Adaptation to climate change in the countries of - Mekong River ...

Existing knowledge of national climate change
Water resources are particularly vulnerable to the effects of climate change. Water runoff
from the Mekong River Delta of Viet Nam to the East Sea is 505 billion m 3 /year. The spatial
and temporal distribution of runoff is very uneven; more than 80% of run-off is concentrated in
summer (5 – 6 months), while the rest (20%) occurs during the 6 – 7 months of the dry season
(Southern Institute for Water Resources Planning, 2008c).
Due to global warming, the planting boundaries of some crops could change as temperature
and rainfall patterns are modified. Due to abnormal changes in rainfall intensity, flood
inundation and drought could occur more frequently. Significant cultivation areas in Mekong
delta could be under salt water due to sea level rise. SEA START RC (2006) found that rice
production in the Mekong Delta in Viet Nam may be severely impacted by climate change,
especially summer autumn crop production, where yield may be reduced by over 40%. Food
scarcity could increase as supply fails to meet the demands of a growing population. The
total area of agricultural activities could be reduced resulting in food scarcity and higher food
prices that could affect not only this region, but the whole country given the importance of the
Mekong Delta for national food production.
The area of mangrove forest in the region is expected to decrease due to SLR, increased
incidence of droughts, and increased erosion and wave action (Phan and Le, 2008). Terrestrial
forest ecosystems could also be affected with changes in temperature and drought incidence
leading to increasing danger of forest fire development and spreading of plant pests and
diseases. Salinity intrusion due to storm surge, extreme tidal flooding and SLR in the Mekong
Delta is expected to lead to a reduction in the area and quality of habitat for freshwater
organisms and affect the vertical distribution structure of ecosystems.
Infectious diseases that are common in the region include malaria, synaptic filariasis, dengue
fever, and Japanese encephalitis. It is predicted that increased temperatures could facilitate the
growth and development of various viruses and insects acting as disease carriers.
Infrastructure, energy and industry would potentially be affected in a number of ways. Storm
surge, extreme tidal flooding and monsoon rains and sea level rise would inundate lowlands,
leading to increasing energy consumption for pumping and drainage. The Delta region contains
many important economic industrial zones and aquaculture areas located in low-lying coastal
areas which could face increased challenges from floods and rising sea level. Climate change
could cause difficulties in water and material supply for industries and construction such as
exploitation and processing of agricultural products, forest product and aquaculture products,
industrial and domestic construction, and communication. More frequent extreme storms,
flooding and salinity would reduce life span of materials, equipment, machines, and buildings,
and maintenance costs would be higher. Sea level rise could affect coastal beaches and thus
tourism; it could also affect cultural and historical heritage and preservation areas (Southern
Institute for Water Resources Planning 2008a,b, c).
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