Megacity Challenges: The Data
Part of Urban Sustainability and Megacities — GCSE Geography
This key facts covers Megacity Challenges: The Data within Urban Sustainability and Megacities for GCSE Geography. Revise Urban Sustainability and Megacities in Urban Issues and Challenges for GCSE Geography with 15 exam-style questions and 20 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 14 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 6 of 14
Practice
15 questions
Recall
20 flashcards
📋 Megacity Challenges: The Data
These figures apply across megacities globally and provide the specific evidence that earns marks in exam answers. Memorise the Mumbai and Dhaka case study data; use the global figures to contextualise.
| Challenge | Global Evidence | Mumbai | Dhaka |
|---|---|---|---|
| Housing shortage / informal settlements | UN: 1 billion people live in informal settlements worldwide (1 in 8 of all humans) | 55% of population in informal settlements; Dharavi: 1 million people in 2.4 km² | 40% in bastis; no piped water or sewage in most |
| Traffic congestion | Congestion costs LIC megacities 2–3% of GDP per year | Average 10 km/h | Average 7 km/h — world's worst |
| Air pollution | 7 million deaths per year globally linked to air pollution (WHO) | PM2.5 levels 5× WHO limit; 16,000 premature deaths/year | Brick kilns and traffic contribute; AQI regularly "unhealthy" |
| Solid waste | Cities globally generate 2 billion tonnes of waste/year; expected to reach 3.4 billion by 2050 | 5,000 tonnes/day; Deonar landfill regularly catches fire | 35,000 tonnes/day; no formal collection in most bastis |
| Water and sanitation | 2.2 billion people lack access to safe drinking water; 4.2 billion lack safe sanitation | Water available only a few hours/day in Dharavi | Arsenic contamination of groundwater affects millions |
| Unemployment / informal economy | 60% of urban workers in LICs work in the informal economy — no legal protections | Dharavi's informal economy worth £1 billion/year | Millions of rickshaw drivers and street vendors in informal sector |
| Flood risk | 800 million people in cities at risk from flooding by 2050 (WRI) | 2005: 944mm rain in 24 hours; 1,000+ dead | 70% of city <6m above sea level; annual monsoon flooding |