Subhendu Roy

Urban flooding of Greater Dhaka in a changing climate : building local resilience to disaster risk

Dhaka, the capital of Bangladesh and one of the world’s rapidly growing megacities, is an urban hotspot for climate risks. Preparing for the unfolding impacts of climate-related changes – socio demographic, environmental, economic, and political - is a daunting task. It requires that Dhaka’s policymakers, like those in other megacities of South Asia’s low-lying deltas, understand how climate change is anticipated to affect natural hazards that lead to flooding in the cities. This study’s overall aim is to provide local decision-makers an effective planning approach for minimizing the damage risk of rainfall-induced urban flooding in Dhaka in a changing climate. Specific objectives are to assess the vulnerability of the Greater Dhaka area to urban flooding and waterlogging, estimate probable economic damage due to climate change, develop structural adaptation measures, evaluate the reduction in economic damage resulting from implementing these measures, and estimate their cost. The study comprises four main activities: (a) hydrological modeling and development of adaptation measures, (b) spatial ranking of flood vulnerability, (c) evaluating expected damage from flooding, and (d) estimating adaptation costs. This book is divided into two major parts: study methods (part 1) and results (part 2). Part one is organized into four chapters. Chapter two presents the conceptual framework for the hydrological modeling study and the method and processes used to model future scenarios. Chapter three presents the seven model setups for the detailed study area. Chapter four describes the method used to assess the modeled areas’ relative vulnerability to urban flooding, while chapter five explains the method used to estimate their economic damage. Part two, also organized into four chapters. Chapter six provides the study results for each of the seven modeled areas, while chapter seven summarizes the overall study results for Dhaka city. Chapter eight turns to the secondary flood-mitigation measures that can complement the recommended conveyance-centric solutions. Chapter nine suggests a way forward.

Health Costs and Benefits of Ddt Use in Malaria Control and Prevention

The Millennium Development Goal of achieving near-zero malaria deaths by 2015 has led to a re-examination of wider use of DDT (dichloro-diphenyl-trichloro-ethane) in indoor residual spraying as a prevention tool in many countries. However, the use of DDT raises concerns of potential harm to the environment and human health, mainly because of the persistent and bio-accumulative nature of DDT and its potential to magnify through the food chain. This paper quantifies the adverse effects of DDT on human health based on treatment costs and indirect costs caused by illnesses and death in countries that use or are expected to re-introduce DDT in their disease vector control programs. At the global level where the total population exposed to DDT is estimated around 1.25 billion, the findings indicate that while the use of DDT can lead to a significant reduction in the estimated

Environmental Regulation and Development: A Cross-country Empirical Analysis

69 billion in 2010 U.S. dollars economic loss caused by malaria, it can also add more than

A megacity in a changing climate: the case of Kolkata

28 billion a year in costs from the resulting adverse health effects. At the country level, the results suggest that Sub-Saharan African countries with high malaria incidence rates are likely to see relatively larger net benefits from the use of DDT in malaria control. The net health benefits of reintroducing DDT in malaria control programs could be better understood by weighing the costs and benefits of DDT use based on a countrys circumstances.