Coastal Flooding: Causes, Impacts, and Mitigation Strategies

Description

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Context:

According to a study paper published in the journal Frontiers in Forest and Global Change, Global warming is raising sea level rise and making floods more common in some areas.

Key findings of the study

Researchers used Dendrochronology to understand how trees respond to conditions. Scientists estimate when a tree forms a tree ring and develop a time-wise correlation between a climatic condition and the tree's response.

The study highlights that sea levels were increasing by around 2 mm/year in 1993. This rate has since doubled and climate researchers expect floods in coastal areas will increase threefold by 2050.

The study underscores the importance of local conditions on tree growth in coastal forests. Non-linear relationship that may contribute to tree response.

What is Dendrochronology?

Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed in a tree. As well as dating them, can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from the wood of old trees.

About Coastal Flooding

It is a sudden and abrupt inundation of a coastal environment caused by a short-term increase in water level due to a storm surge and extreme tides. The magnitude and extension depend on the coastal topography, storm surge conditions and broader bathymetry of the coastal area.

Coastal flooding is generally a natural process and constitutes an important part of the natural coastal dynamics, especially for salt marshes and mangrove forests. In areas with human activities, however, it can constitute a major challenge and lead to loss of property and lives.

Over the last 200 years, it is estimated that about two million people have been killed in flood events mainly in South Asia and with growing coastal populations and sea level rise, the world faces increasing potential for coastal flood disasters.

Causes of Coastal Flooding

Rising Sea Levels: Global warming is causing sea levels to rise, increasing the frequency and intensity of coastal flooding. As per the UN's Intergovernmental Panel on Climate Change, 2014, there is a high degree of certainty that sea levels will rise by between 28 - 98cm by 2100, with the most likely rise being 55cm by 2100.
Storm surges: A lot of coastal flooding is a result of storm surges. Storm surges are short-term changes in sea levels caused by events such as tsunamis and cyclones. A storm surge is only measured by the water level that exceeds the normal tidal level, excluding waves.
Extreme Weather Events: Cyclones, storms, and tsunamis can exacerbate coastal flooding, leading to severe damage and loss of life. For e.g. the Netherlands, IJsselmeer polders, is subject to subsidence due to water abstraction via crop evapotranspiration
Unsustainable Coastal Development: Construction of infrastructure, such as ports and resorts, in coastal areas can increase vulnerability to flooding.
Deforestation and Erosion: Deforestation and erosion of coastal ecosystems can weaken natural barriers against flooding. Erosion is when materials are being worn away, for example, by waves and soft geology and transported elsewhere by natural forces such as wind or water.
- - An example is Holderness, in Yorkshire, England. Waves, storms and tidal surges constantly batter the coastline of Holderness.

Examples of coastal flooding

As a low-lying country, the Netherlands has had its fair share of floods. One of the biggest floods was the North Sea flood of 1953.

On 23 August 2005, Hurricane Katrina hit New Orleans, Louisiana (US), leaving behind a trail of destruction.

On 26 December 2004, one of the deadliest natural disasters in recorded history happened: an all-powerful tsunami, caused by an undersea earthquake, hit the countries and islands in the Indian Ocean.

Impacts of Coastal Flooding

Loss of Life and Property: Coastal flooding can result in significant loss of life and property damage, particularly in densely populated areas.
Infrastructure Damage: Roads, bridges, and other infrastructure can be severely damaged or destroyed, disrupting essential services.
Economic Disruption: Coastal flooding can disrupt economic activities, including tourism, fisheries, and agriculture.
Environmental Degradation: Coastal ecosystems, such as mangroves and coral reefs, can be severely impacted by flooding, leading to loss of biodiversity.

Mitigation Strategies

Integrated Coastal Zone Management (ICZM): Implementing ICZM plans to promote sustainable development and reduce vulnerability to coastal hazards.

Examples

Building sea walls, e.g. on the North Norfolk coast and 3m sea wall on Malé.

Constructing storm-surge barriers, e.g. The Thames barrier and the Eastern Scheldt, the Netherlands.

Building earth dams, like the bunds in Bangladesh.

Coastal Afforestation: Planting trees and mangroves along coastlines can act as natural barriers against flooding.
Early Warning Systems: Developing and implementing early warning systems to alert communities of impending floods.
Infrastructure Upgrades: Strengthening coastal infrastructure, such as seawalls and dykes, to enhance resilience.

Case study: Through the restoration of mangrove forests, e.g. Sri Lanka. As a result of the 2004 tsunami, 6,0000 were killed in one village alone where the mangroves had been removed compared to only two deaths in an adjacent village protected by a mangrove forest.

Climate Change Adaptation: Implementing measures to adapt to the impacts of climate change, such as relocating vulnerable communities and promoting climate-resilient development.

India's Coastal Vulnerability

Coastline Statistics:

India's coastline spans 7,516 kilometers, encompassing 5,422 kilometers on the mainland and 2,094 kilometers across islands belonging to nine states and four Union Territories.

This coastline supports 90% of the country's trade and encompasses 3,331 coastal villages and 1,382 islands.

According to an analysis, about 43.5 of the coastline is under highly vulnerable zone and about 1 is under a very highly vulnerable zone.

India’s Efforts to Combat Climate Change

Aspect	Details
Renewable Energy Expansion	India has set ambitious targets to significantly increase renewable energy capacity. The country is heavily investing in solar and wind energy projects to reduce its dependence on fossil fuels and cut down on greenhouse gas emissions.
International Commitments	India is a signatory to the Paris Agreement, pledging to reduce its carbon intensity and increase the share of non-fossil fuel energy in its overall energy mix. It aims to meet 50% of electricity demand from renewable energy sources by 2030.
Afforestation and Forest Conservation	India has launched programs to enhance forest cover, restore degraded land, and encourage sustainable forest management, acknowledging the importance of forests in carbon sequestration and climate regulation.
Clean Transportation	India aims for 30% of its market to consist of electric vehicles by 2030. The government provides incentives and subsidies to support both the production and use of EVs.
Climate Resilience	India is investing in improving climate resilience and adaptation, particularly in vulnerable sectors such as agriculture, water resources, and coastal regions.
International Cooperation	India is actively participating in international initiatives such as the International Solar Alliance and the Coalition for Disaster Resilient Infrastructure to address climate change challenges.

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FLOODS

Sea Level Rise |

climate change and flooding

Flood Risks In India

why do floods & droughts simultaneously ravage india?

Source:

THE HINDU

PRACTICE QUESTION

Q.What is Coastal Flooding? Discuss the effectiveness of India's coastal flood management strategies and suggest recommendations for enhancing resilience and sustainability. (150 words)