Drilling Vessels’ Hurricane Evasion in the Gulf of Mexico

2012 ◽  
Author(s):  
Momen A. Wishahy ◽  
Bob A. Weinzapfel ◽  
Dante C. Diaz ◽  
Devin J. Eyre
Keyword(s):  
Gulf Of Mexico ◽  
Weather Conditions ◽  
Hurricane Evacuation ◽  
Escape Route ◽  
Factors Affecting ◽  
Hurricane Season ◽  
Tactical Decision ◽  
Hurricane Track ◽  
Drilling Site ◽  
Evacuation Plan

A study was carried out to determine the probability of avoiding severe weather conditions generated by historical hurricanes to improve the management of dynamically-positioned (DP) drilling vessels operating in the Gulf of Mexico during hurricane season. Rather than staying on location during an approaching hurricane, DP drilling vessels secure well operations, pull riser, and evade the hurricane. The study considers several factors affecting the measure of success including inherent errors in forecasting hurricane strength, track and speed of advance; types and speeds of vessels; vessel sensitivity to wind and wave conditions; evasion time and direction of evasion; location of the drilling site relative to the hurricane track; and escape route water depth limitations. The results provide a statistical basis for the required evasion time and would be part of the Hurricane Evacuation Plan that stakeholders agree upon to achieve acceptable risk. The simulations could also be used in a training program for captains and considered in the tactical decision-making process regarding when to leave the site and in which direction to go.

Post-fire ephemerals and spinifex-fuelled fires: a decision model for bilby habitat management in the Tanami Desert, Australia

2007 ◽  
Vol 16 (6) ◽  
pp. 741 ◽  
Author(s):  
Richard Southgate ◽  
Susan Carthew
Keyword(s):  
Habitat Suitability ◽  
Decision Model ◽  
Habitat Management ◽  
Fire History ◽  
Spatial Databases ◽  
Ground Cover ◽  
Weather Conditions ◽  
Early Summer ◽  
Annual Rainfall ◽  
Factors Affecting

Seed from post-fire ephemeral plants like Yakirra australiense can form an important component of the diet of the bilby, a threatened arid-dwelling bandicoot. An investigation was conducted to determine the factors affecting the production of Yakirra and fire reoccurrence in the Tanami Desert. A simple decision model was produced to assist managers decide where and when to burn and what to expect regarding Yakirra australiense growth following fire and rainfall. The information used in the model may be derived from existing spatial databases that document rainfall and fire history and could be used to map broad-scale temporal change in total vegetation cover and components of habitat suitability for the bilby. The season and magnitude of rainfall and time-since-fire were the most important variables in the production of Yakirra seed. Rainfall >300 mm within a 2-month period of intense-complete burns could result in >5% Yakirra cover, and >100 mm was required for >1% cover. Negligible Yakirra cover occurred in adjacent long-unburnt plots. Total ground cover and spinifex cover varied substantially in relation to mean annual rainfall, but not in relation to substrate type. Long-unburnt spinifex cover was mostly too sparse to carry a fire in the southern part of the Tanami and the growth of non-spinifex vegetation would be necessary to boost fuel loads sufficiently to carry a fire. Generally, more than 41% cover was required to carry a fire but this was also dependent on weather conditions. Managers should aim to burn in late spring or early summer to improve Yakirra production. Fire management to enhance habitat suitability for the bilby would be of most benefit in the northern part of the Tanami Desert where growth rate of vegetation is greater and there is little existing fire age heterogeneity.

scholarly journals Statistical Analysis of Nutrient Loads from the Mississippi-Atchafalaya River Basin (MARB) to the Gulf of Mexico

Environments ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 8
Author(s):  
Phyllis Okwan ◽  
Yi Zhen ◽  
Huan Feng ◽  
Shinjae Yoo ◽  
Murty S. Kambhampati ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Hurricane Katrina ◽  
River Basin ◽  
Weather Conditions ◽  
Steady Increase ◽  
Moderate Increase ◽  
Nutrient Loads ◽  
Atchafalaya River ◽  
Significant Difference ◽  
Atchafalaya River Basin

