Littered water

Unprotected stream

Dirtied water

Interdependent creatures

Like the flowing river

River restoration, need of the hour :

Priyanka Kurugala

Natural features such as rivers, waterfalls, marshy lands and wetlands are important places where water plays an important role in terms of biology, ecology and water chemistry.

Streams badly need restoration. Pictures by Dr Wasantha S Weliange

Maintaining such habitats in a natural way is important for the well being of human beings. Present day tourism is based on observing and enjoying nature to improve the intellectual well being of the man. Therefore conserving and maintaining watery habitats is a must for a country. The culture, heritage and economics are strongly bound with it. On the other hand tourism is basically dependent on beauty and freshness of the landscape of a country. Therefore protection and conservation of nature has a direct relationship to the economy of a country.

Dr Wasantha S Weliange of the Kelaniya University researches about how rivers function in Sri Lanka. He points out following steps to improve water habitats in Sri Lanka; particularly in Colombo. One of the four major rivers, Kelani flows to the sea from Colombo across Western Province in Sri Lanka. Diyawanna stream which runs closer to the Parliament is a tribute to the Kelani River and has subjected to legendary poems such as Selalihini Sandesa. Other than these two rivers, there are numerous canals built during the Dutch period for transportation. It is pathetic to notice that nobody needs to mediate or take real action to safeguard these important habitats to improve the well being of humans and the beauty of nature.

Although during the past those Dutch canals were used for transportation of goods presently they are just canals which transport garbage and sewerage. Many industries directly discharge their polluted industrial effluents into water resources while others discharge all sort of unwanted materials into canals. This leads to foul smells and inappropriate scenes.

Water is more important as a natural resource than fresh air. Water running in these canals is not fit to any important things, or for survival of animals and plants that benefit man or ecosystem but bacteria, worms and pathogens can cause severe diseases to man and other animals. Completely black and turbid water carry oils, paints and many other industrial wastes to sea though these canals. The slow flow through the canal increases the ground water pollution and the polluted water seeps through the earth.

Heavy metals and non-degradable chemicals dissolve into the groundwater and pollute making it unsuitable for human use. Slowly flowing water provides the best conditions and habitats for mosquitoes and other blood-sucking insects to increase their population. On the other hand canal banks are made of large cobbles which provide spaces for rats and cockroaches to live. The beauty of flowing water no longer could be seen as beautiful, but something that carries dirt, sewerage, solid wastes and water plants such as Icornia species. About 30 years ago most rivers and waterways faced the same situation in many other western countries. Nevertheless they were able to restore rivers and bring back the life to those streams.

The flowing water has lots of life. Dr Welianga has found out that in one square metre in the river bottom, there are around 4000 young stages of insects that belong to mayflies, stoneflies, beetles, caddis and dragon flies living. All those creatures carry out an important task for keeping the river healthy. They eat dirt or any organic waste coming to the water. They also help control the menace of insects such as mosquitoes and blood sucking creatures such as biting midges.

Those insects living in the river bottom become food for fish while they grow in the water. Once becoming adults they come out from the water’s surface and become food for birds and bats. Destruction and construction are both a possible act. River restoration, therefore, should be given prominence.

River restoration

River restoration is the act of working with a degraded river or stream in order to return it to a pre-disturbed condition. A disturbance is anything that disrupts a stream and knocks it out of equilibrium. Common disturbances in Lancaster County result from suburban sprawl and agriculture. These land use practices cause excess sediment, nutrients, and chemicals to run into the water. Restoration projects work on different scales. A reach is a small section of a stream, while a corridor is the entire length of the stream.

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Watersheds

A watershed is an area of land that contributes water to a common network of streams. Watershed boundaries or ‘divides’ occur along high points in the landscape that separate different stream networks. Large watersheds are composed of many smaller watersheds upstream of the primary river in the network. All streams in the Little Conestoga watershed flow into the Conestoga River, then into the Susquehanna River which flows into the Chesapeake Bay. Each stream or river in the watershed is called a tributary of the larger river downstream.

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Types of Restoration

There are many components to stream restoration. Most common efforts focus on stream bank stabilization, enhancing riparian buffers by adding trees and natural grasses, the removal of dams and other man-made structures, adding meanders, and stocking the river with fish or other living organisms.

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Streambank Stabilization

Basic streambank stabilization may involve placing large cobbles or boulders along banks and replanting native vegetation. More sophisticated stabilization procedures include ‘vegetated geogrids,’ where alternating layers of live branches, called fascines, are buried along the stream bank.

These can be installed along with ‘live stake’ cuttings inserted upright into the soil. Banks can further be stabilized using ‘biologs’ (bundles of coconut fibers) placed at the bottom of a stream bank to hold the bank in place. ‘Rootwads’ are uprooted trees installed into the stream bank with the roots facing into the channel. These structures encourage different speeds of water flow where different organisms can live. They also serve to trap sediment, stop erosion, and prevent damaging effects from pollution.

