Urban Issues and ChallengesDefinitions
Key Terms
Part of Urban Sustainability and Megacities — GCSE Geography
This definitions covers Key Terms 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 9 of 14 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 9 of 14
Practice
15 questions
Recall
20 flashcards
📖 Key Terms
- Megacity
- A city with a population of more than 10 million people. In 1950, there were 2 megacities (New York and Tokyo). By 2024, there were 37. Approximately 90% of current megacity growth is in LICs and NEEs in Africa and Asia.
- Rural-urban migration
- The movement of people from rural (countryside) areas to urban (city) areas. This is the primary driver of megacity growth in LICs and NEEs. It is explained by the push-pull model: push factors drive people from rural areas; pull factors attract them to cities.
- Push factor
- Something that encourages or forces people to leave their current location. In the context of rural-urban migration to megacities, push factors include: mechanisation of farming (fewer agricultural jobs), natural disasters (floods, droughts), lack of rural services (schools, hospitals), and conflict.
- Pull factor
- Something that attracts people to a new location. Pull factors drawing migrants to megacities include: higher wages (urban workers earn 3–5× more than rural workers), better services (schools, hospitals, electricity), more diverse employment opportunities, and social networks of family or friends already in the city.
- Informal settlement
- A residential area built without legal permission, usually without access to piped water, sewage, formal waste collection, or secure land tenure. Also called slums, shanty towns, or — in India — bastis. Informal settlements house approximately 1 billion people globally (UN estimate). They are NOT simply places of poverty — many, like Dharavi in Mumbai, have sophisticated local economies.
- Top-down development
- Development planned, funded, and implemented by governments or large organisations (e.g. the World Bank, ADB) from above, without necessarily involving the communities affected. Examples: Mumbai Metro, ADB flood embankments in Dhaka, Singapore's Certificate of Entitlement system.
- Bottom-up development
- Development planned and led by communities themselves, often through NGOs, local organisations, or informal self-help. Examples: BRAC microfinance in Dhaka, Dharavi's self-organised recycling industry, Favela-Bairro in Rio de Janeiro.
- Urbanisation
- The increasing proportion of a country's population living in urban areas. Global urbanisation has been one of the defining demographic trends of the 20th and 21st centuries. In 2007, for the first time in human history, more than half of the world's population lived in cities.
- NEE (Newly Emerging Economy)
- A country experiencing rapid economic growth, moving from being a Low Income Country (LIC) towards High Income Country (HIC) status. Examples: India, China, Brazil, South Africa, Nigeria. NEEs often have megacities growing faster than their infrastructure can keep pace.