Dhaka city water logging hazards: area identification and vulnerability assessment through GIS-remote sensing techniques.

Water logging is one of the most detrimental phenomena continuing to burden Dhaka dwellers. This study aims to spatio-temporarily identify the water logging hazard zones within Dhaka Metropolitan area and assess the extent of their water logging susceptibility based on informal settlements, built-up areas, and demographical characteristics. The study utilizes integrated geographic information system (GIS)-remote sensing (RS) methods, using the Normalized Difference Vegetation Water and Moisture Index, distance buffer zone from drainage streams, and built-up distributions to identify waterlogged zones with a temporal extent, incorporating social and infrastructural attributes to evaluate water logging effects. These indicators were integrated into an overlay GIS method to measure the vulnerability level across Dhaka city areas. The findings reveal that south and south-western parts of Dhaka were more susceptible to water logging hazards. Almost 35% of Dhaka belongs to the high/very highly vulnerable zone. Greater number of slum households were found within high to very high water logging vulnerable zones and approximately 70% of them are poorly structured. The built-up areas were observed to be increased toward the northern part of Dhaka and were exposed to severe water logging issues. The overall findings reveal the spatio-temporal distribution of the water logging vulnerabilities across the city as well as its impact on the social indicators. An integrated approach is necessary for future development plans to mitigate the risk of water logging.

An overview of progress towards implementation of solid waste management policies in Dhaka, Bangladesh.

OBJECTIVES: Considering the increased solid waste generation and its management, this paper aims at reviewing and identifying the gaps and challenges in implementing the existing solid waste management relevant policies, strategies and action plans in Bangladesh for providing further strategic recommendations to establish a sustainable waste management system. METHODS: This study adopted a multi-method approach by reviewing 24 policy/strategy documents; implementation gap analysis with extensive desk review and data obtained from the qualitative approach and co-production workshop. It allowed this study to capture the multidimensional and comprehensive scenario of waste management in Dhaka city. RESULTS: Bangladesh has undergone reforms in solid waste management since 1983 with the adoption of the Dhaka City Corporation Ordinance and the enactment of the National 3R Strategy in 2010. With few exceptions, the overall waste management system cannot be defined as an effective comprehensive waste reduction, recycling and disposal mechanism based on global standards. Study found that several action plans have been introduced yet not all of those have proper implementation like adhering the waste segregation and recycling practices from households to landfill level. Lack of monitoring and coordination among the existing policy implementing agencies have emerged as significant concerns in Bangladesh. CONCLUSION: Challenges in the implementation of pragmatic and improved policies and strategies should be addressed.

Dhaka landfill waste practices: addressing urban pollution and health hazards.

Two Dhaka, Bangladesh, landfills are explored to understand how management practices impact environmental quality and public health in the surrounding areas. A combination of research methods is used, such as geospatial buffer zone analysis, semi-structured observation checklist and qualitative interviews, to gain an understanding of the waste transportation, leachate percolation, and adverse health and environmental effects. A multi-ring buffer zone and ground truth method were applied through ArcMap for the spatial distribution of landfill-adjacent environmental features. Qualitative interviews were conducted with landfill officials and nearby residents. Findings reveal that landfills are situated very close to residential areas, water bodies and agricultural lands, exposing them to various health and environmental hazards. Improper solid waste management practices of the landfills cause adverse environmental effects by leachate percolation, waste incineration and vector breeding. Adjacent dwellers suffer from bronchial diseases, pneumonia, diarrhoea, itching problems, headache and appetite loss. The existing solid waste management system requires managerial and technical modifications to reduce the associated environmental pollution and health hazards.