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Quiz yourself on Urban Sustainability and MegacitiesGet your flashcardsBuild my revision planTrack my progress⛓️ Why Megacity Challenges Are So Hard to Solve
It is not enough to list megacity challenges — examiners want to understand why they exist and why they are so persistent. The answer lies in a series of interconnected cause-chains. Each problem makes the others worse. This is called a compound urban challenge.
Population grows faster than infrastructure
Dhaka gains 300,000 residents per year. A new water treatment plant takes 5–10 years to plan, fund, and build. A metro line takes 15–20 years. The city is always a decade behind its own population. The result: more people sharing the same inadequate infrastructure, which makes every service worse even as investment increases.
Dhaka gains 300,000 residents per year. A new water treatment plant takes 5–10 years to plan, fund, and build. A metro line takes 15–20 years. The city is always a decade behind its own population. The result: more people sharing the same inadequate infrastructure, which makes every service worse even as investment increases.
Poverty limits the tax base
In Dhaka, 40% of residents live in informal settlements without legal land title. They cannot be formally taxed. The city's tax base is therefore far smaller than its population. Less tax revenue means less money for infrastructure, which means more people living without services, which means more poverty — a trap that compounds over generations.
In Dhaka, 40% of residents live in informal settlements without legal land title. They cannot be formally taxed. The city's tax base is therefore far smaller than its population. Less tax revenue means less money for infrastructure, which means more people living without services, which means more poverty — a trap that compounds over generations.
Informal settlements are hard to upgrade
In areas like Dharavi or Dhaka's bastis, land ownership is disputed, buildings are tightly packed, and infrastructure cannot be simply laid over the top of existing structures. Upgrading requires either demolition (which destroys communities) or the politically difficult task of retrofitting services into dense, legally complex areas.
In areas like Dharavi or Dhaka's bastis, land ownership is disputed, buildings are tightly packed, and infrastructure cannot be simply laid over the top of existing structures. Upgrading requires either demolition (which destroys communities) or the politically difficult task of retrofitting services into dense, legally complex areas.
Climate change amplifies existing risks
Flooding was already a problem in Dhaka and Mumbai before climate change. Rising sea levels, more intense monsoons, and more frequent extreme weather events mean that flood protection infrastructure must do ever more work — and the poorest residents, who cannot afford to live on higher ground or in better-built homes, are exposed first and worst.
Flooding was already a problem in Dhaka and Mumbai before climate change. Rising sea levels, more intense monsoons, and more frequent extreme weather events mean that flood protection infrastructure must do ever more work — and the poorest residents, who cannot afford to live on higher ground or in better-built homes, are exposed first and worst.
Result: Megacity challenges are not just big versions of small-city problems
They are qualitatively different — the scale, the speed of change, the interaction between different challenges, and the limited resources available in LICs and NEEs combine to create situations that require fundamentally different approaches from those used in wealthy, slowly-growing cities.
They are qualitatively different — the scale, the speed of change, the interaction between different challenges, and the limited resources available in LICs and NEEs combine to create situations that require fundamentally different approaches from those used in wealthy, slowly-growing cities.
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