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Riparian Buffers

Planting trees and grasses creates a ‘green sponge’ that filters water flowing into the stream and traps excess sediment. Sediment is problematic because it blocks light to underwater vegetation and lowers the water oxygen levels that fish and other organisms need to survive. These sponges are called riparian buffers. Riparian buffers are planted next to streams and are ideally 20 to 30 feet wide on either side of the river.

Small dams and other structures were put into place around Lancaster to power mills. However, most dams are unnecessary today. Dams harm streams by blocking fish from their native spawning grounds.

www.littleconestoga.org

Genghis Khan the green

Chamari Senanayake

Recently, a study held by Carnegie Institution’s department of Ecology measured the carbon impact of a number of historical events that involved a large number of human deaths.

In outer Mongolia in temperatures of minus 30 degrees these photographs of the legendary horses descended from the beasts that Genghis Khan’s men rode in the 13th century has been taken. www.bnps.co.uk

Time periods looked at also included the Black Death in Europe, the fall of China’s Ming Dynasty and the conquest of the Americas. According to the study, the legendary Genghis Khan has given the biggest helping hand to the earth’s environment, by killing so many people. After his murderous conquests killed so many people that huge swathes of cultivated land returned to forest and helped remove nearly 700million tons of carbon from the atmosphere.

At a time like this where affects of Global warming could been seen everywhere in devastating scales, in the forms of unusual floods, landslides, draughts and melting of Glaziers which affect the lives of thousands of animal species such as Polar Bears and Penguins, no one but the man-kind is to be blamed for these catastrophes. With our industrial revolutions and never ending carbon emission to the atmosphere, ever growing populations and clearing of forests to accommodate human population and many other human activities has become the focus as the main reasons for Global warming. In other words, expansion of human kind has brought devastating affects to our mother earth.

Julia Pongratz, who headed the research by the Carnegie Institution’s Department of Global Ecology says that humans started to influence the environment thousands of years ago by changing the vegetation cover of the Earth’s landscapes when we cleared forests for agriculture, and the deaths of 40million people as a result of Genghis Khan’s invasions meant that large areas of cultivated land grew thick once again with trees, which absorb carbon dioxide from the atmosphere. Even the events like Black Death in Europe share a widespread return of forests after a period of massive depopulation. But the bloody Mongol invasion, which lasted more than a century and led to an empire that spanned 22 per cent of the Earth’s surface, immediately stood out for its longevity and bigger effect.

Mongol horses were small, but their riders were lightly clad and they moved with greater speed, which later made them the most successful invaders in human history.

An actor portraying legendary Genghis Khan from the award winning movie ‘Mongol’.

And this is how Genghis Khan, who repeatedly wiped out entire settlements, was able to scrub more carbon from the atmosphere than any other invader. After his decades long invasions, and also of his sons and grandsons, the earth is believed to have cooled down.

Genghis Khan was born under the name, Temujin and his father was khan of a small tribe, but he was murdered when Temüjin was still very young. After that, with his mother and five other children, Temüjin was cast out and left to die. From the most brutal beginning possible, Genghis survived to unite the Mongolian tribes and conquer territories as far apart as Afghanistan and northern China. He left a mountain of skulls that remained for years in China. In one instance, the city of Nishapur revolted against Mongol rule. The husband of Genghis Khan’s daughter was killed, and, it is said, she asked that everyone in the city be put to death, and, according to the story, they were.

Kidnapping of women had often caused feuding among the Mongols, and, as a teenager, Temujin had suffered from the kidnapping of his young wife, Borte. After devoting himself to rescuing her, he made it law that there was to be no kidnapping of women. He declared all children legitimate. He made it law that no woman would be sold into marriage. The stealing of animals had caused dissension among the Mongols, and Genghis Khan made it a capital offense.

Mongolian horses are often credited for the successes of Mongol invasions, and in history these Mongolian horses stand out as legendary figures as warhorses. Even today in the snowy wilds of Mongolia the descendants of Genghis Khan’s horses has become a ‘hard to reach’ tourist attraction. Mongol horses were small, but their riders were lightly clad and they moved with greater speed. These were hardy men who grew up on horses and hunting, making them better warriors than those who grew up in agricultural societies and cities. Their main weapon was the bow and arrow.

It is widely popular that Genghis Khan declared freedom of religion throughout his empire. Favoring order and tax producing prosperity, he forbade troops and local officials to abuse people. In 1227, around the age of sixty-five while leading the fighting against the Tangut, Genghis Khan, it is said, fell off his horse and died. Genghis Khan paved the way for his grandson Kublai Khan to become emperor of a united China and founder of the Yuan dynasty. In all, Genghis conquered almost four times the lands of Alexander the Great.