Air pollution presents a significant challenge in Bangladesh, particularly in its capital, Dhaka, which ranks among the world's least livable cities. The prevalence of PM_2.5, a prominent air pollutant, has dire health consequences for the nation's residents. This study investigated the intricate relationship between elevated levels of PM_2.5 and mortality rates linked to diseases such as Ischemic Heart Disease (IHD), Chronic Obstructive Pulmonary Disease (COPD), Cerebrovascular Disease (CVD), Lower Respiratory Infections (LRI), and Lung Cancer (LC). This study utilized station data (2012-2022) and gridded data (2000-2021) for PM_2.5, gridded population data (2000-2022) and cause-specific base mortality rate of 2019 for Bangladesh. It explored the diurnal, seasonal, and annual variability of PM_2.5 concentrations throughout the country. Relative risk and disease-specific mortality rates were estimated using the Integrated Exposure-Response (IER) and Global Exposure Mortality Model (GEMM). The results revealed large disparities in disease burden among geographic regions and timeframes. PM_2.5 levels were generally low in the early morning and high in the late afternoon in all cities, except for some locations in Dhaka, where they were high at night. Seasonal variability revealed that pollution in winter was more than three times higher than in the monsoon season. Air pollution in Dhaka remained higher than WHO standard limits in almost all seasons, except for a few hours during peak monsoons. Very few stations in the country exhibited less than 5 μg/m³ of PM_2.5 at the 24-hour level. Higher PM_2.5 concentrations, especially in major cities, were linked to increased excess mortality rates for the mentioned diseases. This study can enhance our comprehension of the public health consequences of ambient air pollution in Bangladesh, which necessitates further extensive exploration.

The Old Brahmaputra Floodplain of Bangladesh frequently faces the severity of floods during the monsoon because of its geographical location through the low-lying land with dynamic morphological behavior due to an immense load of upstream discharges. This research focuses on the significant parts of the Old Brahmaputra Floodplain (Mymensingh, Jamalpur, and Sherpur Sadar Upazila) because of the destructive flooding history. This study aimed to generate a comprehensive micro-scaled flood hazard map using the HEC-RAS (Hydrologic Engineering Center's River Analysis System) coupled with 1D-2D numerical modeling approaches in a quantitative way for different time intervals (10, 20, 50 & 100 years) based on the discharge hydrograph generated after the frequency analysis using the HEC-SSP (Hydrologic Engineering Center's Statistical Software Package). Log-Pearson Type III distribution has been used for frequency analysis to estimate the peak discharge for the different return periods. After performing the Unsteady Flow simulation for the model, calibration and validation have been performed for the 1D model concerning the observed water level of Mymensingh station (SW228.5). Finally, flood hazard maps were produced performing Unsteady Flow simulation of the coupled 1D-2D model for different return periods (5, 10, 20, 50, and 100 years) showing flood extent, water depth, velocity, maximum arrival time, and duration for each return period which is one of the most widely used ways to identify vulnerable areas and exposures to floods so that the authorities can take the necessary precautions for those exposures to minimize the losses and flood risk. Therefore, this study will help generate a more comprehensive flood hazard map of the Old Brahmaputra River to strengthen the existing flood risk management policies and protection measures.

The land surface temperature of Chattogram city in Bangladesh increased more quickly than that of the surrounding areas due to changes in land use, rapid urbanization, and population growth. Consequently, identifying Urban Heat Islands (UHI) or climatic change in the region was the main goal of this study. Changes in the city's day and nighttime temperatures were analyzed, and their link to urban sprawl was investigated. Trends in urban areas and surrounding temperature rise were examined in order to distinguish between temperature rise caused by UHI and global warming. The MODIS Land Surface Temperature (LST) (2000-2021) data were used for this purpose. R programming software was used to download, preprocess, analyze, and visualize data. Modified Mann-Kendal (MMK) test and sen's slope estimator were used to assess the trends of UHI and LST. The urban expansion curve, urban nightlight maps from various years, and the urban spreading map revealed the city's rapid growth over time. The results revealed that urban temperature has increased throughout the year. Based on the study's findings, it can be stated with confidence that urban sprawling seriously impacts UHI and the microclimate of Chattogram city. This finding allows us to compare and see that LST is rising over time due to urbanization and the shrinking amount of naturally vegetated areas. The present study did not offer a forecast for the future due to time restrictions. Further research may be utilized to forecast the Land Surface Temperature, and upcoming UHI trends and identify mitigation strategies. This study could provide information on the effects of urbanization on the microclimate, which could help with urban developmental projects.

Fire hazards are a common occurrence posing a significant threat to life, property, and the environment in Bangladesh. Fire events in Bangladesh have caused numerous fatalities resulting in significant economic losses. In recent years, an increase in the frequency and severity of fire events in the country has been seen highlighting the need for improved fire management strategies. This study has developed a simulated model of the Sitakunda Fire Event on June 4th, 2022. Two simulated scenarios were created based on the incident scene, one replicating the actual event and the other simulating the potential outcome if the H₂O₂ container was absent. The location of the fire origin and surrounding objects were mapped, and three software programs, PyroSim, Fire Dynamic Simulator (FDS), and SmokeView (SMV), were utilized to create the models. The outputs generated multiple time series plots that depicted the fire's characteristics and behavior. The first scenario showed higher levels of heat released, temperature, and oxygen density, resulting in reduced visibility compared to the second scenario. The study's findings offer valuable insights into sustainable management and response activities to fire incidents in Bangladesh. Furthermore, the results can serve as a useful model for future fire scenarios, providing guidance on mitigation and preparedness measures to be implemented in locations prone to such risks. Overall, this study presents a comprehensive understanding of the Sitakunda Fire Event, which can aid in the formulation of effective response strategies to tackle such incidents in the future. The research serves as a significant contribution to the field of fire safety and highlights the need for better preparedness and management in locations prone to such risks.

