Dhaka Megacity

The book Dhaka Megacity: Geospatial Perspectives on Urbanisation, Environment and Health presents the use of geospatial techniques to address a number of environmental issues, including land use change, climatic variability, urban sprawl, population density modelling, flooding, environmental health, water quality, energy resources, urban growth modelling, infectious diseases and the quality of life. Although the work is focused on the Megacity of Dhaka in Bangladesh, the techniques and methods that are used to research these issues can be utilized in any other areas where rapid population growth coupled with unplanned urbanization is leading to environmental degradation. The book is useful for people working in the area of Geospatial Science, Urban Geography, Environmental Management and International Development. Since the chapters in the book cover a range of environmental issues, this book describes useful tools for assisting informed decision making, particularly in developing countries.

Flooding is one of the most devastating natural hazards in the world. Available records suggest that both flood frequency and severity are on the rise and this is likely to worsen in the context of climate change. As population, infrastructure and poverty grow rapidly in developing countries, particularly in urban agglomerations of 10 million people or more, floods could cause widespread devastation, economic damage and loss of life. Assessment of vulnerability and risk from naturally occurring phenomena is therefore imperative in order to achieve urban sustainability. This book uses geospatial techniques to evaluate hazards, risk and vulnerability at a metropolitan scale in a data-scarce country. An empirical study was performed using remote sensing, GIS and census data. This research offers a new approach to mapping population, infrastructures and communities at risk which can greatly contribute to the deeper understanding of flood disasters in a rapidly expanding megacity. Examples shown in this book are from Dhaka Megacity, however, the techniques and methods can easily be implemented in medium to large cities of similar characteristics. The book is essential reading for hazard researchers, geospatial scientists, disaster management professionals, geographers, urban planners, and social scientists. Ashraf M. Dewan is currently a Lecturer in the Department of Spatial Sciences at Curtin University, Western Australia (on leave from his substantive position as Associate Professor in the Geography & Environment Department at the University of Dhaka, Bangladesh).

This volume includes over 30 chapters, written by experts from around the world. It examines the environmental aspects of drought such as groundwater and soil contamination, river low-flow, urban water quality, and desertification. It also examines the effects of climate change and variability on drought, and discusses the differences in groundwater, rainfall, and temperatures and their related effects. It presents analytical modeling for better understanding drought in uncertain and changing climates.

Diverse driving forces, processes and actors are responsible for different trends in the development of megacities and large urban areas. Under the dynamics of global change, megacities are themselves changing: On the one hand they are prone to increasing socio-economic vulnerability due to pronounced poverty, socio-spatial and political fragmentation, sometimes with extreme forms of segregation, disparities and conflicts. On the other hand megacities offer positive potential for global transformation, e.g. minimisation of space consumption, highly effective use of resources, efficient disaster prevention and health care options – if good strategies were developed. At present in many megacities and urban areas of the developing world and the emerging economies the quality of life is eroding. Most of the megacities have grown to unprecedented size, and the pace of urbanisation has far exceeded the growth of the necessary infrastructure and services. As a result, an increasing number of urban dwellers are left without access to basic amenities like clean drinking water, fresh air and safe food. Additionally, social inequalities lead to subsequent and significant intra-urban health inequalities and unbalanced disease burdens that can trigger conflict and violence between subpopulations. The guiding idea of our book lies in a multi- and interdisciplinary approach to the complex topic of megacities and urban health that can only be adequately understood when different disciplines share their knowledge and methodological tools to work together. We hope that the book will allow readers to deepen their understanding of the complex dynamics of urban and megacity populations through the lens of public health, geographical and other research perspectives.

This book focuses on the transformation of Bangladesh in respect to its people, geography, economy and environment. The authors discuss current problems such as vulnerability caused by environmental degradation in Bangladesh but also opportunities of this rapidly changing country. The book explains how the country is rapidly transforming from a rural subsistence agrarian based economic system to a new economic partner contributing to global processes. Bangladesh is presented as an example for the changes in the Global South, where a mismatch is often observed in linking resources and activities with environmental sustainability, possibly due to insufficient base-line knowledge. As faster growth is marginalizing resources to increase the GDP, the sustainability of resource exploitation is being questioned. The authors describe the vulnerable situation caused by possible sea-level rise, soil degradation, biodiversity loss, climate extremities, urbanization, and population displacement. This volume offers comprehensive knowledge about the geography and environment of Bangladesh and aims to help readers further investigate the issues and work on solutions. The book appeals to academics, professionals and students at all levels interested in Bangladesh as well as environmental problems and geographical issues in a rapidly transforming country.

Between 1991 and 2010, Dhaka’s population more than doubled to 15 million. Simultaneously, the city’s contribution to the national economy almost trebled. Clearly, population growth was accompanied by an unmistakable trend of economic growth, and a significant decline in urban poverty and income inequality. On the other hand, Dhaka’s high population density exacerbated serious environmental challenges, and it was soon ranked as one of the world’s least livable cities. In the context of these contradictory signals of rapid urbanization, Dhaka’s Changing Landscape sets to answer three most intriguing questions: Are the poorer segments of urban population, which migrate with dreams for better lives, benefitting from positive economic trends? Are these benefits sustainable? Are these benefits creating scope for this group to have a stake in the city’s growing prosperity? By studying 600 households and applying comparative analysis over a span of 20 years, the authors examine demographic and economic trends to understand the patterns, scale, and complexity of urban poverty, income inequality, and rural–urban migration. Going beyond the space and poverty debate, they enlighten the readers about the quality of life questions, sustainability matters, and gender and generational roles and relations necessary to understand qualitative transformation and migrants’ prospects for a better future.

As urbanization continues, and even accelerates, scientists estimate that by 2015 the world will have up to 60 ‘megacities’ – urban areas with more than five million inhabitants. With the irresistible economic attractions of urban centers, particularly in developing countries, making the influx of citizens unstoppable, many of humankind’s coming social, economic and political dramas will be played out in megacities. This book shows how geographers and Earth scientists are contributing to a better understanding of megacities. The contributors analyze the impact of socio-economic and political activities on environmental change and vice versa, and identify solutions to the worst problems. They propose ways of improving the management of megacities and achieving a greater degree of sustainability in their development. The goals, of wise use of human and natural resources, risk reduction (both social and environmental) and quality of life enhancement, are agreed upon. But, as this text proves, the means of achieving these ends are varied. Hence, chapters cover an array of topics, from health management in Indian megacities, to planning in New York, to transport solutions for the chronically traffic-choked Bangkok. Authors cover the impact of climate change on megacities, as well as less tangible issues such as socio-political fragmentation in the urban areas of Rio de Janeiro. This exploration of some of the most crucial issues that we face as a species sets out research that is of the utmost importance, with the potential to contribute substantially to global justice and peace – and thereby prosperity.