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This lesson examines the specific causes of water insecurity in greater depth, using detailed case studies of the Aral Sea, the River Nile, the Mekong River and the Colorado River. It addresses Edexcel A-Level Geography (9GE0) Paper 1, Topic 5, Enquiry Question 3: How does water insecurity occur and why is it becoming such a global issue?
Water insecurity arises from the interaction of physical, economic, social and political factors. These causes are often interlinked and mutually reinforcing.
| Category | Causes |
|---|---|
| Physical/environmental | Climate variability, arid climate, unreliable rainfall, droughts, groundwater depletion, contamination, salinisation |
| Demographic | Population growth, urbanisation, rising per-capita consumption |
| Economic | Poverty, under-investment in infrastructure, inefficient irrigation, industrial pollution |
| Political/governance | Corruption, transboundary disputes, lack of regulation, inequitable allocation, conflict |
| Technological | Lack of water treatment, aging infrastructure, leakage, absence of metering |
The Aral Sea disaster is the most dramatic example of human-caused water insecurity in modern history — an environmental catastrophe driven by agricultural policy decisions.
From the 1960s, the Soviet government diverted water from the Amu Darya and Syr Darya to irrigate vast cotton plantations in Uzbekistan and Turkmenistan. The Karakum Canal (1,375 km long, one of the largest irrigation canals in the world) was a major driver.
| Factor | Detail |
|---|---|
| Irrigation diversion | By 1990, 90% of the Amu Darya and Syr Darya flow was diverted for irrigation before reaching the Aral Sea |
| Inefficient irrigation | Flood irrigation methods wasted 50–70% of diverted water (evaporation, seepage, waterlogging) |
| Cotton monoculture | Uzbekistan became the world's 5th largest cotton producer; cotton is extremely water-intensive (~10,000 litres/kg) |
| Soviet central planning | Decisions made in Moscow prioritised production quotas over environmental sustainability; local populations had no say |
| Lack of environmental assessment | No consideration of downstream impacts; the sea's destruction was considered an acceptable cost of cotton production |
| Category | Impact |
|---|---|
| Shrinkage | Surface area shrank from 68,000 km² (1960) to ~8,300 km² (2020) — an 88% reduction; volume decreased by ~90% |
| Salinity | Salinity increased from ~10 g/L (1960) to >100 g/L (South Aral, 2010) — more than 3× ocean salinity |
| Biodiversity | All 24 native fish species became extinct in the South Aral; waterfowl populations collapsed |
| Fishing industry | 40,000+ jobs lost; the port of Muynak is now 150 km from the water's edge |
| Health | Exposed seabed covered in salt and pesticide residues (from cotton farming); dust storms carry toxic particles; respiratory diseases, kidney failure and cancer rates dramatically elevated in surrounding populations |
| Climate | Loss of moderating effect; region now experiences hotter summers (+2–3°C) and colder winters (−2–3°C); reduced rainfall |
| Desertification | 54,000 km² of former seabed now exposed — the Aralkum Desert, one of the world's newest deserts |
Exam Tip: The Aral Sea is a powerful case study of human-caused water insecurity. It demonstrates the interconnection between water management decisions, agricultural policy, environmental degradation and health impacts. Always link causes to consequences systematically.
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