Question

One of the measures for preventing coastal erosion is
A.
construction of dams across the rivers
В.
restrict sand mining in coastal areas
avoid the construction of large dams and reservoirs
D
Construction of high rise buildings​

Answer 1

Answer:

all of these

Explanation:

A.

construction of dams across the rivers

В.

restrict sand mining in coastal areas

avoid the construction of large dams and reservoirs

D

Construction of high rise buildings

Answer 2

Answer:

Coastal erosion (disruption) is the phenomenon where coastal erosion and coastal drift sand balance is lost, coastal sediments are lost and shoreline retreat is called coastal erosion (destruction).

Explanation:

                    A.construction of dams across the rivers

Answer is: Dams are built on rivers because dams play an important role in the overall infrastructure of the country. I dams provide a variety of economic, environmental and social benefits, including recreation, flood control, water supply, hydroelectric power, waste management, river navigation and wildlife habitat.

• Flood Control: Apart from helping farmers, dams help prevent loss of life and property due to floods. Flood control dams hold flood waters and then either release or store them in the river below the dam or divert the water for other uses. For centuries, people have built dams to help control devastating floods.

• Water storage: Dams create reservoirs throughout the United States that supply water for many uses, including industrial, municipal, and agricultural.

• Irrigation: Ten percent of the US crop is irrigated using water stored behind dams. Thousands of jobs are associated with the production of crops grown with irrigated water.

• Electricity generation: The United States is one of the largest producers of hydroelectric power in the world, second only to Canada. The dams generate over 103,800 MW of renewable electricity and meet 8 to 12 percent of the country's electricity needs. Hydropower is considered clean because it does not contribute to global warming, air pollution, acid rain or ozone depletion.

                        В. restrict sand mining in coastal areas

                          avoid the construction of large dams and reservoirs

Answer is: As a result, environmental damage occurs: floods, landslides and water pollution. Beach sand mining that is not managed properly will disturb the balance and function of the environment such as soil humus erosion, the formation of large holes and result in abrasion

    Disadvantages of Sand casting

1.  Handmade process
2.  Low strength
3.  Low dimensional accuracy
4.  Rough surface quality

            D. Construction of high rise buildings​

Answer is: Erosion persists even where preventive measures such as sea dykes are constructed. Beach scour has been found along coasts with sea-dyke protection.

                              Benefit of high rise building

Seawalls: Seawalls are one particularly effective way to prevent erosion. These are structures that are built along the coastline to stop waves from ever coming into contact with the sand/shore on the opposite side