Kristen Welsh-Unwala, Anne Imig, Isabella Listl, Arno Rein
Freshwater lenses, a layer of fresh water that floats atop saline groundwater, are vulnerable sources of drinking water for small islands. The threats to freshwater lenses, and their recovery following catastrophic events, is not well documented. Due to storm surge and flooding during the Category 5 Hurricane Dorian in September 2019, the freshwater lenses of Grand Bahama were inundated with salt water, removing the freshwater source of drinking water for the island. This study builds on previous work to monitor the recovery of the freshwater lenses three years after the hurricane by assessing tidal lag, as well as stable isotopes in water (δ2H and δ18O), to understand the hydrologic characteristics of the FWL in Grand Bahama. Results from electrical conductivity revealed that the tidal lag, or the time it takes for the tidal effect to be observed in groundwater, was approximately 2.5 hours on average. Through stable isotope analysis of precipitation samples, we determined a local meteoric water line of δ2H = 8.2 * δ18O + 12.2, which is close to the global meteoric water line. Groundwater samples did not show evidence of significant evaporation from precipitation. These results serve as baseline data for additional monitoring and recovery efforts on Grand Bahama.
{"title":"Grand Bahama Post-Hurricane Dorian","authors":"Kristen Welsh-Unwala, Anne Imig, Isabella Listl, Arno Rein","doi":"10.15362/ijbs.v29i1.543","DOIUrl":"https://doi.org/10.15362/ijbs.v29i1.543","url":null,"abstract":"Freshwater lenses, a layer of fresh water that floats atop saline groundwater, are vulnerable sources of drinking water for small islands. The threats to freshwater lenses, and their recovery following catastrophic events, is not well documented. Due to storm surge and flooding during the Category 5 Hurricane Dorian in September 2019, the freshwater lenses of Grand Bahama were inundated with salt water, removing the freshwater source of drinking water for the island. This study builds on previous work to monitor the recovery of the freshwater lenses three years after the hurricane by assessing tidal lag, as well as stable isotopes in water (δ2H and δ18O), to understand the hydrologic characteristics of the FWL in Grand Bahama. Results from electrical conductivity revealed that the tidal lag, or the time it takes for the tidal effect to be observed in groundwater, was approximately 2.5 hours on average. Through stable isotope analysis of precipitation samples, we determined a local meteoric water line of δ2H = 8.2 * δ18O + 12.2, which is close to the global meteoric water line. Groundwater samples did not show evidence of significant evaporation from precipitation. These results serve as baseline data for additional monitoring and recovery efforts on Grand Bahama.","PeriodicalId":484073,"journal":{"name":"International Journal of Bahamian Studies","volume":"26 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134907349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Devin Chambers, Carlton Watson, Okell Dames, George Odhiambo, Williamson Gustave
Food insecurity is a major concern in The Bahamas due to our inadequate food and agricultural infrastructure and heavy reliance on imports. To mitigate this threat, the Bahamian government has been encouraging homeowners to engage in backyard farming. However, the success of backyard farming relies on the presence of healthy soils. In this study, we conducted a comparative analysis of soil health in backyard farms across several islands in The Bahamas. Our analysis focused on key indicators such as nutrient availability, pH, salinity, water-holding capacity, and organic carbon. Our results revealed that none of the 38 soil samples analysed fell within the optimal range for all of the selected indicators. Our results suggested that soil treated with synthetic fertilizer did not exhibit higher nutrient availability compared to naturally fertilized or unfertilized samples. Additionally, through correlation analysis, we found a positive relationship between organic carbon and water-holding capacity. Conversely, negative correlations were observed between pH and nitrogen, as well as organic carbon and pH. These correlations imply that optimizing pH levels and enhancing water holding capacity may play a crucial role in improving soil health in The Bahamas, with particular attention to increasing organic carbon content.
