Biology

Dams

What is a Dam? A dam refers to a structure that is built on rivers and streams. The main purpose of dams is that they facilitate the conservation of water. Water dams are not a modern concept as they have been in existence for many centuries. Historically, dams in India or elsewhere have been very useful in the development of civilizations. Furthermore, a dam is a spectacular feat of infrastructure. These great infrastructural structures have been utilized by civilizations.

Amazingly, it has been in existence since way back in the fourth century B.C.E. This way the civilizations over the years have been able to funnel water via the cities and agricultural fields. Moreover, the use of dams takes place for the prevention of floods, regulating the flow of water in rivers as reservoirs, facilitating irrigation, generation of energy, etc. A dam provides various advantages to a country- social, economic, and environmental.

dams

                                                                                                                                       

How are Dams Built ?

A dam is a structure whose building takes place across a river or stream. Holding back water is the main purpose of the dam.

The use of different materials has taken place to build dams over the centuries. In the ancient era, dam builders made use of natural materials like clay or rocks for building a dam. Moreover, nowadays, the use of concrete takes place by modern builders.

For a manmade dam, the creation of artificial lakes known as reservoirs takes place. Experts use these reservoirs to store water for use in housing, industry, and farming. A dam comes in useful for various other activities like boating, swimming, fishing, and other leisure activities.

The first people to build a dam were the ancient Mesopotamians. Jawa Dam is the world’s oldest known dam that is in present-day Jordan. Amazingly, it was built way back in the fourth-century B.C.E.

A dam is a great help to farmers as it can provide them with a steady source of water. This significantly improves the irrigation of crops. Most noteworthy, dams in India and other populous countries are very useful to feed a growing population.

The conservation of water that takes place by a dam can raise some problems. This is because it can cause a major transformation of the habitat in various areas like biological, physical, chemical, or temperature. Due to such changes, the habitat attracts invasive species, thereby becoming hostile for the native aquatic lives.

There can be an increase in the incidence of the disasters like erosion, extinction, landslides, and earthquakes due to a dam. Furthermore, sometimes a major dam can collapse, thereby leading to a major catastrophe. This can lead to hurricanes in earthquakes.

Advantages of Dams

There are some tremendous advantages that come with dams in India and elsewhere. Moreover, this makes it clear that why governments invest so much money into their constructions. Some of the benefits of building a dam are:

  • With the assistance of hydroelectric power, the generation of electricity takes place at a steady rate.
  • For the preservation of water.
  • For irrigation or other activities, the reservoir built behind may also be used.
  • The buildup of water within the lake is ensured when required.
  • They facilitate storing energy when the release of water takes place for electricity production.
  • The electricity generated by the dams minimizes the production of greenhouse gases.

Negative Impact of Dams

In spite of the several advantages that dams offer, they do pose some challenges to the environment. The below points bring out the negative point of dams:

  • Impact on Aquatic Animals: The flow of streams and rivers is very important for aquatic animals. This is because these animals rely on this flow for the purpose of reproduction.  Most noteworthy, water dams construction can endanger this as it acts as a blockade for aquatic animals.
  • Impact on Erosion: The construction of dams contributes to soil erosion as it eats up most of the surrounding landmass. Furthermore, landslides near the shoreline are often witnessed at a landmass that encompasses reservoirs. This causes significant destruction in the surrounding landmass in a gradual manner.
  • Impact on Cost: The construction of dams is a very expensive affair and it also has a huge labour requirement.  Moreover, even if the utilization of a dam takes place for power generation, it would still take several years or decades to recover the investment cost.
  • Impact on Relocation: Relocation can follow the construction of a dam. Furthermore, the need for relocation comes due to the threat of landslides or earthquakes. As such, humans have to relocate their properties and business to avoid potential danger or harm.
  • Impact on Water Bodies:  Dams can sometimes block beneficial sediments. Furthermore, aquatic life depends on these sediments. Besides, these sediments play a crucial role in the carbon cycle.
  • Impact on Groundwater: The reservoir can lead to the reduction of groundwater due to the gradually deepening of the river bed. As such, access to groundwater will be denied to the trees and plants in the landmass. Consequently, this leads to the ruining of both marine and terrestrial life forms balance.

How to Make Dams More Environmentally Friendly?

As you have seen, dams can be quite damaging to the environment. However, this does not mean that one cannot remedy it. Below are the measures to make dams more environmentally friendly.

  • Making the Dams Fish-Friendly

A dam that is around rivers can disrupt the ecosystem in that water body. Furthermore, the fish passing via the turbines may face death or injury. As such, the experts must find a way to prevent fish from moving through the turbines.

  • Minimizing Greenhouse Gases Emissions

Hydropower is not very friendly to environmentally friendly as people think it to be. As such, the dam builders must ensure that the greenhouse gases emissions must be minimized. Moreover, this way, a dam would become safe for the environment in general.

  • Utilizing The Currents

Working with the currents is another way of making the dam more environmentally friendly. For this, the engineers must put turbines in streams and rivers in such a manner that they generate electricity without disturbing the water flow. This way the generation of electricity takes place in a natural way.

FAQs For Dams

Question 1: What are the various types of dams on the basis of structure?

Answer 1: On the basis of structure, the dams are of the following types:

  • Arch dam
  • Gravity dam
  • Arch-gravity dam
  • Barrage dam
  • Embankment dam
  • Fixed-crest dam
  • Earth-fill dam
  • Concrete-face rock-fill dam
  • Rock-fill embankment dam

Question 2: What are the various functions of dams?

Answer 2: Below are the various functions of dams:

  • Power generation
  • Stabilizing water flows
  • Water supply
  • Land reclamation
  • Water diversion
  • Flood prevention

Question 3: What are the various considerations that experts must keep in mind when building a dam?

Answer 3: The various considerations that experts must keep in mind when building a dam are as follows:

  • Permeability of the surrounding rock or soil
  • Water table
  • Earthquake faults
  • Impact on wildlife, forest, habitations, and river fisheries
  • Landslides and slope stability
  • Peak flood flows
  • Reservoir silting
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