On November 15, 2007, Bangladesh was hit by the category 4 storm Severe Cyclonic Storm Sidr. At least 3,447 deaths were reported in coastal areas of Bangladesh, mainly owing to the storm surge, which was >5 m. A study team of several faculty members of Bangladesh University of Engineering and Technology (BUET) was formed to visit areas affected by Sidr, two months after the storm. It was found that cyclone shelter capacities were inadequate for the population of the service area. Without shelters, many livestock animals died during the disaster. Many people neglected cyclone warnings, which resulted in many deaths. To improve cyclone shelter performance, this study makes many recommendations, including building more cyclone shelters, providing shelters for livestock, and improvement of warning systems.
1 September 2021 in Environmental Research Communications
River pollution through the discharge of untreated sewage and industrial effluent is a perverse outcome of rapid urbanisation and economic growth across Asia. To understand the socio-spatial and seasonal inequalities in pollution risks, we designed a direct observation method to record people’s daily river use activities across dry and wet seasons, complemented by monthly monitoring of river water quality, heavy metal and biotoxicity assessment a large-scale household survey along a 25km stretch of the Turag River and Tongi Khal in Dhaka, Bangladesh. We found very high ammonia and almost zero dissolved oxygen during the low flow season, further exacerbated by heavy metals from the annual Bishwa Ijtema gathering and downstream industrial zones. Pollution exposure through domestic activities prevailed throughout the year, particularly for women and girls along low-income settlements lacking adequate water and sanitation facilities. Swimming peaked among men and children in the monsoon, risking exposure to pathogen pollution. Recognising the social inequalities in risk can support the sequencing of policy action involving short-term adaptation (improved services, education, advocacy) and long-term mitigation (effluent treatment, regulation and enforcement) responses.
The impact of cyclone track features (e.g., cyclone translation speed, cyclone path and cyclone landfall crossing angle) in combination with tidal phase shift upon surge characteristics have been investigated at the Bay of Bengal along the Bangladesh coast. A two-dimensional hydrodynamic model in a horizontal direction (2DH) coupled with a storm-surge model has been employed for the study. Numerical experiments with three different cyclone translation speeds show that when the surge height is directly forced by the cyclonic wind speed especially within the RWM (Radius of Maximum Wind), faster translation speed produces reduced surge height as the cyclone gets less time to force the water. On the other hand, at locations outside the RMW, surge waves travel as a propagating long wave where higher surges are produced by faster moving cyclones. It is found that surge arrival times are more and more affected by tidal phase when cyclone translation speed is reduced. Analysis of seven hypothetical parallel cyclone paths show that local bathymetry and complex coastline configurations strongly influence the surge height and surge arrival time along the Bangladesh coast. From the analyses of cyclone landfall crossing angles at the Khulna and Chittagong coasts, it is observed that surge durations are the smallest at both the coasts when the coastline crossing angles are the smallest.