatstemperaturen und die monatliche Sonnenscheindauer sind vor allem zwischen 1989 und 1992 deutlich angestiegen, während die monatliche Niederschlagssumme stark abgenommen hat. Dieser Anstieg war sowohl während der hauptsächlichen Falterflugzeit (April bis September) als auch von Oktober bis März (möglicherweise für Präimaginalstadien relevant) festzustellen. - Einige vergleichsweise xerothermophile Arten konnten 1997 erstmals nachgewiesen werden. Andere, während der letzten 30 Jahre verschwundene Arten, wurden wiedergefunden. Mehrere Arten mit individuenarmen Vorkommen während der Erfassungen 1989-1991 besaßen 1997 eine größere Zahl und individuenstärkere Vorkommen, obwohl sich weder die Landschaftsstrukturen noch die Habitatbedingungen im Untersuchungsgebiet wesentlich geändert haben. Witterungsbedingungen werden hierfür als Ursache diskutiert und mit möglichen Auswirkungen von Habitatmanagement verglichen.StichwörterButterfly monitoring, species set, impact of weather conditions, Germany, nature conservation.

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Rapid Detection of Windthrows Using Sentinel-1 C-Band SAR Data

Remote Sensing ◽

10.3390/rs11020115 ◽

2019 ◽

Vol 11 (2) ◽

pp. 115 ◽

Cited By ~ 23

Author(s):

Marius Rüetschi ◽

David Small ◽

Lars Waser

Keyword(s):

Rapid Detection ◽

Temperate Forests ◽

Weather Conditions ◽

Independent Study ◽

Storm Event ◽

Storm Events ◽

Before And After ◽

Sar Data ◽

Short Time ◽

Flexible Application

Storm events are capable of causing windthrow to large forest areas. A rapid detection of the spatial distribution of the windthrown areas is crucial for forest managers to help them direct their limited resources. Since synthetic aperture radar (SAR) data is acquired largely independent of daylight or weather conditions, SAR sensors can produce temporally consistent and reliable data with a high revisit rate. In the present study, a straightforward approach was developed that uses Sentinel-1 (S-1) C-band VV and VH polarisation data for a rapid windthrow detection in mixed temperate forests for two study areas in Switzerland and northern Germany. First, several S-1 acquisitions of approximately 10 before and 30 days after the storm event were radiometrically terrain corrected. Second, based on these S-1 acquisitions, a SAR composite image of before and after the storm was generated. Subsequently, after analysing the differences in backscatter between before and after the storm within windthrown and intact forest areas, a change detection method was developed to suggest potential locations of windthrown areas of a minimum extent of 0.5 ha—as is required by the forest management. The detection is based on two user-defined parameters. While the results from the independent study area in Germany indicated that the method is very promising for detecting areal windthrow with a producer’s accuracy of 0.88, its performance was less satisfactory at detecting scattered windthrown trees. Moreover, the rate of false positives was low, with a user’s accuracy of 0.85 for (combined) areal and scattered windthrown areas. These results underscore that C-band backscatter data have great potential to rapidly detect the locations of windthrow in mixed temperate forests within a short time (approx. two weeks) after a storm event. Furthermore, the two adjustable parameters allow a flexible application of the method tailored to the user’s needs.

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Automatic detection of avalanches and debris flows by seismic methods

Journal of Glaciology ◽

10.3189/002214307783258468 ◽

2007 ◽

Vol 53 (182) ◽

pp. 461-472 ◽

Cited By ~ 33

Author(s):

Bjarni Bessason ◽

Gísli Eiríksson ◽

Óðinn Thorarinsson ◽

Andrés Thórarinsson ◽

Sigurður Einarsson

Keyword(s):

Debris Flows ◽

Automatic System ◽

Traffic Accidents ◽

Automatic Detection ◽

Weather Conditions ◽

The West ◽

Research Project ◽

The Road ◽

Short Time ◽

Seismic Measurements

AbstractThe road along the Óshlíð hillside in the West Fjords region of Iceland is one of the most hazardous roads in Iceland due to avalanches, rockfalls and debris flows. The road has little traffic, but nevertheless traffic accidents caused by the severe conditions at the site are common. A number of avalanche tracks are found on the hillside. In some of these tracks, avalanches occur more frequently than in others. When there is an avalanche threat, avalanches generally flow over many tracks in a short time. Monitoring vibrations in the tracks with the highest avalanche frequency can indicate when avalanches start flowing down the hillside in a snowstorm, and avalanche hazard can then be declared with the specific site indicated. The same methodology can be used for rockfalls and debris flows, which are strongly affected by weather conditions and typically occur in clusters. Based on this knowledge, a research project was initiated in February 1996 with the objective of developing an automatic system based on seismic measurements to detect and analyze avalanches on the Óshlíð hillside and to instantly send a warning to a control station.

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