The Common Problems Associated With Dams Environmental Sciences Essay

The Common Problems Associated With dikes Environmental Sciences EssayA obturate is a physical barrier constructed across a river or a pissing modality to control the flow of or raise the level of water. The purpose of such a construction may be flood control, irrigation needs and extension of hydroelectricity. A obstruct is a barrier across flowing water that obstructs, directs or slows down the flow, often creating a reservoir, lake or impoundments. Most dams befool a section called a spillway or weir over which, or through which, water flows, either intermittently or continuously, and many pass on hydroelectric causality generation systems installed. The dams are advantageous in more than a single way. Advantages of a dam are listed belowThey are helpful in preventing floods.They manage as a solution to energy crises by generating hydroelectricity.They prove to be helpful in irrigationThey better the water transport.And last but non the to the lowest degree they attrac t tourists. dam ups are too beneficial for mankind but at the equivalent time they are harmful too in several ways. Disadvantages of a dam are listed belowBuilding a dam is an expensive affair.For building a dam a large population of nearby knowledge domain is moved.The living environment of aquatic and semi aquatic flora and fauna gets disturbed in lower case.Collapse of the dam causes gigantic damage.Fig 1 Dam www.timboucher.comNow in this paper we will be viewing and observing the main causes of Dam Failure along with case study for both cause. Main causes of Dam Failure areSpillway designing error.Sliding of view into the dam lake.Poor maintenance especially of dismissal pipes.We will be discussing all of the above mentioned causes one by one. Besides all the above causes there is one more drive due to which dams are collapsed. In technical foul terms it is called heedful Dam Failure. This happens during the course of War. When force of one country destroys the dam of o ther country deliberately then this is known as Deliberate Dam Failure. As this cause is nat a common cause so we would not consider this in our study.SPILLWAY DESIGN ERRORSpillway (shown in Fig 2) is a characteristic structure of a dam which is used to provide controlled release of flows of water from the dam into the downstream. Spillways release floods so that the water does not overtop and damage or even destroy the dam. There are two ways of spillways Controlled and Uncontrolled.Controlled Spillway It has gates which regulate the water. This design gives us an probability to exploit the full height of the dam and flood waters can be released as required by opening one or more gates.Uncontrolled Spillway It does not have gates, when the water rises above the lip of the spillway it begins to be released from the reservoir. The rate of discharge of water is controlled only by the sagacity of water within the reservoir. All of the storage volume in the reservoir above the spillwa y lip can be used only for the ephemeral storage of floodwater, and cannot be used as water supply storage because it is normally empty.Fig 2 Spillway www.wikipedia.comCASE STUDY The atomic number 16 carve up DamAs a case study under this cause of Dam Failure we will study the demolition of South secernate Dam which was located on Lake Conemaugh, an artificial water body located near South Park, Pennsylvania, USA. On May 31, 1889, the South Fork Dam failed and 20 billion wads of water from Lake Conemaugh burst through and raced 14 miles (23 km) downstream, causing the Johnstown Flood.History of South Fork DamThe South Fork Dam was construct by the dry land of Pennsylvania between 1838 and 1852 as a reservoir for the canal basin in Johnstown. The dam is located 14 miles upstream from Johnstown. The Comenaugh River runs through the bone marrow of Johnstown and it had been make narrower in order to build more structures on it banks. The river was susceptible to flooding due to its location on a flood plain. The Commonwealth of Pennsylvania sold the dam to the Pennsylvania Railroad in 1857. With the arrival of rail service in 1852, the use of the canal for delivery of goods took a downturn. The South Fork Dam was abandoned and allowed to go into a state of disrepair. In 1862, part of the culvert gave way but was never repaired. In 1879, a group of business community formed a company and called it the South Fork Hunting and Fishing Club. They purchased the dam with the intention of building a summer resort on Lake Comenaugh for laden Pittsburg families. Plans included lowering the dam in order to build a road on top and raising the level of the lake. The club continued to groom alterations to the dam and in the end, the lake was 450 feet higher than Johnstown.suit101.comFrom the above abstract we can easily make out that the ill maintenance of the spillway and rising of the level of river do the condition worse and finally the continuous rain do the D am collapsed. After the Dam gave up nearly about 20 one thousand million tons of water spilled over the dam and Jhonstown was hit without any prior warning. The water headed towards the town with a speed of nearly 40 miles per hour. The flood played slaughter and made over 2,200 people lose their lives and all over damage was estimated to cost $17 million. This was the first major disaster faced by the newly-formed American Red Cross. Aid came from 18 countries across the globe. The South Fork Dam Break is shown BelowFig 3Beside the Spillway failure there are other causes which are responsible for(p) for the Disaster and they areHeavy and continuous Rainfall.Rising water caused erosion of new embankment which was made up of mud and straw.Fig 3 South Fork Dam Break www.accuweather.comPrecautions which could have saved South Fork DamThe main cause of the break was Spillway design error. There were insufficient spillways which made the enormous amount of water to spill. If there had been more spillways then the disaster would have been avoided.The damaged parts of the dam should have been repaired.The new parts should have been made up of concrete instead of stone, mud and straw.SLIDING OF MOUNTAIN INTO THE DAM LAKEA dam is made at the base of a river and in between a valley which means that the lake or water body which is dammed has mountains on both side of it. Now as a dam is made the inborn geological balance is disturbed and these mountains get loosen up and develops cracks which causes landslides to occur. These landslides