This study investigated the annual and seasonal variations in nutrient loads (NO2− + NO3− and orthophosphate) delivered to the Gulf of Mexico from the Mississippi-Atchafalaya River Basin (MARB) and examined the water quality variations. The results indicate that (1) annually, the mean NO2− + NO3− and orthophosphate loads showed a steady increase during 1996–1999, a persistent level during 2000–2007, and a moderate increase during 2008–2016; (2) seasonally, NO2− + NO3− and orthophosphate in MARB in spring and summer were higher than those in autumn and winter. Analysis of variance (ANOVA) identified highly significant differences among seasonal loads; and (3) the median value of NO2− + NO3− in normal weather conditions were higher than that during and right after the hurricanes, while the median value of orthophosphate loads in normal weather conditions was higher than that during the hurricanes, but higher than that right after hurricanes. The two-sample t-test indicates a significant difference (p < 0.046) in orthophosphate loads before and after Hurricane Katrina. Moreover, it is found that there is a significant (p < 0.01) increase in nutrient loads during normal weather conditions. The results indicate that hurricane seasons can significantly influence the nutrient loads from the MARB to the Gulf of Mexico.

scholarly journals Construction of ropeways in Slovakia in terms of pre-construction design using helicopters (case study)

2019 ◽  
Vol 263 ◽  
pp. 01002
Author(s):  
Andrej Bisták ◽  
Zdenka Hulínová
Keyword(s):  
Construction Industry ◽  
Transport Mechanism ◽  
Simulation Models ◽  
Weather Conditions ◽  
Positive Experience ◽  
Site Location ◽  
Factors Affecting ◽  
Construction Design ◽  
History Of

Ropeways usually provide access to locations inaccessible to other means of transport. Due to this fact, the construction of ropeways is extraordinarily taxing in terms of both, technology and logistics. The site location is often in terrain difficult to access, which often precludes deployment of common construction mechanisms in ropeway construction. In such case, it is advisable to deploy a transport mechanism independent of the terrain – a helicopter. Functioning as “flying cranes“, the helicopters have been used in construction industry in Slovakia for six decades now. Having amassed positive experience, even the “conventional“ construction industry of the time, especially its ropeway transport segment, started to use the benefits of helicopters, with helicopter deployment subsequently gaining ground and becoming the mainstream technological procedure. Ropeway construction can hardly be feasible without them even nowadays. Throughout the history of helicopter deployment in construction industry, a constant search of improving the efficiency of their work has been under way, necessitated by the helicopter’s sensitivitiy to weather conditions and work procedures alike. The paper presents an analysis of the factors affecting helicopter operation together with a proposed methodology of modeling their work in simulation models and the benefits of such approach.

Mainland China nurses’ willingness to report to work in a disaster

2013 ◽  
Vol 8 (4) ◽  
pp. 273-282 ◽  
Author(s):  
Alice Yuen Loke, PhD, MN, BSN, RN ◽  
Wai Man Olivia Fung, DHSc, MPH, BN, RN ◽  
Xiwen Liu, MSc, RN
Keyword(s):  
Infectious Disease ◽  
Family Members ◽  
Mainland China ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Convenience Sample ◽  
Factors Affecting ◽  
Evacuation Plan ◽  
Disaster Training ◽  
Willingness To Report

A cross-sectional study among a convenience sample of nurses in China was conducted to understand the factors affecting Chinese nurses’ willingness to report to work in a disaster. A total of 946 questionnaires were collected. Nearly 90 percent of nurses regarded disaster self-help information, an evacuation plan, and contingency measures a must in preparing for disaster care. Many nurses indicated willingness to work during a disaster that may threaten the safety of their family members than when there is a life-threatening infectious disease outbreak (83.6 and 69.6 percent, p = 0.000). Nurses with longer years of clinical experience were more willing to work in both situations (p = 0.014 and 0.000). Fear of contracting an infectious disease and spreading it to family members was a major factor for nurses’ unwillingness to report to work. Hospital administrators should understand their workforce’s willingness in reporting to work and provide appropriate disaster training and support to maximize workforce in a disaster.

