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Melanie R Taylor - One of the best experts on this subject based on the ideXlab platform.
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Duty or safety? Exploring emergency service personnel's perceptions of risk and decision-making when driving through floodwater
Progress in Disaster Science, 2020Co-Authors: Mozumdar Arifa Ahmed, Katharine Haynes, Matalena Tofa, Gemma Hope, Melanie R TaylorAbstract:Abstract Vehicle-related flood fatalities and rescues due to driving through floodwater are a significant emergency management issue for emergency services. To reduce fatalities, injuries, and costs associated with this risky driving behaviour it is essential to develop strategies to stop or reduce the incidence of people driving through floodwater. In Australia, people are told not to enter floodwater – on foot or in vehicles – with the phrase ‘If it's flooded, forget it’ widely used in official messaging. As first responders responsible for floods, storms and tsunamis, Australian State Emergency Service (SES) personnel are working in flood conditions regularly and are considered an occupationally ‘at-risk’ group for driving through floodwater. Although SES agencies across states and territories in Australia are independently led, they typically promote policies of not entering floodwater to their personnel. Such policies are important for meeting duty of care obligations to employees, for protection of assets (vehicles and equipment), and for upholding organisational reputation (leading by example). This study was undertaken to explore the behaviour of driving through floodwater by SES personnel. The study explored the characteristics of those who have and have not driven through floodwater, and then used detailed situations in which SES personnel entered floodwater in vehicles to analyse their perception of risks, the conditions and contexts in which they entered floodwater, and to identify what influenced their decision to enter. Following an earlier systematic literature review, a detailed online questionnaire was developed and administered to SES personnel from a single agency. Data from 670 respondents indicated that 54.8% had driven through floodwater in the previous two years, and a number of differences in the profile of those who had/had not driven through floodwater were identified. Those more likely to have driven through floodwater included males, volunteer personnel with longer lengths of service, those doing more driving hours per week, those deployed to work in flood conditions, and those with current flood rescue qualifications. The location type, water depth, and water velocity were conditions that contributed more to perception of risk at the time personnel drove through the floodwater. Detailed information about an experience of entering floodwater was obtained from 201 respondents who had driven through floodwater in SES vehicles, and six factors relating to the decision to drive through floodwater were extracted. ‘Organisational training and safety’, ‘External locus of control’ and ‘Absence of risk signals’ were identified as having the greatest influence on risk perception leading to decisions to drive through floodwater. The findings of the study have a number of practical implications for the improvement of occupational safety management; such as upgrading risk assessments strategies, reviewing workplace health and safety policies, enhancing training, increasing skills and knowledge of emergency services personnel about floodwater hazard situations, and improving internal flood risk communication.
Frederick S. Davies - One of the best experts on this subject based on the ideXlab platform.
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Floodwater Oxygen Content, Ethylene Production and Lenticel Hypertrophy in Flooded Mango (Mangifera indica L.) Trees
Journal of Experimental Botany, 1993Co-Authors: Kirk D. Larson, Bruce Schaffer, Frederick S. DaviesAbstract:A system was developed to test the effects of floodwater 02 concentration on ethylene evolution and stem lenticel hypertrophy, and the effects of exogenous ethylene on stem lenticel hypertrophy in mango (Mangifera indica L.) trees. Dissolved 02 concentrations of 1-7 x 10~9 m3 m~3 generally resulted in hypertrophy of stem lenticels within about 6 d of flooding, whereas floodwater 02 concentrations of 13-15 x 10 9 m3 m 3 delayed hypertrophy until about day 9. After 14 d of flooding, there were more than twice the number of hypertrophied lenticels per tree with floodwater 02 concentrations of 1-7 x 10"9 m3 m~3 than with floodwater 02 concentrations of 15 x 10 9 m3 m~3. Ethylene evolution from stem tissue immediately above the floodline increased 4- to 8-fold in trees exposed to floodwater 02 concentrations of 1-2 x 10~9 m3 in 3. increased 2-fold for trees exposed to floodwater 02 concentrations of 6-7 x 10~9 m3 m~3, but remained constant with floodwater 02 concentrations of 13-15 x 10~9 m3 m~3. Plants maintained in highly oxygenated floodwater (13-15 x 10"9 m3 m~3), and given exogenous ethylene developed many hypertrophied lenticels, whereas plants in highly oxygenated water and not given ethylene developed fewer or no hypertrophied lenticels. These data suggest that ethylene plays a role in promotion of stem lenticel hypertrophy in flooded mango trees, and that floodwater dissolved oxygen concentration can regulate stem lenticel hypertrophy and ethylene evolution in this species.
