Water Conflicts

The Geography of Water supply Know the physical factors affecting the supply of freshwater Be aware of the growing mismatch between water supply and demand and the resulting stresses Understand how human activities affect water availability Appreciate how access to water is related to wealth and levels of economic development

Water conflicts

Where is the earth’s water?  The water cycle has two parts.  Water in stores like in the oceans and seas.  Water in transfers like flowing rivers or in the atmosphere.  Only a tiny part is moving within the water cycle at any time. Water in Stores Oceans 97% Ice Caps and Glaciers 2.3% Groundwater 0.67% Lakes and reservoirs 0.009% Water in transfers Rivers 0.02% Atmosphere 0.001%*

The Basic Water Cycle  The sun warms the ocean causing the water to evaporate.  As the warm moist air rises it cools.  The water vapour in the air condenses and turns to rain.  The rain water returns to the sea via the groundwater and rivers. *

The water cycle – more detailed

From the mountains to the river  Rain that falls will follow different routes to the river. Stored as snow Runs off the land Falls into rivers Stored in lakes Stored in trees Used in cities Stored as groundwater Soaks in from ground water*

Drainage basin terms

The Hydrological cycle Be familiar with terms inputs, outputs, flows and stores Blue water flow = water running on the surface and supplying rivers or running underground recharging aquifers. Green water flow = interception and transpiration of water by vegetation or evaporation from a variety of surfaces. Shade in your diagram and add the words to your glossary

Water Supply Linked to three main physical factors: 1. CLIMATE – distribution of water related to the earth’s climate zones eg high rainfall along the equator. Also rainfall varies with seasons eg monsoons in SE Asia 2. RIVER SYSTEMS The world’s rivers store large quantities of water and TRANSFER it across continents eg Amazon produces a high discharge and 20% of all the river water entering the ocean. River flow increases downstream as tributaries join the river

Water Supply 3. GEOLOGY Where the rock underneath is IMPERMEABLE ( will not let water pass through) water will remain on the surface as runoff creating a high drainage density ( large number of streams/ rivers). PERMEABLE rock ( will let water pass through) AQUIFERS such as chalk can store vast quantities of water underground Refer to Page 35 in text book

Water as a finite resource An issue for water supply is that the amount of water available is FINITE The oceans hold 97.5% of the global store so potentially only 2.5% is available as freshwater. Of this freshwater 80% if frozen and nearly 20% is groundwater –only 1% is easily accessible in lakes, ecosystems, atmosphere and rivers!! See graphs Page 36

Water Conflicts: the water crisis Significant areas under increasing water stress and rising water scarcity Water availability falling – long term trends Huge increases in use, especially for farming

Fears for the future

Water Stress Describe the trend In the water withdrawal In industry, agriculture and municipal ( cities) From 1900 to 2025

Scarcity and Stress Overall picture is of increasing risk of large numbers of people short of water (stress) or chronically short of water (scarcity) Reasons are physical and economic Climate change likely to make matters worse

Water Stress As population grows and demand for water increases there will be less water per person. Globally half a billion people, most living in Africa are chronically short of water. More than 1/3 of the world’s population is short of water estimated to increase to 45% by 2025

Water Stress AGRICULTURE Uses 69% of world’s water supply 17% of global area devoted to crops is irrigated Increase in use some inefficient 10x more water used for 1kg of beef compared to 1kg rice INDUSTRY Uses 21% globally increasing with BRICS HEP uses huge amounts of water but availabe for other uses once passed through terbines Caused water pollution

Water Stress Domestic 10% used in homes Varies globally eg 100,000 litres UK. 50,000 in Mali Demand doubling every 20 years WATER SOURCES Surface water – rivers lakes and reservoirs AQUIFERS – underground supplies from aquifers sole source for 25% of world population 75% of Europe’s supplies from groundwater Issues with over- abstraction and falling water tables

Pressure on water supplies WATER STRESS – annual supply per person less than 1,700 cubic metres. WATER SCARITY- annual supply per person less than 1,000 cubic metres (m3) PHYSICAL SCARCITY – more than 75% of a country or regions river flows are being used. 25% of world pop live in such areas eg USA, Australia ECONOMIC SCARCITY development of blue water flow sources limited by human and financial capacities.Over 1 billion people in Sub Saharan Africa use less than 25% of the river resources available.

Water Stress in NICs China 8% of world’s freshwater with 22% of population Water supply reach stress levels by /of Chinese cities do not have enough water all year round Irrigation used to produce 70% of food in north and Yellow river and aquifers running dry ( South North Transfer Project) INDIA 4% of world’s freshwater 16% population Demand exceed supply by industrial demand to triple 43% of precipitation never reaches rivers or aquifers 21 million wells abstract water leading to falling water table.

The water gap: Huge differences in water use across the development divide Ironically water is usually more expensive (in absolute and relative terms in the developing world/ For 1000 litres of water: Slums of Dar es Salaam $8 Municipal supply Dar es Salaam $0.34 UK tap water $1.62 USA $0.68

Widening gap: Growing Stress Climate Change Transboundary Conflict Groundwater Mining Saltwater Encroachment Diversion Pollution of Supply Increasing Economic cost Population growth

Trans-boundary water resources

Increasing conflict in hotspots See the Newsweek article by Jeffrey Sachs, 2008 The Murray / Darling basins. Salinisation of farmland, drought – area produces three-quarters of Australia's irrigated crops. Mexico City is now at serious risk of running out of clean water. 40% of the city's water is lost through leaky pipes built at the turn of the century. The Zambezi river basin in southern Africa is one of the most overused river systems in the world. Mali is dependent on the river Niger, which flows from Guinea through Mali to Nigeria. Long stretches of the river are now facing environmental catastrophe as a result of pollution. Catalonia, where authorities are pressing for the construction of a pipeline to divert water from the Rhone in France to Barcelona, plus diversion of the Ebro to the south Yellow River - All three rivers feeding China's Northern Plain are severely polluted, damaging health and limiting irrigation. The Ganges is so depleted that the Sundarban wetlands and mangrove forests of Bangladesh are seriously threatened. Between 1962 and 1994, the level of the Aral Sea fell by 16 metres. Major tensions over the River Jordan and River Litani and the aquifers under Israel and Palestine Dams building along the Euphrates and Tigris is a source of conflict in the Middle East.