Vertically-integrated tropospheric moisture, energy and their fluxes over Bangladesh during landfall of tropical cyclones

The changes in the vertically-integrated tropospheric moisture. energy and their fluxes over Bangladesh have been studied during the landfall of three major cyclones at Bangladesh coast in the recent past. It has been found that the vertically- integrated tropospheric moisture, dry static energy, latent energy and total energy over the country have a tendency to decrease at the formation stages of the cyclones in the Bay of Bengal and then the same shows significant increase as the cyclones move northwards for ultimate landfall. The integrated zonal and meridional fluxes of moisture, dry static energy, latent energy and total energy exhibit significant changes both in magnitudes and signs during the northward movement of the cyclones.

An Overview of Integrated Coastal Zone Management (ICZM) of Bangladesh

This research was conducted Bangladesh (BD) and revised as an especial task study and review perspective of the coastal conditions and the features thus determine and critical analysis of integrated coastal zone management (ICZM). The coast length of Bangladesh is 710 kilometers wide. The coastal and ecosystem and habitats of the different animals are mostly depend on the features of coastal ecology and data analysis of both countries which have different strategies and techniques for the conservation of coastal biodiversity which were focused and brought together. Bangladesh coast contains vast biodiversity which are supported by the shingle beaches & sand dunes. The main features of the physical characteristics are the creeks, a lot of channels with crossing line, deltas of Ganges tidal plan with very low topology and mangroves. Integrated Coastal Zone Management (ICZM) in Bangladesh are greatly different because of variation in advanced and developed technology and the system of the creating legislative recommendations also varies; which could determine changes in sea level and coastal resources as well as habitats. This study targets to detect the background of coastal zone management (ICZM), scope, coastal development, challenges, environmental impacts, and necessary measures. Now, integrated coastal zone management (ICZM) is used for coastal development strategy in BD.

Influence of humanitarian assistances on ecosystem services in Bangladesh coast

The coastal ecosystem of Bangladesh is diverse and the life and livelihood of the people are largely dependent on ecosystem services (ES). The frequent natural disasters negatively influence coastal ecosystem services and consequently interrupt human life and resources. Government and non-government organizations provide humanitarian assistance to the local community to recover damages induced by disasters in coastal areas. In this research, we used participatory workshops (n=4) and face-to-face questionnaire surveys (n=131) to study the influence of humanitarian assistance on ecosystem services on the Bangladesh coast. Our study revealed prominent ecosystem services in the study area; those were provisioning services: crops, livestock, capture fisheries, freshwater; regulating services: erosion regulation, climate regulation, natural hazard regulation; cultural services: recreation and tourism, boating to the Meghna coast, migratory birds watching. The livelihood of people was heavily impacted by the disasters; however, training support guided them to manage their income by selling their commercially produced animals (e.g., cattle, goats and poultry) before disaster seasons. Humanitarian assistance for supplementary nutrient supply, sanitation and drinking water facilities influenced the unwanted extraction of natural resources from the fragile ecosystems after the disaster. Our study suggested that future research should focus on the influence of one-to-one humanitarian assistance, to what extent ES improvement through this assistance is achievable for natural disaster protection on the Bangladesh coast.

WEATHER PERTURBATIONS ASSOCIATED WITH THE TRANSIT OF TROPICAL CYCLONES IN THE COAST OF BANGLADESH

During the transition of tropical cyclone in the coast of Bangladesh, it is normally observed that there is a noticeable perturbation of weather parameters around the cyclone landfall zone. Through this research the extent of perturbation is assessed. To make the inventory 4 recent cyclones were selected that had made landfall in Bangladesh coast. They are cyclone MORA, cyclone ROANU, cyclone KOMEN and cyclone MAHASEN. Weather parameters selected to check their perturbation are wind speed, temperature, dew point temperature, atmospheric pressure, relative humidity and precipitation. The dispersion of these parameters from their normal state was measured also in accordance of their distance from the landfall area. To perform the task a time scale of 15 days was selected for each cyclone. Middle 3 days window were considered as most affected weather, 6 days prior and after the event were considered as normal (prevailing) weather. The Synop (observed) data was downloaded from the Ogimet.com. The data was then processed and decoded by Synop decoder and then further analyzed in MS Excel. In case of atmospheric pressure perturbation the highest perturbation was found 5.8 mb low on average than prevailing pressure up to 50 km from cyclone landfall. Wind speed perturbation was highest in 50 to 100 km area. Perturbation of temperature was highest in 0 to 50 km (about 2.1 °C low on average). Perturbation of dew point temperature was found negligible and humidity perturbation was found highest 6.63% high on average up to 50 km of landfall. In case of precipitation perturbation highest was found in 0 to 50 km area of landfall (38.76 mm high on average than prevailing weather), however precipitation perturbation was irregular beyond 100 km of landfall. The most perturbed weather parameter was found atmospheric pressure and the least affected was dew point temperature.

Development of a Matrix Based Statistical Framework to Compute Weight for Composite Hazards, Vulnerability and Risk Assessments

Selection of relative weights for different indicators is a critical step during assessment of composite hazards, vulnerability, and risk. While assigning weight to an indicator, it is important to consider the influence of an individual indicator on a particular composite index. In general, the larger the weight of the indicator, the higher the importance of that indicator compared to other indicators. In this study, a new matrix based statistical framework (MSF) for weight assignment is developed that can be considered as the simplest and most accurate method for assigning weights for a large number of indicators. This method (MSF) is based on the valuation of the correlation matrix and Eigenvector associated with Eigenvalue. Relying on the inter build up methodology, MSF can fulfill some built-in gaps among other weightage methods. It can also directly give the ‘decision’ to select the relative weights that are found from the Eigenvector corresponding to the largest Eigenvalue. The new method is applied by assigning weights to 15 socio-economic indicators and assessed vulnerability and risk in the Bangladesh coast. While comparing with other weight methods, it is found that MSF gives the most acceptable physical explanation about the relative values of weights of indicators. In terms of accuracy, MSF is found to be most accurate compared to other weight methods. When large numbers of indicators are involved in an application, MSF is found to be relatively simple and easy to apply compared to other methods.