Situated at the heart of the Dhaka city, Mohakhali is a major transportation hub which connects the city with the other cities around the country. Although it is a major central hub for transportation, it is also infamous for traffic congestion in the city. Due to the lack of adequate planning, the buses entering and exiting from this terminal causes a massive gridlock on the road situated in front of it. The purpose of this study is to identify the problems and find reasonable solutions to this traffic jam and improve the accessibility of the buses and other vehicles in the area. By achieving this, the traffic situation of the area, if not the whole city, can be assuaged quite significantly.

The problem surrounding the Mohakhali bus terminal is increasing day by day causing disruption in the day to day lives of the city dwellers in the vicinity. Not only does it causes traffic congestion but with this problem comes the situation of wastage of time, pollution, frustration and not to mention the most severe of all problems, road accidents. The situation has gone so much out of hand that the people of the city now consider this a constant part of their lives. This area has now become a nightmare for the people of Mohakhali and the people commuting through it. The major problem of the Mohakhali bus terminal is its poor planning and handling of the vehicles. Parking (single and double lane of buses) on the road is a major issue as it hampers the passing of other vehicles. The parking situation inside is also in shambles as it is unplanned and buses are parked as they please. There is also no specific drop-off or pick-up space of passengers for the buses inside and outside the terminal, people board the buses from the main road and also bus drivers stop the buses to pick passengers wherever and whenever they please. Mohakhali is a connection of the capital with the other cities in the country. It is the location of a terminal dated back from the 80’s and has created its own significance as a major transportation hub. Mohakhali is one of the four major bus terminals in the Dhaka city; therefore it is also one of the major attraction points for thousands of buses, cars, motorized and non-motorized vehicles and people. This area also attracts a lot of unwanted traffic jam, and corruption. Unplanned parking, insufficient bus bays, lack of distinction between pedestrian and vehicular circulations is also major problems associated with this site.

The problem has now become so severe that the Dhaka North City Corporation has taken initiatives to completely uproot all the bus terminals inside the city and place them outside the city boundaries. They are planning to replace the existing bus terminal with a bus depot which will house buses, develop a bus stop along with developing commercial and recreational spaces. The existing terminal lacks proper basic facilities such as, bus docks, proper ticket counters, clean and hygienic waiting area and washrooms. Buses are parked haphazardly inside the area which is supposed to be a depot to accommodate 300 buses but due to poor management can house barely 100 buses, therefore resulting in the buses parking outside the terminal. In the Revised Strategic Transport Plan (RSTP) report (2019), it is mentioned that the Mohakhali bus terminal falls along the BRT Line-3 making it a bus stop as well. According to DTCA (Dhaka Transport Coordination Authority, 2021) and RSTP (Revised Strategic Transport Plan) the existing terminal in Mohakhali is to be demolished and made into a bus stop, depot and commercial space.

Revitalizing the commercial essence of Mohakhali bus terminal site through uninterrupted accessibility of all activity to increase the connection between the site and its surrounding community is a start to assuage this situation. Separation of modes outside of site and integration between the modes inside to avoid overlapping of different circulations (such as car, bus, pedestrian, rickshaw, CNG etc.) can also be considered to ensure safe passage of both vehicles and pedestrians. One of the major issues of the Mohakhali Bus Terminal is its lack of public accessibility. The only entry to the terminal is by crossing through the buses that are parked, with only a 2 story small building for passengers to wait and a few ticketing booths.

A multi-storied (underground) indoor bus parking can be proposed to separate the different modes of transportation. By doing so, the ground floor can be made completely accessible for public use by redeveloping the area into a recreational spot through proper planning. The buses can be parked and serviced in to the underground three floors, ticketing areas and waiting rooms can be positioned in the ground floor and shopping complexes and Cineplex’s can be made available on the upper floors. The indoor bus parking can be proposed to accommodate spaces under and above the ground, with ramps to reach the different levels of bus parking. This option will allow the vehicles to have a controlled circulation within the terminal area. Also the urban spaces outside the terminal can be utilized as a recreational spot for the people in the neighborhood and other parts of the city. By boosting its commercial and recreational attributes, the problematic Mohakhali bus terminal can be turned into a major attraction area of the city.

The Sarushima Battery Ruins located in Yokosuka Port has been over 130 years since its completion in 1884, and deterioration has been observed in the brick structures. Yokosuka City conducted a survey with Asano Taisei Engineering Co., Ltd. in order to restore and preserve historic sites and ensure the safety of visitors to Sarushima, which is also used as a city park. We used 3D laser scanners, UAVs, etc. for the investigation.

Recently, a water spring was observed in the west brick wall of the fortress tunnel. A depression is formed on the west side of the tunnel. It was thought that rainwater may be stagnant in this depression and spring water may be flowing into the west brick wall. The investigation included three-dimensional laser scanner displacement measurement, structure inspection, core extraction, lining thickness, wall thickness and back cavity investigation, topographical and geological exploration, and maintenance methods for preservation were considered.

As a result of the investigation, the results of laser scanner measurements are illustrated. For preservation consideration, developed, cross-sectional, and elevation drawings of the tunnel, ammunition depot, and habitat cover were created. The results of the structural inspection survey were recorded as a damage development map in the development map created this time. Spring water was observed in two holes drilled in the defective side wall of the horizontal part of the tunnel, but the water stopped flowing after about 5 to 20 minutes, which is thought to be caused by water stagnant in the depression.

Based on the survey results, it is recommended to carry out routine long-range visual inspections focusing on water leakage conditions and areas at risk of spalling, regularly check for changes in deformation over time using a 3D laser scanner, and check for damage progress through close-up visual inspections.