{"title":"Comparative Analysis of Soil Health in Backyard Farms on Multiple Islands of The Bahamas","authors":"Devin Chambers, Carlton Watson, Okell Dames, George Odhiambo, Williamson Gustave","doi":"10.15362/ijbs.v29i1.535","DOIUrl":"https://doi.org/10.15362/ijbs.v29i1.535","url":null,"abstract":"Food insecurity is a major concern in The Bahamas due to our inadequate food and agricultural infrastructure and heavy reliance on imports. To mitigate this threat, the Bahamian government has been encouraging homeowners to engage in backyard farming. However, the success of backyard farming relies on the presence of healthy soils. In this study, we conducted a comparative analysis of soil health in backyard farms across several islands in The Bahamas. Our analysis focused on key indicators such as nutrient availability, pH, salinity, water-holding capacity, and organic carbon. Our results revealed that none of the 38 soil samples analysed fell within the optimal range for all of the selected indicators. Our results suggested that soil treated with synthetic fertilizer did not exhibit higher nutrient availability compared to naturally fertilized or unfertilized samples. Additionally, through correlation analysis, we found a positive relationship between organic carbon and water-holding capacity. Conversely, negative correlations were observed between pH and nitrogen, as well as organic carbon and pH. These correlations imply that optimizing pH levels and enhancing water holding capacity may play a crucial role in improving soil health in The Bahamas, with particular attention to increasing organic carbon content.","PeriodicalId":484073,"journal":{"name":"International Journal of Bahamian Studies","volume":"6 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amin S. Kabir, Nimmi C. Sharma, Edward Knowles, Seth Gagnon, Justin Fagnoni, John E. Barnes
Aerosols, the tiny suspended particles in the atmosphere, are a widely studied topic around the world due to their effects on the Earth’s radiation budget, climate change, and human health. Knowledge of the spatial and temporal distribution of aerosols is essential to assess air pollution and predict potential climate change. This study measured aerosol optical depth (AOD) and altitude-dependent aerosol extinctions in Nassau, The Bahamas simultaneously using a camera-based imaging lidar (CLidar). The bistatic geometry of the setup which consisted of a wide-angle lens fitted to a charge-coupled device (CCD) camera, allowed for the measurement of extinctions at all altitudes at once without requiring expensive timing electronics common to lidars. A case study was conducted on November 5, 2018. The top of the boundary layer beyond which aerosol extinction was nearly zero was detected at ~ three km above sea level. Due to the excellent resolution of the CLidar at lower altitudes, variations of aerosol concentrations within the boundary layer are efficiently detected. Optical depth was measured using the same CLidar camera at the same time, utilising star photometry, and was found to be 0.043 ± 0.040. The value falls within the range of assumed values of AOD near the regions obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite.
{"title":"Study of Atmospheric Aerosols in The Bahamas Using Camera Lidar and Star Photometry Techniques","authors":"Amin S. Kabir, Nimmi C. Sharma, Edward Knowles, Seth Gagnon, Justin Fagnoni, John E. Barnes","doi":"10.15362/ijbs.v29i1.519","DOIUrl":"https://doi.org/10.15362/ijbs.v29i1.519","url":null,"abstract":"Aerosols, the tiny suspended particles in the atmosphere, are a widely studied topic around the world due to their effects on the Earth’s radiation budget, climate change, and human health. Knowledge of the spatial and temporal distribution of aerosols is essential to assess air pollution and predict potential climate change. This study measured aerosol optical depth (AOD) and altitude-dependent aerosol extinctions in Nassau, The Bahamas simultaneously using a camera-based imaging lidar (CLidar). The bistatic geometry of the setup which consisted of a wide-angle lens fitted to a charge-coupled device (CCD) camera, allowed for the measurement of extinctions at all altitudes at once without requiring expensive timing electronics common to lidars. A case study was conducted on November 5, 2018. The top of the boundary layer beyond which aerosol extinction was nearly zero was detected at ~ three km above sea level. Due to the excellent resolution of the CLidar at lower altitudes, variations of aerosol concentrations within the boundary layer are efficiently detected. Optical depth was measured using the same CLidar camera at the same time, utilising star photometry, and was found to be 0.043 ± 0.040. The value falls within the range of assumed values of AOD near the regions obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite.","PeriodicalId":484073,"journal":{"name":"International Journal of Bahamian Studies","volume":"64 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saltwater intrusion into land is becoming more of a problem as sea levels rise across the globe. The Bahamas is highly susceptible to extreme weather events and climate change because the islands are low-lying and located in the Atlantic hurricane belt. Hurricane Dorian (2019) had a devastating impact on Grand Bahama Island: producing heavy rains of up to 30-40 cm and storm surges of about 8 m. The objective of this study was to analyse the soil salinity status in Wellfields 1 and 6 on the island of Grand Bahama to determine if the salinity had decreased in the three years following Hurricane Dorian. As expected, the study found that by 2022, soil salinity in the wellfields had decreased compared to levels recorded in the year after Hurricane Dorian. Soil analysis completed in October 2022 illustrated that soil salinity averaged 475.5 mg/kg for both Wellfield 1 and Wellfield 6 on the island of Grand Bahama.
