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| Sunday, 22 May 2005 |
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Junior Observer |  |
| News Business Features Editorial
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The beauty of waterfalls
A waterfall is formed when water flows over a cliff or when there is a very steep drop in the river bed. There are two types of waterfalls, cataracts and cascades. Cataracts are found where there are many rapids (swift currents) in a large river. A large volume of water flows down these rapids. Cascade waterfalls have a smaller volume of water. A series of falls may form one waterfall. Waterfalls are usually found in the upper course of a river, in the hills or mountains. They form when there is a hard layer of rock covering a soft layer of rock. Water flows over the hard rock. When it reaches the soft rock, the water starts to erode or wear away the soft rock. Over thousands of years, the soft rock is eroded and the river begins to cut down vertically into the rock. This makes a cliff over which the water can topple. Over time, the cliff becomes steeper and deeper and a waterfall is formed. At the bottom of the waterfall, a plunge pool is created. Some of the water splashes onto the cliff and makes a large, hollow plunge pool by a process called undercutting. Other than their beauty, waterfalls are valuable today as sources of hydro-electric power. Waterfalls are a natural source of power. Sometimes hydro-electric power stations are built beside massive waterfalls. The water is forced to fall down long pipes to the power station below. The force of the water spins wheels which turn the turbines or engines. These turbines generate electricity, which is known as hydro-electric power. Waterfalls come in all shapes and sizes. Some are extremely tall while others are short. Some have great width while others are just chutes. They come in many different forms such as curtain, segmented, block, tiered, slide, cascade and punchbowl.
During the last Ice Age (about 10,000 years ago), the pressure of the ice in glaciers cut deep valleys into the mountains. Smaller valleys were left hanging above the larger valleys. Waterfalls are found where the smaller valleys join the larger valleys. The river flowing through the valleys has to fall many metres to join the main river below. Examples of this type of waterfall are the Multnomah Falls in Oregon and the Yosemite Falls in California (both in USA). Waterfall facts * The highest waterfall in the world is the Angel Falls in Venezuela, South America. It is 979 metres high. * Bambarakanda Ella is the highest waterfall in Sri Lanka (865 feet). It is at its peak capacity during September and October. * Diyaluma, which means 'watery light' is the second highest waterfall in Sri Lanka. * St. Claire, with a height of about 265 feet, is the widest waterfall in Sri Lanka. |
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Our Motherland is blessed with many beautiful waterfalls, which are
visited by thousands of people, every year. Some of the most famous
waterfalls in Sri Lanka are Dunhinda, Diyaluma, Bambarakanda and St.
Clairs; the list can go on. People visit waterfalls to stare at the
spectacular sight of an endless cascade of water crashing down. 
Their water discharge - the amount of water flowing over the falls - is
a characteristic that differentiates them, as well as the time of the year
they are most active.Although we don't see this in Sri Lanka, some
waterfalls are made by glaciers. 