CO2 fluxes and carbon balance of an agricultural grassland in southern Finland

2020 ◽  
Author(s):  
Laura Heimsch ◽  
Annalea Lohila ◽  
Liisa Kulmala ◽  
Juha-Pekka Tuovinen ◽  
Mika Korkiakoski ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Balance ◽  
Management Practices ◽  
Agricultural Soils ◽  
Weather Conditions ◽  
Factors Affecting ◽  
Management Procedures ◽  
Mitigate Climate Change

&lt;p&gt;Agriculture is globally a significant source of carbon emissions to the atmosphere. Main causes for these high emissions are conventional intensive management practices which include such as frequent ploughing, monocropping and high use of agrochemicals. These practices contribute to the loss of biodiversity and soil organic matter, as well as to the CO&lt;sub&gt;2&lt;/sub&gt; emissions from land use. Recently, it has been recognised that agriculture functioning on the basis of regenerative practices is one of the most potential tools to mitigate climate change.&lt;/p&gt;&lt;p&gt;It is well known that topsoil layer and especially humus-rich soils can store more carbon than atmosphere and vegetation together. Therefore, increasing the amount of soil organic matter in the agroecosystems, by applying enhanced management practices such as reduced tillage, high biodiversity and cover cropping, agricultural soils would not only help to mitigate climate change but also to restore soil quality and fertility. To understand the carbon dynamics on different agricultural sites, factors affecting and comprising the carbon balance, and to verify soil carbon and ecosystem models, continuous long-term monitoring of the GHG fluxes is essential at such managed ecosystems. Here we present results from a new eddy covariance (EC) flux study site located in southern Finland.&lt;/p&gt;&lt;p&gt;Continuous CO&lt;sub&gt;2&lt;/sub&gt; flux measurements using the EC method have been conducted at Qvidja farm on mineral (clay) soil forage grassland in Parainen, southern Finland (60.29550&amp;#176;N, 22.39281&amp;#176;E) since the spring 2018. Based on the flux and biomass data, the annual carbon balance was estimated to be negative, i.e. the site acted as an overall sink of carbon even in the dry and hot year 2018. However, the seasonal CO&lt;sub&gt;2&lt;/sub&gt; fluxes were greatly dependent on weather conditions and management procedures. Results from 2019 show that the growing season accompanied with more mature and dense grass, a bit higher precipitation and lower temperatures, as well as higher cutting height was more favorable for carbon uptake in Qvidja as compared to year 2018.&lt;/p&gt;

scholarly journals Factors affecting migratory bird routes over the Gulf of Mexico

1994 ◽  
Vol 4 (2-3) ◽  
pp. 251-262 ◽  
Author(s):  
John H. Rappole ◽  
Mario A. Ramos
Keyword(s):  
Gulf Of Mexico ◽  
Central America ◽  
Gulf Coast ◽  
Bird Species ◽  
Migratory Bird ◽  
Factors Affecting ◽  
Migratory Flight ◽  
Prevailing Wind Direction ◽  
Northern Gulf Coast ◽  
The Tropics

SummaryOver half of the 332 migratory bird species that breed in North America and winter in the tropics are affected by the obstacle to migratory flight presented by the Gulf of Mexico. Landbird migration in the vicinity of the Gulf is considered from an historical perspective, and in light of netting and observational data from the western Gulf coast. A trans-Gulf crossing from the northern Gulf coast to, or over, Yucatan is the most commonly followed fall route for eastern Nearctic migrants that winter in Central America. The spring route for these species is different, involving a more westerly trans–Gulf course for some individuals, and a circum–Gulf route for others. Prevailing wind direction and the probability of meeting turbulence over the Gulf are suggested as the main selective factors affecting route form for Gulf–area migrants.

scholarly journals A Model to Estimate the Amount of Primary Inoculum of Elsinoë ampelina

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1167-1171 ◽  
Author(s):  
Odile Carisse ◽  
Annie Lefebvre
Keyword(s):  
Temporal Dynamics ◽  
Leaf Growth ◽  
Weather Conditions ◽  
Base Temperature ◽  
Eastern Canada ◽  
Management Tools ◽  
Factors Affecting ◽  
Primary Inoculum ◽  
Elsinoe Ampelina ◽  
Serious Disease

