Beaches in Visakhapatnam are now heading towards a disaster, say experts
- February 12, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Beaches in Visakhapatnam are now heading towards a disaster, say experts
Subject: Geography
Section: Indian Physical; Geography
Concept:
- It was reported in the Rajya Sabha that around 28.81 km of coastline in Visakhapatnam is prone to erosion.
- In 1930 two ships were sunk near the Dolphin’s Nose in Vishakhapatnam to create a breakwater to control sedimentation at the mouth of harbour (during the construction of Visakhapatnam Port).
- Erosion was further aggravated by the construction of two breakwaters during the construction of the Outer Harbour (in the 1970s).
Significance of Beaches
- Beaches are dynamic landforms and the sand erosion and deposition of sand are majorly due to the high wave action and high wave energy.
- Experts point out that the beaches act as cushions between the high wave action of the sea and the landmass.
- Continuous nourishment of beaches through the natural process is essential and, if disturbed it might result in severe erosion.
- Due to the construction of breakwaters in the south, the sand is unable to reach the north parts hampering the natural nourishment of beaches.
- Beaches should be considered part of the sea instead of land.
Coastal erosion
- Coastal erosion is the process by which local sea level rise, strong wave action, and coastal flooding wear down or carry away rocks, soils, and/or sands along the coast.
- Erosion and Accretion: Erosion and accretion are complementary to each other. If the sand and sediments have drifted from one side, it must accumulate somewhere else.
- Soil erosion is the loss of land and human habitation as sea water washes off regions of soil along the coastline.
- Soil accretion, on the other hand, results in an increase in the land area.
- Impact:
- Recreational activities (sun bathing, picnicking, swimming, surfing, fishing, boating, diving, etc.) may be affected if existing beaches are reduced in width or disappear altogether. Also, there can be an impact on livelihoods of coastal communities.
- Measures:
- Coastal habitats such as Mangroves, Coral Reefs and lagoons are recognized as the best defence against sea storms and erosion, deflecting and absorbing much of the energy of sea storms.
- Therefore, it is important to maintain these natural habitats for shore protection as well as for environmental conservation.
Causes for coastal erosion
- Natural Phenomena:
- Wave energy is considered to be the primary reason for coastal erosion.
- Natural hazards like cyclones, thermal expansion of seawater, storm surges, tsunami etc due to the melting of continental glaciers and ice sheets as a result of climate change hamper the natural rhythm and precipitate erosion.
- Littoral Drift:
- Strong littoral drift resulting in sand movement can also be considered as one of the major reasons for coastal erosion.
- Littoral drift means the natural movement of sediment along marine or lake shorelines by wave action in response to prevailing winds.
- Anthropogenic Activities:
- Dredging, sand mining and coral mining have contributed to coastal erosion causing sediment deficit, modification of water depth leading to longshore drift and altered wave refraction.
- Coastal erosion has been sparked by fishing harbours and dams constructed in the catchment area of rivers and ports reducing the flow of sediments from river estuaries.