II. How do societies exploit their water resources? A. Hydraulic infrastructure – Wells (pumping underground water) – Dams (storing water) – Canals (transporting water) – Dikes (for holding water back) – Run-off ditches (for draining water)
Consumption of agricultural water by type of irrigation 2006 Water Use SystemAverage consumption M3/ha Spraying4576 Drip Irrigation3811 Gravitational (e.g. canals)6161 Irrigating all surfaces4950 Population connected to modern used water treatment plants In % of the population In % of the population Water Production through desalinization of seawater In hm3/day In hm3/day
Major Water Projects Larger and larger dams – enable irrigation – Provide electricity – Control water flow to avoid flash floods Itaipu dam between Brazil & Paraguay Dams on the Tigrus and Euphrates rivers – Water transfer Allows water to be transported for agriculture and tourism (Spain) Provides water for large urban centers located hundreds of kms from the water source (The Colorado River)
Newer Water Technology Pumping water from fossil layers Desalinization plants Used water treatment plants
B. Development of water resources modeled by societies and their environment Water resource management has shaped areas and populations – Infrastructure – collective access/management – E.g. rice fields SE Asia, rice fields demand collective effort to manage water
Rice Fields: spaces and populations dependent on water
Oasis Example – Located near water sources (underground) – Places of high population density in arid regions – E.g. Saharan Desert
Huertas Vast zones of irrigated greenhouses Prevalent in Andalousia and other areas of the Mediterranean
Consequences of Major Water Works Can lead to – complete transformation of landscape – Upsetting populations Examples – Major dams form reservoir lakes flooding large areas (3 gorges dam, China) – Forced displacement of populations – Massive draining of water supplies (e.g. irrigation) and water transfer can cause lakes & rivers to dry up (Colorado River, Aral Sea)
3 Gorges Dam
Water Map China – 3 Gorges Dam
Environmental Problems Yangtze River Case Study 3 Gorges Dam
Pollution of the Yangtze River