Informal Development in Gulshan, Dhaka by Aditya Kabir via Wikimedia Commons
The urban landscape of Bangladesh’s capital Dhaka is transforming. Since the megacity has a population of 22.5 million and the world’s highest population density, each change has a critical effect.
Between the bustling city of Dhaka and greater Bangladesh’s rural landscapes lie transitional buffer regions. These are called “peri-urban” spaces and are an intermediate between urban and rural environments. Fragmented, disjointed, yet rapid development characterizes these regions. Peri-urban spaces incrementally expand cities’ boundaries as this land is used to house the growing population.
These new residential spaces in Dhaka typically consist of informal housing settlements, streetside vendors, and other infrastructure which fall outside government regulation. That leaves residents highly vulnerable to clean water insecurity, flooding, and resulting climate migration.
Peri-urban spaces are drawing a growing number of Bangladesh’s rural climate change refugees. Dhaka receives 400,000 climate refugees per year – the majority of whom live in informal housing settlements.
Golam Mortoja and Tan Yigitcanlar, researchers from the Queensland University of Technology, have used spatial analysis techniques to map how Dhaka’s rapidly growing peri-urban spaces are becoming increasingly vulnerable to natural hazards such as flooding. They also examine how peri-urbanisation is contributing to climate change.
Residents Take to the Hills
The study found that sub-districts of Dhaka on higher elevations have larger residential populations. People move to high ground to avoid floods during the monsoon season — a significant threat in Dhaka, where a quarter of the city is highly exposed to monsoon flooding.
Gazipur Sadar is a high-elevation district in northern Dhaka facing rapid peri-urbanisation. In the past two decades, Gazipur Sadar’s population has grown faster than any other part of Dhaka. The researchers found that population growth drove a significant transition to a peri-urban environment.
Map from Mortoja and Yigitcanlar’s “How does Peri-Urbanisation Trigger Climate Change Vulnerabilities?”
The map above shows Dhaka’s changing landscape from 1992 (Chart a) to 2016 (Chart b). Gazipur Sadar, located in the north, became largely peri-urban due to a significant decrease in rural landscapes and a fluctuating urban environment.
This research reveals a surprising shift. Some urban areas in Gazipur Sadar have transitioned into peri-urban spaces. How did this happen?
The research shows how new zoning policies drew the garment industry to Gazipur Sadar and with it, an influx of workers in need of immediate housing. It also found that 70% of informal housing settlements in Dhaka exist on privately owned land. The need for housing and neglect of privately-owned land in Gazipur Sadar has contributed to the development of informal housing settlements in the sub-district and its shift from urban to peri-urban.
Normally, peri-urban spaces become urban. The shift from urban to peri-urban environments reveals a grave failure in governmental residential regulation, affordable housing availability, and urban planning.
The expanding peri-urban areas make previously ‘flood-safe’ regions of Dhaka more susceptible to natural disasters. Informal development projects typically lack adequate water supply, sanitation, sewerage, drainage, and electricity. The lack of these basic facilities results in pollution from improper waste disposal, fire hazards from outdoor cooking, and other methods to fulfill the functions of these necessities. This pollution can potentially cause landslides, flooding, and natural hazards.
The Future of Peri-Urbanisation
The researchers caution that peri-urbanisation cannot be allowed to continue in Dhaka. Current peri-urbanisation puts flood-safe regions at risk. Further urban expansion would take place in flood-prone areas.
The study makes clear that policymakers must closely monitor and regulate peri-urbanization. This development may result in safe and environmentally sustainable urban environments. Policymakers may also encourage the development of rural environments that would offer financial and residential security for Dhaka’s residents.
The need for action is urgent. Bangladesh will have an estimated 13 million climate migrants in the next 30 years. Today, research shows that 68% of the country’s climate migrants move to Dhaka. Without area-specific management of peri-urban spaces to accommodate vulnerable communities, Dhaka’s landscape and its communities are in grave peril.