{"title":"Assessment of Soil Salinity on Grand Bahama Post-Hurricane Dorian","authors":"Danica Stubbs, Aaliyah Adderley, Clare Bowen-O’Connor, Carlton Watson, Williamson Gustave","doi":"10.15362/ijbs.v29i1.507","DOIUrl":"https://doi.org/10.15362/ijbs.v29i1.507","url":null,"abstract":"Saltwater intrusion into land is becoming more of a problem as sea levels rise across the globe. The Bahamas is highly susceptible to extreme weather events and climate change because the islands are low-lying and located in the Atlantic hurricane belt. Hurricane Dorian (2019) had a devastating impact on Grand Bahama Island: producing heavy rains of up to 30-40 cm and storm surges of about 8 m. The objective of this study was to analyse the soil salinity status in Wellfields 1 and 6 on the island of Grand Bahama to determine if the salinity had decreased in the three years following Hurricane Dorian. As expected, the study found that by 2022, soil salinity in the wellfields had decreased compared to levels recorded in the year after Hurricane Dorian. Soil analysis completed in October 2022 illustrated that soil salinity averaged 475.5 mg/kg for both Wellfield 1 and Wellfield 6 on the island of Grand Bahama.","PeriodicalId":484073,"journal":{"name":"International Journal of Bahamian Studies","volume":"7 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134906978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the sparse distribution of buoys in the ocean, direct observations of extreme wave activity as excited by tropical cyclones (TCs) are few; but nonetheless, these buoys provide rare opportunities to learn more about how weather systems interact with the ocean wave field. In this study, National Oceanic and Atmospheric Administration National Data Buoy Center buoy observations of one-dimensional (1D) and two-dimensional (2D) wave spectra during the translation speed of Hurricane Dorian (2019) through the Atlantic Ocean were used to examine extreme wave events in the days before and after its September 1, 2019 landfall in The Bahamas. Observations of wave properties during storm intensification and decay showed that although significant wave height naturally rose and fell, the dominant wave period remained virtually constant. At the height of the storm, a lethal combination formed, with the highest significant wave heights being recorded at over 8 m (more than four times the mean) and dominant wave periods exceeded 12 s. Wave direction also varied widely as wave regimes shifted from wind-sea to swell, with spectral wave energy peaking at over 120 m2/Hz, six times higher than pre-Hurricane Dorian wave states. This study provides the first in situ characterization of extreme wave heights as induced by Hurricane Dorian. The study recommends that a number of observational platforms be funded, developed, and deployed throughout the Lucayan Archipelago.
{"title":"Observations of Extreme Waves and Wave Spectra during Hurricane Dorian (2019)","authors":"Brandon J. Bethel","doi":"10.15362/ijbs.v29i1.497","DOIUrl":"https://doi.org/10.15362/ijbs.v29i1.497","url":null,"abstract":"Due to the sparse distribution of buoys in the ocean, direct observations of extreme wave activity as excited by tropical cyclones (TCs) are few; but nonetheless, these buoys provide rare opportunities to learn more about how weather systems interact with the ocean wave field. In this study, National Oceanic and Atmospheric Administration National Data Buoy Center buoy observations of one-dimensional (1D) and two-dimensional (2D) wave spectra during the translation speed of Hurricane Dorian (2019) through the Atlantic Ocean were used to examine extreme wave events in the days before and after its September 1, 2019 landfall in The Bahamas. Observations of wave properties during storm intensification and decay showed that although significant wave height naturally rose and fell, the dominant wave period remained virtually constant. At the height of the storm, a lethal combination formed, with the highest significant wave heights being recorded at over 8 m (more than four times the mean) and dominant wave periods exceeded 12 s. Wave direction also varied widely as wave regimes shifted from wind-sea to swell, with spectral wave energy peaking at over 120 m2/Hz, six times higher than pre-Hurricane Dorian wave states. This study provides the first in situ characterization of extreme wave heights as induced by Hurricane Dorian. The study recommends that a number of observational platforms be funded, developed, and deployed throughout the Lucayan Archipelago.","PeriodicalId":484073,"journal":{"name":"International Journal of Bahamian Studies","volume":"11 3-4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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