Dams :: essays research papers

Many passel havealready dammed a small menstruum using sticks andmud by the eon they become adults. Humanshave used dams since early civilization, becausefour-thousand years ago they became aware thatfloods and droughts affected their well-being andso they began to build dams to protect themselvesfrom these effects.1 The basic principles of dams remedy apply today as they did before a dam mustprevent water from being passed. Since then,people have been continuing to build and double-dyed(a)these structures, not knowing the full intensity oftheir side effects. The hindering effects of dams onhumans and their environment heavily outweigh thebeneficial ones. The paragraphs below leave provethat the construction and presence of dams alwayshas and will continue to leave devastating effectson the environment around them. Firstly, tounderstand the thesis people must know whatdams are. A dam is a barrier built across a watercourse to feed back or cut back water flow. Damsare classifi ed as either storage, diversion ordetention. As you could probably notice from itsname, storage dams are created to collect or holdwater for periods of time when there is a surplussupply. The water is then used when there is alack of supply. For example many small dams prehend water in the spring, for use in the summerdry months. Storage dams also supply a watersupply, or an improved habitat for lean and wildlifethey may store water for hydroelectricity as well.2A diversion dam is a generation of a commonlyconstructed dam which is built to provide comfortablewater pressure for pushing water into ditches,canals or other systems. These dams, which arenormally shorter than storage dams are used forirrigation developments and for diversion the ofwater from a stream to a reservoir. Diversiondams are mainly built to lessen the effects of floodsand to trap sediment.3 Overflow dams aredesigned to carry water which flow over thiercrests, because of this they must be made ofmaterials which do not erode. Non- overflowdams are built not to be overtopped, and they mayinclude earth or throw off in their body. Often, twotypes of these dams are combined to form acomposite structure consisting of for example anoverflow concrete gravity dam, the water thatoverflows into dikes of earthfill construction.4 Adams principal(a) function is to trap water forirrigation. Dams help to decrease the severity ofdroughts, increase agricultural production, andcreate new worlds for agricultural use. Farmland,however, has its price river bottomlands flooded,defacing the fertility of the soil. This agriculturalland may also result in a loss of natural artifacts.Recently in Tasmania where has been pressure