Urban systems and urban planning

The process by which an increasing proportion of a population lives in urban areas (cities and towns).

An increasing proportion of people living in urban areas over time.

Housing shortages (slums), infrastructure strain (water/sanitation/transport), and increased pollution (air/water/solid waste).

Greater efficiency in services, better access to healthcare/education, and hubs for innovation and economic growth.

Rural-to-urban migration and natural increase in urban populations (also reclassification and economic development).

Push: lack of jobs, poor services. Pull: employment, better healthcare/education.

A factor that drives people to leave rural areas (e.g., lack of jobs, poor services, land degradation).

Dense populations can share infrastructure, reduce per-capita travel, and lower resource use per person if planning and services are effective.

Housing shortages, pollution, and infrastructure overload (water/sanitation/transport).

A factor that attracts people to cities (e.g., jobs, higher wages, better services).

More efficient service delivery, economic growth/innovation, and improved access to healthcare and education.

Housing built without legal land tenure and often lacking basic services such as clean water, sanitation, and electricity.

Show balance: explain both challenges and opportunities, then evaluate solutions and trade-offs.

Because growing settlements can be redefined from rural to urban, changing the statistics.

State the trend, quantify change with numbers, and compare regions/countries if shown.

Uncontrolled expansion of urban areas into rural land, typically low-density and car-dependent.

The CBD (Central Business District).

The commercial and business centre of a city with the highest land values and tallest buildings.

CBD, residential zones, and industrial zones (also green spaces and transport infrastructure).

Low-density housing and car-dependent layouts with separated land uses.

Habitat loss, higher transport emissions from longer commutes, and increased runoff due to more impervious surfaces.

Habitat loss and increased greenhouse gas emissions from longer commutes.

An area that combines residential, commercial, and sometimes light industrial uses, reducing travel needs.

Land uses are spread out and separated, making walking and public transport less practical.

Higher household transport costs and social isolation (also inequality and high infrastructure costs).

Concentric zone model: CBD at the centre with rings of land uses around it (alternatively sector or multiple nuclei).

The multiple nuclei model (Harris and Ullman).

Compact, mixed-use development with good public transport (transit-oriented development).

Large buildings/warehouses with open yards, often near rail, highways, ports, or major transport links.

Use visual clues: tall dense buildings (CBD), uniform housing (residential), large warehouses (industrial), vegetation (green space).

Dense, mixed-use development concentrated around public transport hubs to reduce car use.

Designing and managing cities to meet present needs while protecting the environment and quality of life for future generations.

Environment (green spaces), Economy (jobs and viable transport), Equity (affordable housing and access to services).

A protected ring of countryside around a city that limits outward expansion and reduces sprawl.

Urban sprawl and car dependency (by increasing density and walkability).

Reduced car dependency and lower per-capita emissions due to shorter travel distances.

Bus rapid transit/metro systems and safe cycling infrastructure (bike lanes, bike sharing).

Natural or semi-natural features such as parks, trees, green roofs, and permeable surfaces that provide ecosystem services.

Permeable surfaces and sustainable drainage systems (SUDS) such as retention ponds or swales.

They show real-world application and improve evaluation (e.g., Curitiba for BRT, Copenhagen for cycling, Singapore for water).

Environment, Economy, and Equity.

High upfront costs, political resistance, and equity issues (who benefits and who pays).

Compare multiple approaches and judge them using effectiveness, cost, equity, feasibility, and co-benefits.

A city is not truly sustainable if benefits and burdens are unfairly distributed or if poorer groups are displaced or excluded.

A purpose-built city designed to minimise environmental impact (energy, transport, waste, water) while supporting quality of life.