Changes

Riverbed infiltration galleries

6 bytes added, 02:29, 9 November 2012
Construction, operations and maintenance
Since the trees below must have their tap root in the water table, the depth of a water-table can be found by knowing the depth of the tree’s tap root. A rule of thumb states that the tap root of a tree has a depth equal to about 3⁄4 of the height of the tree. The height of a tree can be found by measuring the length of the shadow the tree is casting on the ground and comparing it with the length of the shadow of a stick 100 centimeters long. The two measurements should be taken in the sunshine of early morning or late afternoon when the shadows are longest. For example: If the stick’ shadow is 80 cm long, the ratio is: 80/100 = 0.8. If the tree’s shadow is 12 m long, then the tree is: 12 m x 5 / 4 = 15 m high and the tap root and water level is at: 15 m x 3⁄4 = 11.25 m depth.
[[File:WaterTableDepthChart.jpg|thumb|center|400px|Vegetation that tells you about how deep the water is beneath it. Click on chart to zoom in.]]
====Other considerations====
Akvopedia-spade, akvouser, bureaucrat, emailconfirmed, staff, susana-working-group-1, susana-working-group-10, susana-working-group-11, susana-working-group-12, susana-working-group-2, susana-working-group-3, susana-working-group-4, susana-working-group-5, susana-working-group-6, susana-working-group-7, susana-working-group-8, susana-working-group-9, susana-working-group-susana-member, administrator, widget editor
30,949
edits