Showing posts with label LATEST NEWS. Show all posts
Showing posts with label LATEST NEWS. Show all posts

Tuesday, April 26, 2011

There’s a Giant Hole in this Dam Water! [Bell-Mouth Spillways]


morning-glory-plughole-spillway
At first glance you might mistake a bell-mouth spillway for a watery vortex into another dimension. What can only be described as a giant hole in the water is actually a method for controlling the release of flows from a dam or levee into a downstream area. These spillways help prevent floods from ‘dam’-aging or destroying a dam.
vortex-in-the-water-monticello-dam
glory-hole-in-water-ladybower-dam
Photograph by The Cat’s Place


SPILLWAYS
- A spillway is a structure used to provide for the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed
- Spillways release floods so that the water does not overtop and damage or even destroy the dam. Except during flood periods, water does not normally flow over a spillway
- In contrast, an intake is a structure used to release water on a regular basis for water supply, hydroelectricity generation, etc.
- Floodgates and fuse plugs may be designed into spillways to regulate water flow and dam height
- Other uses of the term “spillway” include bypasses of dams or outlets of a channels used during highwater, and outlet channels carved through natural dams such as moraines
Source: Wikipedia
giant-dam-spillway-ladybower-resevoir
Photograph by Jon Bradbury
bell-mouth-spillway1
Photograph by Traqopodaros


BELL-MOUTH SPILLWAYS
- Some spillways are designed like an inverted bell so that water can enter all around the perimeter. These uncontrolled spillway devices are also called: morning glory, plughole, glory hole, or bell-mouth spillways
- In areas where the surface of the reservoir may freeze, bell-mouth spillways are normally fitted with ice-breaking arrangements to prevent the spillway from becoming ice-bound
Source: Wikipedia
glory-hole-spillway
Photograph by David Wilby
hole-in-the-water-ladybower
Photograph by Buster Bakewell


LADYBOWER RESEVOIR
- The images above are from the spillways located at the Ladybower Resevoir
- The Ladybower Reservoir is a large Y-shaped reservoir, the lowest of three in the Upper Derwent Valley in Derbyshire, England
- The River Ashop flows into the reservoir from the west; the River Derwent flows south, initially through Howden Reservoir, then Derwent Reservoir, and finally through Ladybower Reservoir
- Its longest dimension is just over 3 miles (5km), and at the time of construction it was the largest reservoir in Britain (1943)
Source: Wikipedia
giant-plughole-monticello-dam
Photograph by the U.S. Bureau of Reclamation
monticello-dam-aerial
Photograph by the U.S. Bureau of Reclamation


MONTICELLO DAM
- The Monticello Dam is a dam in Napa County, California, United States constructed between 1953 and 1957
- It is a medium concrete-arch dam with a structural height of 304 ft (93 m) and a crest length of 1,023 ft (312 m)
- It contains 326,000 cubic yards (249,000 m³) of concrete. The dam impounded Putah Creek to cover the former town of Monticello and flood Berryessa Valley to create Lake Berryessa, the second-largest lake in California
- The capacity of the reservoir is 1,602,000 acre•ft (1,976,000 dam³). Water from the reservoir is supplied mostly to the North Bay area of San Francisco
- The dam is noted for its classic, uncontrolled spillway with a rate of 48,400 cubic feet per second (1370 m³/s) and a diameter at the lip of 72 ft (22 m).
Source: Wikipedia
massive-hole-in-the-water
Photograph by the U.S. Bureau of Reclamation
monticello-damn-giant-spillway
Photograph by the U.S. Bureau of Reclamation




large-hole-in-the-water
Photograph by Keartona
bell-mouth-spillway
Photograph by Ian Stuart Armstrong
large-bell-mouth-spillway-monticello-dam
Photograph by Spider Bob
plug-hole-giant-drain-in-water
Photograph by Carl McCabe
ladybower-plughole
Photograph by ChezyNickAnnie
water-outlet-ladybower-resevoir
Photograph by Wedesoft
big-hole-in-the-water
Photograph by Martin Roberts
morning-glory-hole-in-the-water
Photograph by Preseverando

SOURCES
- Wikipedia: Spillways
- Wikipedia: Ladybower Resevoir
- Wikipedia: Monticello Dam

Japan Before and After Earthquake and Tsunami

Photos from the GeoEye satellite imaging company from before and after the March 11 earthquake and tsunami in Japan show sobering views from above of the disaster.


Village wiped out near Fukushima nuclear power plant

Before


After


Fukushima II nuclear power plant

Before


After


South of Fukushima nuclear plant

Before


After


Iwaki beach

Before


After


Ueda in Iwaki, Samegawa river outlet

Before


After


South coast of Kesennuma

Before


After


Minamisanriku

Before


After


Soccer field in Minamisanriku

Before


After


Coastline near Minamisoma

Before


After


Rikuzentakata

Before


After


Sendai Airport

Before


After


Arahama in Sendai

Before


After


Fujitsuka in Sendai

Before


After


Yuriage in Natori

Before


After


Yuriage in Natori (looking west)

Before


After


Kashimaku in Minamisoma

Before


After


Haranomachi in Minamisoma

Before


After


Yagawahama in Miyagi (Oshika Peninsula)

Before