Water conflicts content 2
water is a global commodity. population growth, economic development and rising standards of living increase the demand of water. This has consequences for well being. If the world develops some management strategies conflicts will be resolved
Terms in this set (24)
The geography of water supply
-stores and flows
The blue water flow is the visible part of the water system
The green water flow involves transpiration and interception by vegetation. These processes have important ecological and hydrological functions.
global water supplies are linked to three things climate, river and geology
How does climate affect water supply?
The distribution of water is related to the earth's climatic zones. Some regions receive high amounts of rain such as regions around the equator such as the amazon. Some regions receive lots of rain such as monsoon . areas with mountains have vast water reserves,
How do river systems affect the water supply?
The worlds major rivers contain a lot of water. The amazon has a discharge of 219,000 cumecs and a catchment area of 6,915,000 km^2. This is 20% of all the water entering the worlds oceans. river flow increases downstream and tributaries feed into the river. High temperatures lead to water loss by evaporation.
How do water supplies affect the geology of a river?
The rocks underlying basin is impermeable. water will remain on the surface as runoff and high drainage density. Permeable soils and rocks such as chalk and porous limestone.
How much water on this earth is actually fresh water and useful for human use ?
what is water stress and what causes it?
The high increase in population and less units of water per person. for rich countries a decrease in water may not be a problem but for half a billion people it could be life threatening. All continents face water shortages. over 1/3 of the world lack water. 45% of the world will lack water by 2025. FAO expects water demand to rise to 5235 km^3. There is rising demand for agriculture, industry and domestic uses.
Water usage in agriculture?
Agriculture uses a lot of water and we struggle to increase food supplies for the global population. agriculture consumes 69% of 4,430.7 km ^3 a year for fresh water supply. 1kj of beef is more water costly than rice. at present 17% of the area of growing crops is irrigated. Even though water increases food water is used inefficiently and it is done through poor management of water systems, problems with evaporation, seepage, salinisation and water and fertiliser pollution.
water usage in the industry ?
water used in the industry rose to 21% . water usage in the industry has grown rapidly especially in countries that are well developed.
Water usage in domestic usage.
this varies from country to country. More economically developed countries have 100000 litres per person per year and in lower economic countries it is around 50 000 litres a year. global domestic demand is doubling every 20 years.
Where does water come from?
our water sources come from two areas Surface water resources such as rivers lakes dams and reservoirs. Construction of dams leads to short term supply of of hydroelectric power and flood control. But these must be measured in longer term environmental and social impacts.
Aquifers - there has been large scale over abstraction of water in these areas.
Pressure on the water supplies?
There is a mismatch between water supply and water demand. Water stress is the term used for the annual supply of water per person below 1700m^3. when this falls to 100m^3 the term used is water scarcity.
Physical scarcity occurs when 75% of the country or region flows are being used.
-economic scarcity this is where blue water flow is limited by human and financial captives. In areas such as sub saharan africa.
How does economic growth affect? Indian case study
india has 4% of the worlds water but 16% of the population.demand will exceed supply in 2020. water demand doubles and industrial demand triples.43% of the precipitation never reaches the rivers or aquifers. and water tables are falling rapidly as far as 21 million.
How does economic growth affect? China case study
China has 8% of the worlds water but 22% of the worlds population. 2/3 of the worlds population do not have enough water. The yellow river is highly polluted.
The beijing tianjin regions
Beijing china's capital will soon run out of water. the demand and supply gap will widen, the wells will dry up and river systems will become polluted.
What are the causes?
The beijing region is prone to floods and droughts. Most precipitation falls in july and september. there are several wet years followed by several dry years. the population of 16 million makes it higher than shanghai. Tianjin is major heavy industry, commerce developing services. Beijing's population growth is 2.5% as urban to rural migrants continue to arrive.
Beijing draws 60% of it's water from aquifers. in the 90's a series of droughts happened. These lowered the water table in some areas as much as 40 million. Tianjin relies on 30% of it's groundwater supplies. upstream withdrawals and contamination of the water has been detrimental.
The demand of water?
water deman in the beijin tianjin region is well above 4 million m^3. agriculture and industry have increased this demand.
Human impacts on water availability
Human activity has a negative impact on the environment.
pollution is caused by human activity and excessive abstraction of water. sewage disposals in developing countries cause 135million deaths according to WHO, In the Uk we add 1400 litres of sewage daily to our river systems. Chemical fertilisers contaminate the ground water and water supplies. Each 400 billion tonnes of industrial waste. Big dams trap the sediment in the reservoirs.
Removing water from rivers and groundwater sources. drinking water for irrigation. Worldwide water is being extracted from the aquifers than is replaced.the removal of the water has upset the natural balance of saline and fresh water lead to salt water incursion and salinisation of wells , boreholes and wetlands.
Access to water
Water insecurity means not having enough water despite efforts to improve sanitation. 1.2 billion have no access to clean water. In water insecure countries few opportunities to escape the poverty and access to benefit the economy.
Poverty and water
water is described as being the lubricant of development. Improved water supply improves sanitation and production bringing better health.
The price of water
demand overtakes supply in the global market. water costs will eventually become as high as oil. in washington DC people pay $350 for water. in rural areas water is usually free but people have to travel long distances.
the price of water?
californian cities import water over milers from the colorado basin
- lifting and pumping water is energy and economic expensive.
-water in australia peaked by 75 cents
- some farmers have to abstract water instead of irrigating their farmland.
-Water subsidies can be large in the city of delhi this makes up to 80%.