In Eastern Canada, anthracnose, caused by the fungus Elsinoë ampelina, is a serious disease on susceptible grape cultivars. In the absence of management tools, anthracnose management relies almost exclusively on fungicide applications programmed at fixed intervals. Therefore, a better understanding of the factors affecting primary inoculum release and abundance would help in the timing of the first fungicide applications. The temporal dynamics of airborne primary inoculum released from cane cankers were investigated from 2007 to 2010. One to three times per week, starting in the first week of April, six 12-cmlong cane pieces were randomly selected from diseased canes that had overwintered on a vineyard floor. The concentration of E. ampelina conidia was expressed as the number of conidia per square millimeter of canker. In total, 27, 32, 33, and 118 samplings were conducted in 2007, 2008, 2009, and 2010, respectively, with the 118 samplings conducted on three sites at 49, 35, and 34 samplings for site 1, 2, and 3, respectively. Each year, the number of conidia per square millimeter of canker was expressed as the proportion of seasonal inoculum (PSI) at the same site and analyzed as a function of degree-days (DD; base temperature = 0°C) accumulated since 1 April (cumulative degreedays [CDD]). The nonlinear sigmoid model in the form PSI = 1.003/(1 + e–((CDD – 566.133)/139.204)) provided adequate fit to the observed data (P < 0.0001, R2 = 0.97). When the model was validated against independent data, the model adequately predicted PSI; however, reliability was improved by adding a “dry days” threshold of 6 days during which accumulation of DD is stopped. This study shows that primary inoculum of grape anthracnose is available early in the season before bud break; meaning that emerging leaves could be infected provided that weather conditions are favorable. The results also show that there is an overlap in the availability of primary and secondary inoculum, mainly during the period of rapid leaf growth, a situation that may explain the explosive nature of the disease. The results suggest that, on susceptible cultivars and when there is a history of anthracnose in the vineyard, a fungicide spray program should be initiated early in the season, as soon as leaves are present.

scholarly journals Seasonality of strandings and bycatch of harbour porpoises in the Sea of Azov: the effects of fisheries, weather conditions, and life history

2014 ◽  
Vol 72 (3) ◽  
pp. 981-991 ◽  
Author(s):  
Karina Vishnyakova ◽  
Pavel Gol'din
Keyword(s):  
Life History ◽  
Foraging Behaviour ◽  
Weather Conditions ◽  
Nutritional Stress ◽  
Sea Of Azov ◽  
Factors Affecting ◽  
The Sea Of Azov ◽  
Conservation Measure ◽  
Calving Season ◽  
Typical Summer

Abstract In this study, we analyse seasonal aspects of harbour porpoise strandings in the Sea of Azov and discuss factors affecting the stranding rate. Data on 633 strandings were obtained from monitoring of a 35-km long area of the south coast of the Sea of Azov in 1999–2013. A distinct peak of strandings fell in July and August: it depended on the bycatch peak and calving season. Stranding rates depended neither on weather conditions nor on the seasonal fishing activities (including IUU fisheries). Moreover, stranding peaks in the neighbouring Black Sea were also tied to the calving season rather than to the fishing activities. We suggest that the seasonal mortality patterns are indirectly determined by nutritional stress: in Atlantic, winter-stranding oceanic populations and summer-stranding inner-sea populations occur that also possibly differ in the seasonal dynamics of body mass, weaning time or duration of mother–calf association, and dentine structure. In a typical summer-stranding population, summer is the season of nutritional stress, parturition, independent foraging of yearlings and lactation of nursing females, which leads to the risky foraging behaviour near gillnets. Another possible factor of increased bycatch is the seasonal habitat preference, corresponding to the gillnet preferences. Therefore, stranding and bycatch seasonality of porpoises can largely be explained by the aspects of their life history and foraging behaviour rather than by weather conditions and fisheries. This supports the time–area closure strategy as an adequate conservation measure, which would consider minimizing the conflict of interest with fisheries.

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