Confined Aquifer

An aquifer is a layer of soft rock, like limestone or sandstone, that absorbs water from an inlet path. Porous stone is confined between impermeable rocks or clay. This keeps the pressure high, so when the water finds an outlet,it overcomes gravity and goes up instead of down without the need for pumping. In this case is the presence of an artesian well.
The Great Artesian Basin is the largest and deepest artesian basin in the world, occupying 23% of the Australian continent.

Great Artesian Basin

Suez Canal

Sometimes what appears to be impermeable, can suddenly become permeable. The opening of the Suez Canal in 1869 created the first salt-water passage between the Mediterranean and Red seas. It allows water transportation between Europe and Asia without navigating around Africa, through an artificial sea-level waterway in Egypt. It contains no locks: seawater flows freely through the canal. In general, the Canal north of the Bitter Lakes flows north in winter and south in summer.

Air view of whole Suez canal

@ Look at Suez Canal Company stamps

三峡大坝 / Three Gorges Dam

世界第一大的水电工程，位于西陵峡中段的湖北省宜昌市境内的三斗坪，距下游葛洲坝水利枢纽工程38公里。三峡大坝工程包括主体建筑物工程及导流工程两部分，工程总投资为954.6亿元人民币。于1994年12月14日正式动工修建，2006年5月20日全线建成。2010年7月19日，三峡大坝将迎来一次峰值在65000立方米/秒左右的洪水。堪比1998年长江三峡河段的最高峰值，这也将是三峡水库建成以来所面临的规模最大的一次洪水挑战。


@B About the porosity of dams
@ 看看整个故事 / Look at the whole story