The Common Problems Associated With Dams Environmental Sciences Essay

The Common Problems Associated With occludes Environmental Sciences EssayA plainlych is a physiologic barrier constructed across a river or a piddleway to determine the flow of or raise the take of irrigate supply. The purpose of such a construction may be flowage control, irrigation needs and generation of hydroelectricity. A close up is a barrier across flowing irrigate that obstructs, directs or slows down the flow, often creating a beginning, lake or impoundments. Most dyke ups flip a section c all tolded a spillway or weir everyplace which, or through which, irrigate flows, either intermittently or doggingly, and many cod hydroelectric power generation systems installed. The close ups be advantageous in to a greater extent than a single way. Advantages of a dam ar listed at a lower placeThey are ministrant in preventing gushs.They serve as a solution to energy crises by generating hydroelectricity.They prove to be helpful in irrigationThey better the water transport.And hold unwrap scarcely not the least they attract tourists. occludes are too upright for mankind but at the same age they are deadly too in several shipway. Disadvantages of a dam are listed belowBuilding a dam is an expensive affair.For building a dam a huge population of nearby area is moved.The living environs of aquatic and semi aquatic flora and fauna gets disturbed in lower fibre.Collapse of the dam causes great scathe. physique 1 decameter www.timboucher.comNow in this paper we result be viewing and observing the main causes of jam Failure along with case depicted object for all cause. Main causes of Dam Failure areSpillway designing error. glide of mountain into the dam lake.Poor maintenance especially of bulge outlet pipes.We will be discussing all of the above mentioned causes one by one. Be berths all the above causes there is one more(prenominal) reason due to which dams are collapsed. In technical terms it is called Deliberate Dam Fail ure. This happens during the course of War. When fight of one country destroys the dam of separate country deliberately accordingly this is known as Deliberate Dam Failure. As this cause is nat a common cause so we would not consider this in our study. fall DESIGN ERRORSpillway (shown in Fig 2) is a character structure of a dam which is utilise to provide controlled release of flows of water from the dam into the downstream. Spillways release pelters so that the water does not oer book binding and damage or even destroy the dam. There are twain ways of spillways Controlled and Uncontrolled.Controlled Spillway It has gates which regulate the water. This design gives us an opportunity to proceeding the full height of the dam and flood waters flock be released as required by opening one or more gates.Uncontrolled Spillway It does not have gates, when the water rises above the oral cavity of the spillway it begins to be released from the reservoir. The rate of discharge of wat er is controlled only by the depth of water within the reservoir. All of the computer storage volume in the reservoir above the spillway lip can be used only for the temporary storage of floodwater, and cannot be used as water supply storage because it is normally empty.Fig 2 Spillway www.wikipedia.com cutting theatre of operations The southeast severalise DamAs a case study down the stairs this cause of Dam Failure we will study the demolition of south jumpstart Fork Dam which was located on Lake Conemaugh, an coloured water ashes located near South Park, Pennsylvania, USA. On may 31, 1889, the South Fork Dam failed and 20 million 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 build by the state of Pennsylvania between 1838 and 1852 as a reservoir for the canal john in Johnstown. The dam is located 14 miles upstream from Johnstown. The Comenaugh River run s through the nucleus of Johnstown and it had been do narrower in order to build more structures on it banks. The river was suasible 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 slant of goods took a downturn. The South Fork Dam was abandoned and allowed to go into a state of dis speed up. In 1862, part of the culvert gave way but was never repaired. In 1879, a group of businessmen 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 wealthy 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 make alterations to the dam and in the demolition, the lake was 450 feet higher than Johnstown.suit101.comFrom the above abstract we can e asily make out that the ill maintenance of the spillway and rising of the level of river do the peg down worse and finally the continuous rain made the Dam collapsed. later on the Dam gave up nearly about 20 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 contend havoc and made over 2,200 nation lose their lives and all over damage was estimated to cost $17 million. This was the first major disaster approach 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 the Disaster and they areHeavy and continuous Rainfall.Rising water caused corrosion of new embankment which was made up of bollocks up and straw.Fig 3 South Fork Dam Break www.accuweather.comPrecautions which could have salve South Fork Da mThe main cause of the display was Spillway design error. There were insufficient spillways which made the enormous total of water to spill. If there had been more spillways accordingly the disaster would have been avoided.The change 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 block 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 natural geological balance is disturbed and these mountains get loosen up 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 abruptly. 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 terminal 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-central to the Venice, Italy. It was responsible for the deaths of approximately 2,000 people in a 1963 landslide. One 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 parachutinged in 1950. In 1959 some slides were noticed and new studies were made and the experts told SADE that the side of Mount Toc is unstable and is likely to collapse if the filling is continued. The study and experts were snub completely. In Oct ober 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 level till summers of 1960 minor land slides started taking place. But even these slides were cut and the few journalists who raised their voice were sued. Finally on 4 of November 1960 a landslide of about 800,000 cubic meters collapsed in the lake. This made SADE to assay filling but it was started again afterward 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 uncivilised into the reservoir at up to 110km per hour (68mph). The resulting version 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 path 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 index have been avoided. The landslide can be prevented by following two methodsPlantation More and more plants on the seaward side of the mountain. The grow of the plants help in binding the rocks and soil together and prevent erosion thus land sliding. Terrace pl antation is a good option.By artificial mountain binding In this process the mountain is bound with the help steel benefit which prevent slides and even if land slide, the net prevent it from falling.POOR MAINTENANCE ESPECIALLY OF OUTLET PIPESOutlets came in revolve 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. strait-laced inspection of the outlet 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 wh ich was located at the remote and tedious location. The continuous negligence of remotely situated drippy 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 covert 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 want irrigation facilities out of this lake, built a dam and the covering land of the lake increase to 190,000m3. It was started in 1902 and the dam was completed in 1903. The dam increased the storage capacity of this natural water body. This dam was built in the east 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. This huge amount of water poured through the steep and narrow mountainside. It is said that there was tremendous get going and the earth shook. The release rate of water was 510 m3/s. Though this great aquatic rampage killed only one person camping 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 after 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.