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In Bangladesh flood mitigation strategies have concentrated on embankments. However, due to a perceived lack of success with this strategy and high returns to irrigation development, the emphasis in water management switched towards small scale irrigation. Serious floods in 1987 and 1988 have renewed interest in flood mitigation. However, there is a lack of detailed evidence on the impacts of embankments. This study provides just such evidence. The study comprises a detailed post-evaluation of a major flood control, drainage and irrigation project, the Chandpur Irrigation Project. The results show that the project has been successful in reducing normal monsoon water levels, with consequent changes in cropping patterns to higher yielding varieties. However, a with-without comparison revealed that expected yields (allowing for risks of flooding and drainage problems) were less than predicted due to drainage problems within the project, whereas non-project expected yields are as predicted. Hence agricultural output has increased substantially, but output and its value are less than anticipated. Household incomes in the project are 25&37 higher (on average) than in control areas, but this is because larger landowners have gained from greater returns to agriculture (for example, from preferential access to irrigation), and diversifying into other occupations. Some households have gained by selling land and obtaining salaried jobs elsewhere or by becoming traders. By comparison small landowners may be slightly less prone to losses in flood years but have not moved into surplus. Landless labourers have similar incomes inside and outside the project; real wages are unchanged, and increased work has not compensated for population growth. Inside the project changes in landholding category have been fewer than outside. Open water fish populations have been reduced by the embankment, particularly affecting poor households. However, fish cultivation has expanded more than in flood prone areas, benefiting pond owners and enabling professional fishermen to maintain their incomes (at the cost of greater dependence on larger landowners). Improved methods of post-evaluation (which have implications for appraisal of new projects) are developed to incorporate flood risks and consequent yield reductions and non-agricultural damages, and to standardise economic valuation. Applying these methods revealed that the Chandpur Project has been, despite an uneven distribution of benefits, relatively successful (an economic rate of return of at least 5%). Although there are some project specific reasons for this success, this project has suffered many problems typical of embankment in Bangladesh. Hence embankments are potentially important for the future economic development of Bangladesh - by reducing damage and disruption and increasing agricultural output. The study concludes with recommendations for improved flood plain planning in Bangladesh, using detailed flood loss data and improved appraisal methods, to ensure that choice of flood mitigation strategies and investments are rational, and that all public investments take flood risks into account.

Affected by unprecedented urban growth, overcrowding, poverty, and health inequalities, Bangladesh has remained hyperendemic for dengue since 2000. Considering the complexities involved with dengue transmission, I argued that understanding transmission requires encapsulating different disciplinary knowledge as well as non-academic knowledge. I have applied an Ecohealth approach to investigate dengue transmission dynamics in Dhaka, Bangladesh. Using the Delphi method, all 90 Wards of Dhaka were classified into ‘high’, ‘medium’, and ‘low’ Socio-Economic Status (SES) zones. A total of 1,200 households were randomly selected which represented the SES zones. During 2011-2012, these sampled households were repeatedly inspected for Aedes mosquitoes and to collect blood samples from residing members. This transdisciplinary investigation focused on: i) the rates of human exposure to dengue virus (DENV) by identifying individuals with IgM and IgG antibodies in the serosurvey samples; ii) abundance of dengue vector mosquitoes (Aedes aegypti) in the same households; iii) risk perception, and Knowledge, Attitude and Practice (KAP) regarding dengue among community members and experts. KAP survey results indicated that 93.7% of the community members knew that mosquitoes act as the primary vector of its transmission; 87.3% were unaware that Aedes mosquitoes prefer to lay their eggs in water containers. The entomological survey results showed that 26.7% of all surveyed houses in the city were infested with Aedes aegypti mosquitoes. The ornamental functional categories of containers were most significant containers in producing maximum number of Aedes pupae; this was found to be a significant risk factor for seroprevalence and seroconversion. The examination of IgG seroprevalence revealed that seropositivity was strongly correlated with increased age and number of indoor potted plants. The serosurvey findings showed that seroprevalence was high (79.9%), revealing that most dwellers had been exposed DENV. However, there was no significant association between Aedes positive houses and houses with seroconverted persons, indicating that people were being infected in distant areas outside their houses. A persistently high rate of dengue infection in Dhaka is being influenced by the lack of knowledge and awareness of the eco-bio-social factors. Improvement in intersectoral coordination to formulate and implement dengue epidemic prevention and control interventions is necessary. / May 2015

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: p. 82-83. / by Aminul Haq Khan. / M.S.

