Rivers are systems that require management in terms of flooding, supply, and pollution control. Discuss various strategies using different case studies.
Every river experiences a flood in some point in time. This may be due to an effect of heavy rain or humans tampering with the surroundings of the river. However due to the large build up of settlements around rivers flood control is needed as many lives and settlements can be lost during such an event.
A good example of flood control can be seen along the Yangtze River. The Yangtze River is the third longest river in the world and is situated on the Tibetan Plateau in china. It reaches a length of 6300km and has a drainage basin of more than 1,683,500 square meters.
Since 1931 seven major floods have been recorded. In 1931 there were estimated 28 – 40 million people affected 140,000 of which were deaths. In 1954 there were 33,000 deaths. In 1981 and 1991 floods arose which submerged large areas of land. In 1995 there were 1300 deaths and an astonishing 100 million people affected.
In 1998 the largest flood hit the area surroundings of the Yangtze River, recorded for over half a century. The level of which the river rose to was maintained for over two months. There was an estimated 3000 deaths. 5.6 million homes were washed away, 30million made homeless and extremely large areas of cropland destroyed. 100,000 soldiers and police were needed to strengthen the jingjiang and other levees. They had to work for in teams 24 hours 7 days a week for 2 months. On July the 21st, an uncanny 280mm of rain fell on Wuhan in 24 hours. The next day the city experienced the first of the several flood peeks, which occurred during a two-month period. By the 2nd of August the Dongting lake reached the all time high where there was nowhere for extra water to go as areas around it had already been flooded for 30 or more days. By this stage the government had given the information that they were sacrificing the smaller villages and towns in order to lessen or stop the blow for the larger settlements.