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FLOODWATER OXYGEN CONTENT, ETHYLENE PRODUCTION AND LENTICEL HYPERTROPHY IN FLOODED MANGO TREES
HortScience, 1992Co-Authors: Kirk D. Larson, Bruce Schaffer, Frederick S. DaviesAbstract:The influence of floodwater dissolved O2 content on stem lenticel hypertrophy and endogenous ethylene evolution from mango trees, and the influence of exogenous ethylene on mango stem lenticel hypertrophy was examined. In general, floodwater O2 contents of 1-7 ppm resulted in lenticel hypertrophy within about 6 days of flooding, whereas floodwater O2 contents of 15 ppm delayed hypertrophy until about day 9. After 14 days of flooding, there were more than twice the number of hypertrophied lenticels per tree with floodwater O2 contents of 1-7 ppm than with O2 contents of 15 ppm. Ethylene evolution from aerobic stem tissue increased 4- to 8-fold in trees exposed to floodwater with 1-2 ppm O2, increased 2-fold for trees exposed to 6-7 ppm O2, but remained constant with 15 ppm floodwater dissolved O2 content. During a 10-day flooding period, trees in floodwater with 15 ppm dissolved O2 content, and given exogenous ethylene, developed extensive stem lenticel hypertrophy, whereas no hypertrophy developed on stems of trees receiving no exogenous ethylene and maintained in floodwater with 15 ppm O2. These data suggest that ethylene plays a role in promoting stem lenticel hypertrophy in flooded mango trees.
Mozumdar Arifa Ahmed - One of the best experts on this subject based on the ideXlab platform.
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Duty or safety? Exploring emergency service personnel's perceptions of risk and decision-making when driving through floodwater
Progress in Disaster Science, 2020Co-Authors: Mozumdar Arifa Ahmed, Katharine Haynes, Matalena Tofa, Gemma Hope, Melanie R TaylorAbstract:Abstract Vehicle-related flood fatalities and rescues due to driving through floodwater are a significant emergency management issue for emergency services. To reduce fatalities, injuries, and costs associated with this risky driving behaviour it is essential to develop strategies to stop or reduce the incidence of people driving through floodwater. In Australia, people are told not to enter floodwater – on foot or in vehicles – with the phrase ‘If it's flooded, forget it’ widely used in official messaging. As first responders responsible for floods, storms and tsunamis, Australian State Emergency Service (SES) personnel are working in flood conditions regularly and are considered an occupationally ‘at-risk’ group for driving through floodwater. Although SES agencies across states and territories in Australia are independently led, they typically promote policies of not entering floodwater to their personnel. Such policies are important for meeting duty of care obligations to employees, for protection of assets (vehicles and equipment), and for upholding organisational reputation (leading by example). This study was undertaken to explore the behaviour of driving through floodwater by SES personnel. The study explored the characteristics of those who have and have not driven through floodwater, and then used detailed situations in which SES personnel entered floodwater in vehicles to analyse their perception of risks, the conditions and contexts in which they entered floodwater, and to identify what influenced their decision to enter. Following an earlier systematic literature review, a detailed online questionnaire was developed and administered to SES personnel from a single agency. Data from 670 respondents indicated that 54.8% had driven through floodwater in the previous two years, and a number of differences in the profile of those who had/had not driven through floodwater were identified. Those more likely to have driven through floodwater included males, volunteer personnel with longer lengths of service, those doing more driving hours per week, those deployed to work in flood conditions, and those with current flood rescue qualifications. The location type, water depth, and water velocity were conditions that contributed more to perception of risk at the time personnel drove through the floodwater. Detailed information about an experience of entering floodwater was obtained from 201 respondents who had driven through floodwater in SES vehicles, and six factors relating to the decision to drive through floodwater were extracted. ‘Organisational training and safety’, ‘External locus of control’ and ‘Absence of risk signals’ were identified as having the greatest influence on risk perception leading to decisions to drive through floodwater. The findings of the study have a number of practical implications for the improvement of occupational safety management; such as upgrading risk assessments strategies, reviewing workplace health and safety policies, enhancing training, increasing skills and knowledge of emergency services personnel about floodwater hazard situations, and improving internal flood risk communication.
D\u27sa Eurico - One of the best experts on this subject based on the ideXlab platform.