This thesis explores urban poverty and the adaptations of the urban poor in the slums of the megacity of Dhaka, Bangladesh. It seeks to make a contribution to understanding and analysis of the phenomenon of rapid mass urbanisation in the Third World and its social consequences, the formation of huge urban slums and new forms of urban poverty. Its focus is the analysis of poverty which has been overwhelmingly dominated by economic approaches to the neglect of the social questions arising from poverty. This thesis approaches these social questions through an ???urban livelihood framework???, arguing that this provides a more comprehensive framework to conceptualise poverty through its inclusion of both material and non-material dimensions. The study is based on primary data collected from slums in Dhaka City. Five hundred poor households were surveyed using a structured questionnaire to investigate the economic activities, expenditure and consumption, access to housing and land, family and social networking and cultural and political integration. The survey data was supplemented by qualitative data collected through fifteen in-depth interviews with poor households. The thesis found that poverty in the slums of Dhaka City was most strongly influenced by recent migration from rural areas, household organisation, participation in the ???informal??? sector of the economy and access to housing and land. Almost half of the poor households in the study locations were identified as ???hardcore poor???, that is having insufficient income for their physical needs. The remainder were found to be ???absolute poor???, those who experienced poverty and vulnerability but varied in their levels of income and consumption. This level of poverty was also characterised by their social, cultural and political marginalisation. In summary, the urban poor remain very much dependent on their household and social networking, the main social capital they use to adapt to life in Dhaka City. Overall, the urban poor in this study experience the highest level of poverty and vulnerability in their everyday life. The thesis argues that the experience of poverty in the megacity of Dhaka for these households follows the pattern of urbanisation without development, the very opposite to their expectations and aspirations.

Bibliography: leaves 106-114.

An examination of suspended sediment concentrations throughout the Ganges-Brahmaputra River System was conducted to assess the spatial variability of river sediment in the world’s largest sediment dispersal system. During the high-discharge monsoon season, suspended sediment concentrations vary widely throughout different geomorphological classes of rivers (main river channels, tributaries, and distributaries). An analysis of the sediment loads in these classes indicates that 7% of the suspended load in the system is diverted from the Ganges and Ganges-Brahmaputra rivers into southern distributaries. Suspended sediment concentrations are also used to calculate annual suspended sediment loads of the main river channels. These calculations show that the Ganges carries 262 million tons/year and the Brahmaputra carries 387 million tons/year. These calculations are lower than published values because of either interannual variability and/or sampling artifacts and assumptions in the homogeneity of flow and sediment concentration. The conjoined Ganges-Brahmaputra River carries 530 million tons annually, or only 80% of the sum of the loads that the Ganges and Brahmaputra rivers carry upstream of the confluence. The remaining 20% of sediment is diverted from the main river by the distributaries and deposited along the main river channel during overbank flooding. Suspended sediment concentration is also examined in the north-south oriented tidal channels on the Bay of Bengal to determine whether sediment is delivered to the channels by one of two pathways: (1) sediment is discharged into the Bay of Bengal by the main river channel, carried west by coastal currents, and advected northward into the channels by tidal currents or (2) diverted from the main river bed through the distributaries, migrating southward into the tidal channels. Suspended sediment concentration and salinity data are inconclusive in determining sediment source. Beryllium-7 radioisotope data indicate that newly transported sediment is present in the tidal channels and offshore despite values in the Ganges and Ganges-Brahmaputra rivers being below detection. Sampling artifacts are likely caused by the below detection readings in the Ganges and Ganges-Brahmaputra rivers. Newly transported sediment is observed in a distributary south of the Ganges River and indicates that sediment is actively being transported to the distributary region.

An examination of suspended sediment concentrations throughout the Ganges-Brahmaputra River System was conducted to assess the spatial variability of river sediment in the world’s largest sediment dispersal system. During the high-discharge monsoon season, suspended sediment concentrations vary widely throughout different geomorphological classes of rivers (main river channels, tributaries, and distributaries). An analysis of the sediment loads in these classes indicates that 7% of the suspended load in the system is diverted from the Ganges and Ganges-Brahmaputra rivers into southern distributaries. Suspended sediment concentrations are also used to calculate annual suspended sediment loads of the main river channels. These calculations show that the Ganges carries 262 million tons/year and the Brahmaputra carries 387 million tons/year. These calculations are lower than published values because of either interannual variability and/or sampling artifacts and assumptions in the homogeneity of flow and sediment concentration. The conjoined Ganges-Brahmaputra River carries 530 million tons annually, or only 80% of the sum of the loads that the Ganges and Brahmaputra rivers carry upstream of the confluence. The remaining 20% of sediment is diverted from the main river by the distributaries and deposited along the main river channel during overbank flooding. Suspended sediment concentration is also examined in the north-south oriented tidal channels on the Bay of Bengal to determine whether sediment is delivered to the channels by one of two pathways: (1) sediment is discharged into the Bay of Bengal by the main river channel, carried west by coastal currents, and advected northward into the channels by tidal currents or (2) diverted from the main river bed through the distributaries, migrating southward into the tidal channels. Suspended sediment concentration and salinity data are inconclusive in determining sediment source. Beryllium-7 radioisotope data indicate that newly transported sediment is present in the tidal channels and offshore despite values in the Ganges and Ganges-Brahmaputra rivers being below detection. Sampling artifacts are likely caused by the below detection readings in the Ganges and Ganges-Brahmaputra rivers. Newly transported sediment is observed in a distributary south of the Ganges River and indicates that sediment is actively being transported to the distributary region.