coastal zone and climate change- India

1. Coastal Zone &
Climate Change
Submitted by:
DIVYA SONI
517

2. INTRODUCTION
• India’s coastal and marine ecosystems include a wide range of
mangroves, coral reefs, sea grasses, salt marshes, mud flats,
estuaries, lagoons, and unique flora and fauna.
• According to Census 2011, nearly 48% of India’s population
from coastal regions is currently living in urban areas
• Coastal areas are exposed to frequent occurrence of cyclones,
storms, and environmental degradation.
• The change in climate is expected to increase the frequency
and intensity of these events and further incite new hazards.

3. CLIMATE CHANGE EVENTS AS A
RESULT OF GLOBAL WARMING
 RISING SEA LEVEL
 STORM SURGES
 SST VARIATIONS

4. SEA LEVEL RISE
• With India close to the equator, the sub-continent would see much
higher rises in sea levels than higher latitudes.
• IPCC has estimated a sea level rise of 1 to 2 mm per year globally.
• 1m rise in sea level will displace more than 7 million people,
destroy more than 5000 square kms of land and 4000 kms of
roads.
• By the end of the 21st century, it is very likely that sea level will rise
in more than about 95% of the ocean area.
• SLR would lead to saltwater intrusion in the coastal areas impacting
agriculture, degrading groundwater quality, contaminating drinking
water, and possibly causing a rise in diarrohea cases and cholera
outbreaks, as the cholera bacterium survives longer in saline water.
• Other implications - flooding, migration to interior, conflicts over
land and water, waste removal problems, health issues

5. Net sea-level-rise trends from past
tide-gauge data

6. Sea level changes-past, present and
future

7. Potential effects of 1mt sea level rise
on India’s coastal area and population

8. STORM SURGES
• Storm surges are also the major cause of
coastal flooding along the east coast of India
• The projected rise in the sea level due to
greenhouse warming may affect the storm
surges and consequently the coastal flooding
in the east coast.
• East coast more vulnerable than west coast
due to higher frequency and magnitude of
tropical cyclone.

9. Damage due to Cyclonic Storms/Heavy
Rains /Flash Floods/Landslides in coastal
states of India (2010-2011 and 2011-2012)

10. SEA-SURFACE TEMPERATURES
• The warming of the
ocean has contributed
significantly to the
observed sea level
rise, through thermal
expansion of sea
water
• Increased the heat
stress of the coral
reefs.
• Affects rainfall
patterns.

11. CURRENT SEA SURFACE TEMPERATURES ANOMALY
• Southeast Indian OceanSouthwest Indian Ocean

12. IMPLICATIONS OF CLIMATE
CHANGE

13. CORAL REEFS
• Coral reefs constantly police fluctuating sea level changes across low lying
coastal terrains
• Protect the coastal populace from strong storm and tidal surges; thus preventing
denudation and subsequent inundation of adjoining landforms from the vagaries
of nature’s fury.
• As the SST are likely to cross the upper thermal threshold of reef- corals,
Bleaching event has been perceived as a major threat to many reef systems,
resulting in the collapse of entire stands of mono specific coral gardens
• OCEAN ACIDIFICATION--which occurs when oceans absorb CO2 from the
atmosphere--is also a threat to coral. As the oceans become more acidic, the
corals' ability to form skeletons through calcification is inhibited, causing their
growth to slow.
• The increasing frequency of tropical hurricanes and thunderstorms, exacerbated
by climate change are another source of coral reef destruction
• Sea level rise caused by melting sea ice and thermal expansion of the oceans
could also cause problems for some reefs by making them too deep to receive
adequate sunlight, another factor important for survival.

14. MANGROVES
• The mangroves act as barriers
against cyclones, avoid coastal
erosion and serve as habitat for a
number of aquatic lives specially
fish, prawns and crabs.
• Frequent occurrences of tropical
cyclones, storms and tsunamis,
have damaged the mangroves of
India
• India lost 40% of its mangrove
area during the last century
• The mean annual change of
mangrove area in India during
1987-2013 is 24.25 ± 82.57
sq.kms
• Due to sea level rise mangroves
tend to move landward, but
human encroachment prevents
this and consequently, the width
of the mangroves decreases

15. Differences in the effect of wave reduction (a) with and
(b) without mangroves

16. COASTAL EROSION
• Waves and storm surges increasingly erode the Indian Coasts
• As much as 45% of India’s 8,414-km long coastline is facing
erosion
• Close to 19% of the coastline is stable and about 36% is showing
accretion, or expansion. of Bengal.
• The Andaman and Nicobar Islands face the most erosion, with
close to 89% of the shoreline eaten away by the Bay
• At the other end of the spectrum is Tamil Nadu, which has
gained the most new shoreline, with 62% of its coast gaining
land.
• Goa has the highest percentage (52%) of stable shoreline.

18. SOCIO ECONOMIC CHALLENGES
• Disputes over allocation of water and power
• Migration to safe locations – competition for land
and water
• Financial burden associated with rehabilitation
and reconstruction
• Impact of floods on infrastructure
• Setbacks in Coastal Tourism
• Impact on industries, ports and trade etc. –
current economic growth maybe haltered