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Floodwater impact on Galveston Bay phytoplankton taxonomy, pigment composition and photo-physiological state following Hurricane Harvey from field and ocean color (Sentinel-3A OLCI) observations
LSU Digital Commons, 2019Co-Authors: D\u27sa EuricoAbstract:Phytoplankton taxonomy, pigment composition and photo-physiological state were studied in Galveston Bay (GB), Texas (USA), following the extreme flooding associated with Hurricane Harvey (25-29 August 2017) using field and satellite ocean color observations. The percentage of chlorophyll a (Chl a) in different phytoplankton groups was determined from a semi-analytical IOP (inherent optical property) inversion algorithm. The IOP inversion algorithm revealed the dominance of freshwater species (diatom, cyanobacteria and green algae) in the bay following the hurricane passage (29 September 2017) under low salinity conditions associated with the discharge of Floodwaters into GB. Two months after the hurricane (29-30 October 2017), under more seasonal salinity conditions, the phytoplankton community transitioned to an increase in small-sized groups such as haptophytes and prochlorophytes. Sentinel-3A Ocean and Land Colour Instrument (OLCI)-derived Chl a obtained using a red / NIR (near-infrared) band ratio algorithm for the turbid estuarine waters was highly correlated (R-2 \u3e 0.90) to the (high-performance liquid chromatography) HPLC-derived Chl a. Long-term observations of OLCI-derived Chl a (August 2016-December 2017) in GB revealed that hurricane-induced Chl a declined to background mean state in late October 2017. A non-negative least squares (NNLS) inversion model was then applied to OLCI-derived Chl a maps of GB to investigate spatiotemporal variations of phytoplankton diagnostic pigments pre- and post-hurricane; results appeared consistent with extracted phytoplankton taxonomic composition derived from the IOP inversion algorithm and microplankton pictures obtained from an Imaging FlowCytobot (IFCB). OLCI-derived diagnostic pigment distributions also exhibited good agreement with HPLC measurements during both surveys, with R-2 ranging from 0.40 for diatoxanthin to 0.96 for Chl a. Environmental factors (e.g., Floodwaters) combined with phytoplankton taxonomy also strongly modulated phytoplankton physiology in the bay as indicated by measurements of photosynthetic parameters with a fluorescence induction and relaxation (FIRe) system. Phytoplankton in well-mixed waters (mid-bay area) exhibited maximum PSII photochemical efficiency (F-v/F-m) and a low effective absorption cross section (sigma(PSII)), while the areas adjacent to the shelf (likely nutrient-limited) showed low F-v/F-m and elevated sigma(PSII) values. Overall, the approach using field and ocean color data combined with inversion models allowed, for the first time, an assessment of phytoplankton response to a large hurricane-related floodwater perturbation in a turbid estuarine environment based on its taxonomy, pigment composition and physiological state
I. D. Joshi - One of the best experts on this subject based on the ideXlab platform.
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Floodwater impact on Galveston Bay phytoplankton taxonomy, pigment composition and photo-physiological state following Hurricane Harvey from field and ocean color (Sentinel-3A OLCI) observations
Copernicus Publications, 2019Co-Authors: B. Liu, I. D. JoshiAbstract:Phytoplankton taxonomy, pigment composition and photo-physiological state were studied in Galveston Bay (GB), Texas (USA), following the extreme flooding associated with Hurricane Harvey (25–29 August 2017) using field and satellite ocean color observations. The percentage of chlorophyll a (Chl a) in different phytoplankton groups was determined from a semi-analytical IOP (inherent optical property) inversion algorithm. The IOP inversion algorithm revealed the dominance of freshwater species (diatom, cyanobacteria and green algae) in the bay following the hurricane passage (29 September 2017) under low salinity conditions associated with the discharge of Floodwaters into GB. Two months after the hurricane (29–30 October 2017), under more seasonal salinity conditions, the phytoplankton community transitioned to an increase in small-sized groups such as haptophytes and prochlorophytes. Sentinel-3A Ocean and Land Colour Instrument (OLCI)-derived Chl a obtained using a red ∕ NIR (near-infrared) band ratio algorithm for the turbid estuarine waters was highly correlated (R2>0.90) to the (high-performance liquid chromatography) HPLC-derived Chl a. Long-term observations of OLCI-derived Chl a (August 2016–December 2017) in GB revealed that hurricane-induced Chl a declined to background mean state in late October 2017. A non-negative least squares (NNLS) inversion model was then applied to OLCI-derived Chl a maps of GB to investigate spatiotemporal variations of phytoplankton diagnostic pigments pre- and post-hurricane; results appeared consistent with extracted phytoplankton taxonomic composition derived from the IOP inversion algorithm and microplankton pictures obtained from an Imaging FlowCytobot (IFCB). OLCI-derived diagnostic pigment distributions also exhibited good agreement with HPLC measurements during both surveys, with R2 ranging from 0.40 for diatoxanthin to 0.96 for Chl a. Environmental factors (e.g., Floodwaters) combined with phytoplankton taxonomy also strongly modulated phytoplankton physiology in the bay as indicated by measurements of photosynthetic parameters with a fluorescence induction and relaxation (FIRe) system. Phytoplankton in well-mixed waters (mid-bay area) exhibited maximum PSII photochemical efficiency (Fv∕Fm) and a low effective absorption cross section (σPSII), while the areas adjacent to the shelf (likely nutrient-limited) showed low Fv∕Fm and elevated σPSII values. Overall, the approach using field and ocean color data combined with inversion models allowed, for the first time, an assessment of phytoplankton response to a large hurricane-related floodwater perturbation in a turbid estuarine environment based on its taxonomy, pigment composition and physiological state.