Rapid urbanisation in many developing countries has placed enormous pressure on urban infrastructure and services. A United Nations report examined the grow...

(a) Percentage increase in the city's population between 1995 and 2025 [2]

Population increase = 12.0 - 2.5 = 9.5 million [1]

\[ \text{Percentage increase} = \frac{9.5}{2.5} \times 100 = 380\% \] [1]

The city's population increased by 380% over the 30-year period, nearly quintupling in size.

(b) Trend in the percentage of the population living in informal settlements [1]

The percentage living in informal settlements has increased steadily from 25% in 1995 to 48% in 2025, nearly doubling over the 30-year period. This means that not only is the total population growing, but an increasing proportion of that growing population lives in unplanned, under-serviced settlements. [1]

(c) Two reasons for the rapid growth of the city's population [2]

1. Rural-to-urban migration: People move from rural areas to the city seeking better employment opportunities, higher wages, access to education, and improved healthcare services. Push factors in rural areas (poverty, land shortages, lack of services) combine with pull factors in the city to drive migration. [1]
2. Natural increase: The city's population has a young age structure (many people of reproductive age), so birth rates are substantially higher than death rates. This internal population growth compounds the growth from migration. [1]

(d) How the decline in access to clean water and sanitation could affect health [3]

1. Waterborne diseases: Lack of access to clean water forces people to use contaminated water sources (rivers, shallow wells, stagnant pools), dramatically increasing the spread of waterborne diseases such as cholera, typhoid, and dysentery. [1]
2. Sanitation-related contamination: Poor sanitation means human waste is not properly collected or treated, contaminating water sources and living areas with faecal pathogens. Open defecation and overflowing pit latrines in densely packed informal settlements spread disease-causing organisms through direct contact and via flies. [1]
3. Compounding health crisis: The combined effect of poor water and poor sanitation leads to high rates of diarrhoeal diseases, particularly among children under five, increasing infant mortality and reducing life expectancy. Malnourished children are especially vulnerable, creating a cycle of disease, malnutrition, and poverty. [1]

(e) Two strategies to improve living conditions in informal settlements [2]

1. In-situ upgrading: Upgrading infrastructure within existing informal settlements by providing piped clean water, sewage systems, and electricity connections, rather than demolishing settlements and displacing residents. This approach is more affordable and less disruptive than relocation. [1]
2. Secure land tenure: Providing secure land tenure (legal ownership or long-term leasehold) to residents of informal settlements. This gives people the confidence and legal incentive to invest in improving their own homes, because they know their investment is protected and they cannot be evicted without compensation. [1]