Geography - The water cycle case studies

The three Gorges Dam

- designed to control flooding on the Yangtze, improve water spooky by regulating river flow and generate HEP.

impacts:

- 632km squared of land flooded to form the reservoir

- 1.3 million people relocated from 1500 villages

- low water quality due to waste from industry sewage and farms

South-North Water Transfer Project

- Beijing has 35% of chinas population and 40% of its arable land but only 7% of its water

- 3 routes will take water from the Yangtze to the North

impacts:

- cost US$70 Billion

- will submerge 370km squared of land

- 345,000 people will have the relocate

- risks draining too much from south

pros:

- reduce risk of water shortage in Beijing and boost economic development

- will reduce the abstraction of groundwater

Israels Desalination project

- provide reliable and predictable supply of water.

- aims to provide 70% of domestic water supply by 2020

impacts:

- each plant requires its own power station and adds up to CO2 emissions

- produces vast amounts of salt containing agents that harm ecosystems

pros:

- produces up to 600 tonnes of potable water per hour

Turkey, Syria and Iraq

- potential for conflict as GAP project in Turkey involves damming the Euphrates and Tigris rivers in Syria and Iraq.

Aims of GAP project:

- construct 22 dams, 19 HEP plants and 2 water transfer tunnels

- provides irrigation for 1.7 million hectares

- diversify agriculture into cash crops

- Help Turkish economy grow by 12%

The Sahel

- climate is changing so opportunity for re-greening. This involves planting trees and bushes alongside other sustainable management schemes.

pros of re-greening:

- low cost reforesting

- natural regeneration of water-retaining shrubs and trees

California

- over 40 million Californians facing problems due to variations in rainfall.

- in 2014, Sierra Nevada region experienced three times the normal number of wildfires.

- intense mega-droughts forecasted over next 30 years.

- 2015 drought - worse one in 1200 years, water rationing imposed

- 90% chance of decade long drought.

causes:

- increased evaporation rates

- fall in precipitation

problems already seen:

- surface runoff + soil moisture levels have declined

- groundwater levels fell by 30m between 2011 and 2015

- reservoir levels fallen.

2014-2015 Rio drought

causes:

- high pressure systems diverted rain-bearing winds further north

impacts:

- water rationing for 4 million people

- water supplies cut off for 3 days a week in some towns

- halting of HEP production , more power cuts

- depletion of 17 largest reservoirs ti dangerously low levels

- increased groundwater abstraction