International journal of applied earth …, Jan 1, 2004
This study aims to prepare a detailed GIS-based geomorphological map accompanied with landfill si... more This study aims to prepare a detailed GIS-based geomorphological map accompanied with landfill sites of Dhaka city area which can be used for multipurpose functionality. Attainment of the geomorphological map is based upon interpretation of the oldest available aerial photographs (1:40,000) and contemporary topographic maps (1:8000) which reflect almost pre-urban ground of Dhaka. Randomly distributed 160 boreholes have been used to prepare representative soil profiles (RSP) to identify the near-surface lithology of the geomorphological units. The study reveals that 13 out of 18 low-lying geomorphic units, comprising 65% of the total area demand landfill practices for urban development. Landfill sites have been merged with urban growth on each low-lying geomorphic unit using a spatially enhanced fused image of IRS-1D PAN and ETM+ bands 5, 4 and 3, acquired February 2000 and 2002, respectively. We found that 43% area of the total low-lying geomorphic units experience fill practices so far. The fill sites have been differentiated into four classes based on their relative thickness. Integration of fill classes with geomorphological map shows the urban dynamics of Dhaka city area till 2002. Due to GIS integration, this map can be rapidly updated to demonstrate temporal modifications in urban ground. It can be used effectively in different geomorphological hazard mapping and urban land-use practices. #
The time varying forces in the ground generates earthquake loads and the pattern of load specifie... more The time varying forces in the ground generates earthquake loads and the pattern of load specified as a time history of ground excitation is the most accurate means of representing earthquake actions. The difficulty with carrying out analysis procedures to compute the responses of a structure for this type of load is that the form of the acceleration time history is to be clearly known. As there is lack of earthquake data for Dhaka, Bangladesh, which is in risk of attack by severe earthquakes, the engendering earthquake time history data of this region for precise dynamic analysis is of utmost importance. So, the objective of this research is to develop the reliable Dhaka earthquake time history, functioning as a competent seismic record. Seismic data have been measured in-situ with proper seismographic instruments at the recently occurred local earthquake near the Dhaka vicinity. Choosing the nearby seismic record, probable acceleration time history of Dhaka has been properly scaled as per the seismicity and ground acceleration characteristics of its own, following the widely accepted Bangladesh National Building Code (BNBC). Generated EQ time history is then evaluated with the prominent seismic records available in literature. This seismic data essentially yield the responses at every little incremental state of numerous time extents. The research acquaints us with suitable Dhaka earthquake time history data which can be reliably exploited as advance future seismic record.
Bangladesh is vulnerable to seismic events. Experts suspect that if an earthquake with a 7.0 magn... more Bangladesh is vulnerable to seismic events. Experts suspect that if an earthquake with a 7.0 magnitude occurred in large cities of Bangladesh, there would be a major human tragedy due to the structural failure of many buildings. The primary objectives of this paper are to examine seismic risk perception among residents of Dhaka City and investigate their levels of earthquake preparedness. A questionnaire survey conducted among 444 residents of the city provided the major source of data for the paper. The survey results suggest that an overwhelming majority of the respondents were not prepared for a major earthquake, which is anticipated to occur in Dhaka. Multivariate analysis of survey data reveals that value of residential unit and respondent educational levels appear as the most significant determinants of preparedness status of the respondents. This study recommends increasing earthquake awareness and preparedness among residents of Dhaka City.
International journal of applied earth …, Jan 1, 2004
This study aims to prepare a detailed GIS-based geomorphological map accompanied with landfill si... more This study aims to prepare a detailed GIS-based geomorphological map accompanied with landfill sites of Dhaka city area which can be used for multipurpose functionality. Attainment of the geomorphological map is based upon interpretation of the oldest available aerial photographs (1:40,000) and contemporary topographic maps (1:8000) which reflect almost pre-urban ground of Dhaka. Randomly distributed 160 boreholes have been used to prepare representative soil profiles (RSP) to identify the near-surface lithology of the geomorphological units. The study reveals that 13 out of 18 low-lying geomorphic units, comprising 65% of the total area demand landfill practices for urban development. Landfill sites have been merged with urban growth on each low-lying geomorphic unit using a spatially enhanced fused image of IRS-1D PAN and ETM+ bands 5, 4 and 3, acquired February 2000 and 2002, respectively. We found that 43% area of the total low-lying geomorphic units experience fill practices so far. The fill sites have been differentiated into four classes based on their relative thickness. Integration of fill classes with geomorphological map shows the urban dynamics of Dhaka city area till 2002. Due to GIS integration, this map can be rapidly updated to demonstrate temporal modifications in urban ground. It can be used effectively in different geomorphological hazard mapping and urban land-use practices. #
The time varying forces in the ground generates earthquake loads and the pattern of load specifie... more The time varying forces in the ground generates earthquake loads and the pattern of load specified as a time history of ground excitation is the most accurate means of representing earthquake actions. The difficulty with carrying out analysis procedures to compute the responses of a structure for this type of load is that the form of the acceleration time history is to be clearly known. As there is lack of earthquake data for Dhaka, Bangladesh, which is in risk of attack by severe earthquakes, the engendering earthquake time history data of this region for precise dynamic analysis is of utmost importance. So, the objective of this research is to develop the reliable Dhaka earthquake time history, functioning as a competent seismic record. Seismic data have been measured in-situ with proper seismographic instruments at the recently occurred local earthquake near the Dhaka vicinity. Choosing the nearby seismic record, probable acceleration time history of Dhaka has been properly scaled as per the seismicity and ground acceleration characteristics of its own, following the widely accepted Bangladesh National Building Code (BNBC). Generated EQ time history is then evaluated with the prominent seismic records available in literature. This seismic data essentially yield the responses at every little incremental state of numerous time extents. The research acquaints us with suitable Dhaka earthquake time history data which can be reliably exploited as advance future seismic record.
Bangladesh is vulnerable to seismic events. Experts suspect that if an earthquake with a 7.0 magn... more Bangladesh is vulnerable to seismic events. Experts suspect that if an earthquake with a 7.0 magnitude occurred in large cities of Bangladesh, there would be a major human tragedy due to the structural failure of many buildings. The primary objectives of this paper are to examine seismic risk perception among residents of Dhaka City and investigate their levels of earthquake preparedness. A questionnaire survey conducted among 444 residents of the city provided the major source of data for the paper. The survey results suggest that an overwhelming majority of the respondents were not prepared for a major earthquake, which is anticipated to occur in Dhaka. Multivariate analysis of survey data reveals that value of residential unit and respondent educational levels appear as the most significant determinants of preparedness status of the respondents. This study recommends increasing earthquake awareness and preparedness among residents of Dhaka City.
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Papers by Sajeeb Rahman