Population and Environment - Case studies

High population density - Bangladesh

Geographical Factors:

• 1200 people per sq km

• Flat fertile land (Ganges Delta) supports agriculture

• Monsoon climate provides water for farming

Economic:

• Strong agricultural sector

• Rapid urbanisation and industrial growth (textiles)

• Dhaka has over 20M people (megacitiy)

Social:

• High birth rate and youth population

• Limited access to contraception

Political:

• Government policies support pop growth/urbanisation

• International migration due to job opportunities

Low population density - Libya

Geographical factors:

• 4 people per sq km

• Large Sahara desert with extreme aridity

• Harsh climate: high temperatures and low rainfall

• Limited water sources, dependent on aquifers

Economic:

• Economy based on oil and gas exports

• Limited agriculture due to poor soil and water scarcity

• Small urban centres, with most population in coastail cities like Tripoli and Benghazi

Social:

• Nomadic lifestyle in remote desert area

• Population concentrated in urban areas with better access to servuices

Political:

• History of political instability and conflict affecting pop distribution

• Migration out of Libya due to conflict

Countries experiencing malnourishment - Tanzania

Geographical factors:

• Large agricultural sector, but unpredictable rainfall affects food insecurity

• Climate change impacts crop yields through droughts and floods

• Some regions experiences desertification

Economic:

• Agriculture employs around 65% of pop but remains inefficient

• Poor rural infrastructure

• Farmers lack access to technology/fertilisers to help yields

Social:

• High levels of rural poverty limit access to nutritious foods

• Malnutrition high among children

• Urban areas have better acess to food than rural

Political

• Dependent on food aid

• Trade policies affect food prices

Crops affected by climate and soil - Rice 🌾

Climate:

• Requires high rainfall (at least 1000 mm annually)

• Grows best in temperatures between 16°C and 27°C

• Common in tropical and subtropical regions

Soils:

• Grows well in fertile alluvial soil

• Prefers clay soils that retain water, ensuring constant moisture for growth

Semi-arid Climate

• Hot summers (25°C–35°C); mild winters (10°C–20°C).

• Low rainfall (250–500 mm per year); seasonal droughts.

• Vegetation: Grasslands, scattered shrubs, drought-resistant plants.

• Prone to desertification due to overgrazing and deforestation.

Distribution:

• Found between deserts and more humid regions

• Includes parts of Africa (Sahel), Australia, USA and Central Asia

Mediterranean Climate

• Hot, dry summers (25°C–40°C); mild, wet winters (10°C–15°C).

• Rainfall mainly in winter (300–1,000 mm per year).

• Vegetation: Drought-resistant plants, olive trees, shrubs, vineyards.

• Susceptible to wildfires in summer and flash floods in winter.

Distribution:

• Located on west coasts between 30°–45° latitude.

• Found in Southern Europe, California, parts of South Africa, Chile, and Australia.

Ferrasol soils

• Found in hot, humid tropical regions (e.g., Amazon, Congo).

• Deep, highly weathered, and rich in iron & aluminium (red/yellow color).

• Nutrient-poor due to heavy rainfall causing leaching.

• Supports rainforest growth but is unsuitable for long-term farming without fertilizers.

Podsol soils

• Found in cool, temperate regions (e.g., Canada, Russia, Scandinavia).

• Acidic, with a thick layer of leached ash-grey soil beneath organic matter.

• Low fertility, lacking nutrients like nitrogen & phosphorus.

• Supports coniferous forests but requires fertilizers for agriculture

Strategies to ensure food security: Ethiopia

Challenges:

• Recurrent droughts, poor infrastructure, reliance on subsistence farming

• High population growth and land degradation

Strategies:

• Irrigation projects (small scale dams to store water)

• Improved seeds and fertilisers (from NGOs and gov. programs)

• Cimate resilient crops (e.g drought resistant maize)

• Food aid and safety nets (World Food Program)

• Diversification - encouraging off-farm employment

Top causes of death in HICs: UK, USA, Japan

• Heart disease - poor diet, lack of exercise, aging population

• Stroke - high blood pressure, lifestyle factors

• Alzheimer’s - aging population

• Diabetes - poor diet, obesity

Top causes of death in LICs: Chad, Malawi, Afghanistan

• Lower respiratory infections – Pneumonia, tuberculosis due to poor healthcare & pollution.

• HIV/AIDS – High prevalence due to lack of education, treatment access.

• Diarrheal diseases – Unsafe water, poor sanitation (e.g., cholera).

• Malaria – Mosquito-borne, common in tropical regions with stagnant water.