pose a great threat when they fall in the lake. If a landslide of great volume falls in the lake then it raises the water level to a great extent and that too suddenly. This sudden rise makes a huge amount of water to spill over the dam causing tsunami (seiche wave). This wave brings a massive flood and destruction to the valley below which wipes a great area.CASE STUDY The Vajont DamAs a case study under this cause of Dam Failure we will study the demolition of Vajont Dam shown in Fig 4 which was located on Vajont River under Monte Toc, 100 km north to the Venice, Italy. It was responsible for the deaths of approximately 2,000 people in a 1963 landslide. atomic number 53 of the highest dams in the world, it was 262 meters (860 ft) high, 27 meters (89 ft) thick at the base and 3.4 meters (11 ft) at the top. The dam was built by SADE (Society of Adriatic Energy Corporation), the electricity supply and distribution monopolist in North-Eastern Italy.History of Vajont DamThe construction work of the dam started in 1950. In 1959 some slides were noticed and new studies were made and the experts told SADE that the side of heighten Toc is unstable and is likely to collapse if the filling is continued. The study and experts were ignored completely. In October 1959 the construction was complete and in February 1960 SADE was authorized to start filling the basin. As soon as the filling started and reached to certain l evel till summers of 1960 minor land slides started taking place. But even these slides were ignored and the few journalists who raised their utter were sued. Finally on 4 of November 1960 a landslide of about 800,000 isometric meters collapsed in the lake. This made SADE to halt filling but it was started again subsequently lowering the level by 50 meters and start building an artificial gallery. The minor slides kept on taking place and officials of SADE kept on predicting the disaster but they were ignored.On 9 October 1963 at approximately 1035pm, the combination of drawing-down the reservoir and heavy rains triggered a landslide of about 260 million cubic meters of forest, earth, and rock, which fell into the reservoir at up to 110km per hour (68mph). The resulting displacement of water caused 50 million cubic meters of water to over-top the dam in a 250-metre high wave.6 Despite this, the dams structure was largely undamaged. Approximately 1900 to 2500 people were dead and 350 families were completely wiped off.The major causes of this disaster areThe heavy 50 million cubic meter landslide into the lake which made the tsunami wave rose.The other minor land slides in the lake and in the artificial gallery.Heavy rainfall which paved the highway for the disaster.Major causes for the land slides areDisturbance in the geological balance of Mount Toc.Continuous filling of the basin.Time to time rainfall.Fig 4 Vajont Damwikipedia.comPrecautions which could have saved South Fork Dam If anyhow the land slide could be prevented then the disaster might have been avoided. The landslide can be prevented by following two methodsPlantation More and more plants on the seaward side of the mountain. The roots of the plants help in binding the rocks and soil together and prevent erosion thus land sliding. Terrace plantation is a good option.By artificial mountain binding In this process the mountain is bound with the help steel net which prevent slides and even if lan d slide, the net prevent it from falling.POOR MAINTENANCE ESPECIALLY OF OUTLET PIPESOutlets came in consecrate of designs, sizes, materials and type of control. Most of the controlling mechanisms and conduits are usually submerged and are pretty tedious to access for maintenance as well as inspection. This is the reason of negligence and some serious problems start developing. The problem can range from the control works becoming inoperable to the conduit deteriorating to the point of embankment failure. Proper inspection of the button usually requires advanced planning to allow outflows to be shut off and inundated areas to be pumped out.CASE STUDY Lawn Lake DamNow as a case study under this section we will make a thorough study of Lawn Lake Dam Fig 5. This dam failure occurred due to the disrepair of the outlet pipe which was located at the remote and tedious location. The continuous negligence of remotely situated leaky pipes caused the disaster when on July 15, 1982 at 6 a.m. 830,000 m3 of water exploded out of the faulty pipes. This enormous amount of water caused a flash flood and priced $31 million.History of Lawn Lake DamOriginally the Lawn Lake was a natural lake covering a surface area of over 66,000 m3. It was situated at a height of 3,400 m in the rocky mountain. In 1903 some farmers seeking irrigation facilities out of this lake, built a dam and the covering land of the lake increased to 190,000m3. It was started in 1902 and the dam was completed in 1903. The dam increased the storage depicted object of this natural water body. This dam was built in the eastern part. The water from this dam was released through the steep channel into the Big Thompson River. As the dam was built in the rocky mountain, its design was such that it made the location of outlet pipe quit remote. Bearing the negligence of officials the dam survived 80 long years.On the morning of 15 July 1982 the dam collapsed releasing 228 million gallons of water all of a sudden. Th is huge amount of water poured through the steep and narrow mountainside. It is express that there was tremendous sound and the earth shook. The release rate of water was 510 m3/s. Though this great aquatic rampage killed only one person populate alongside but economically the cost of this disaster was estimated to be $31 million. The water got poured in the river and hit the cascade dam resulting in downfall of the same adding more amount of water to the flood. This flood destroyed the Aspenglen campground. Then later on the flood water entered the town of Estes Park and caused great damage to the downtown shops after which the flood joined Thompson River. This flood deposited an alluvial fan of debris in Horseshoe Park.Fig 5 Alluvial Fan wikipedia.comPrecautions that could have saved the Lake Lawn Dam Only two precautions would have saved the disastrous end of Lake Lawn Dam and they areIf the dam would have been design in such a way that the outlet pipes could have been easily accessed then the repair work wont have been delayed and the leakage could have been avoided.Timely repairing work of the dam would have saved this great damage.