ABSTRACT
Urbanization is a process of modern development phenomenon in the world context. The hybrid of natural and manmade elements whose interactions are affected not only the environment but also the cultural environment, as well as by heritage, architecture, human behavior, politics, economics, and social organizations. Urban areas cannot exist in isolation of this process. The urbanization growth rate is very high in developing and develop countries. The ecological footprint of urban areas has shown that a city requires productive land, but several times the size and shape of a city have changed the supporting services for citizens. Drought is a new threat for the urban inhabitants in Asia, Africa and Latin American large cities. Dhaka city has emerged as a fast-growing megacity in recent times, and Rajshahi is becoming an emerging megacity. Dhaka is nevertheless one of the more balanced ones due to its friendly ecological footprint. It began with a manageable population of 2.2 million in 1975, which reached 12.3 million in 2000. The population is about 18 million in 2015. The estimated urban population would be 22.8 million in 2025, and it would hold the rank of being one of Asia’s megacities. The urban population growth rate is 6.9% in Bangladesh. Dhaka city has found its highest rate of physical and population growth during 1981–1991, with the 18population doubling during that decade and the city expanding from 510 to 1353 km2. However, the expansion of Dhaka city is constrained by physical barriers such as the low-lying flood-prone areas around the city and recent drought and environmental pollution, which to be specific conditions in spatial prevention. Global warming and drought hazards are the critical barriers of urban expansion and agglomeration in general. Dhaka and Rajshahi cities are also facing similar barriers in Bangladesh. The urban ecosystem services of Dhaka and Rajshahi cities has been degraded due to drought, rapid growth of population and city size expansion, infrastructure development, shrinking of fluvial process, drinking water scarcity, reduction of vegetation and green spaces, vehicle and air pollution, increased industrial pollution, slum development, and waste mismanagement. The megacities’ ecosystem service development planning is essential for the betterment of Asia’s largest megacities’ social life. The urban ecosystem services and their potential value is one of the combined targets in the responsibility for a better ecological footprint, life, and health quality as well as cultural, social, and certainly socioeconomic improvements in city development and planning necessary to ensure prevention of annual urban drought and hazards.
