Climate change and challenges of the delta of Mekong River.
I would like to discuss some challenges of the climate change impact on the Mekong river delta, in the South of Vietnam. It is located about 100 km from the sea, and its altitude is at about -1 meter below the sea level. That means that the region is subject to floods and also that salty water from the sea penetrates the river. The whole Mekong delta, to which the city belongs with Saigon River, is exposed to the factor of flooding and salinisation of water, which are two climate-related processes I would like to explore.
The Mekong river basin area is about 795,000 km2. It is home to 18 million people or 22% of the national population, and produces 54% of Vietnamese rice production and almost all the rice for exports (Konishi). Note that Vietnam is now the second world rice exporter.
Sea level rise by 1m would cause severe inundation: about 40,000 km2 will be flooded annually. Over 14 million people will be subject to annual flooding in the Mekong delta provinces (Unep). In the city where I live, the water increase level will cause floods and it will require raising the level of roads and houses.
Illustration: in blue the areas which will be inundated by a sea level rise by 1 meter (source: Challenge to Change)
According to The Guardian (The Guardian), Vietnam one of the most exposed countries to the sea level rise. According to this report, only the Bahamas are more vulnerable to a one-metre rise in sea levels.
The sea level rise in Vietnam due to the global climate change are documented in (Konishi): the actual rise, by now, is already 12 cm and is expected to reach 33 cm by 2050 and 45 cm by 2070.
The second factor is salinisation. When air temperature increases by 1 degree C, the potential evaporation would increase by 3%. This amplifies the impact of the sea salty water inflow on the agriculture. When the sea water rises by 1 meter in Mekong Delta, the area to be suffered from the salinity would be 1.6 million hectares (VNN).
Illustration: salinity intrusion line (source: Konishi).
In the Ben Tre province, now we experience the "salty seasons", when the water in the river becomes unusable for crops and drinking. People remember, that before there was no salty season at all, now it lasts about 5 months a year. According to Ben Tre's government, the area where the salt content is above 4ppt (parts per thousand), is about 35 km inland already. This salinity intrusion is a secondary effect of the climate change, as it links directly to more sea salty water coming upstream of Mekong, as a result of global sea level increase.
Bibliography and references:
1. Unep: Unep/gef project "Viet Nam: Expedited financing for measures for capacity building in priority areas (Phase II)". Technical report on the identification and assessment of technology needs for GHG emission reduction and climate change adaptation in Viet Nam. Ha Noi, 2005.
2. VNN: Vietnam’s rice productivity may reduce 10% on climate change. VNN, September 2013. http://news.com.vn/science-and-education/environment/120792-vietnams-rice-productivity-may-reduce-10-on-climate-change.html
3. Konishi: Climate Change on the Vietnam, Mekong DeltaExpected impacts and adaptations. Toru Konishi. World Bank. East Asia Infrastructure.
4. Challenge to Change: https://www.challengetochange.org/climate.htm
5. The Guardian: http://www.theguardian.com/environment/2011/aug/21/vietnam-rice-bowl-threatened-rising-seas
The Mekong river basin area is about 795,000 km2. It is home to 18 million people or 22% of the national population, and produces 54% of Vietnamese rice production and almost all the rice for exports (Konishi). Note that Vietnam is now the second world rice exporter.
Sea level rise by 1m would cause severe inundation: about 40,000 km2 will be flooded annually. Over 14 million people will be subject to annual flooding in the Mekong delta provinces (Unep). In the city where I live, the water increase level will cause floods and it will require raising the level of roads and houses.
Illustration: in blue the areas which will be inundated by a sea level rise by 1 meter (source: Challenge to Change)
According to The Guardian (The Guardian), Vietnam one of the most exposed countries to the sea level rise. According to this report, only the Bahamas are more vulnerable to a one-metre rise in sea levels.
The sea level rise in Vietnam due to the global climate change are documented in (Konishi): the actual rise, by now, is already 12 cm and is expected to reach 33 cm by 2050 and 45 cm by 2070.
The second factor is salinisation. When air temperature increases by 1 degree C, the potential evaporation would increase by 3%. This amplifies the impact of the sea salty water inflow on the agriculture. When the sea water rises by 1 meter in Mekong Delta, the area to be suffered from the salinity would be 1.6 million hectares (VNN).
Illustration: salinity intrusion line (source: Konishi).
In the Ben Tre province, now we experience the "salty seasons", when the water in the river becomes unusable for crops and drinking. People remember, that before there was no salty season at all, now it lasts about 5 months a year. According to Ben Tre's government, the area where the salt content is above 4ppt (parts per thousand), is about 35 km inland already. This salinity intrusion is a secondary effect of the climate change, as it links directly to more sea salty water coming upstream of Mekong, as a result of global sea level increase.
Bibliography and references:
1. Unep: Unep/gef project "Viet Nam: Expedited financing for measures for capacity building in priority areas (Phase II)". Technical report on the identification and assessment of technology needs for GHG emission reduction and climate change adaptation in Viet Nam. Ha Noi, 2005.
2. VNN: Vietnam’s rice productivity may reduce 10% on climate change. VNN, September 2013. http://news.com.vn/science-and-education/environment/120792-vietnams-rice-productivity-may-reduce-10-on-climate-change.html
3. Konishi: Climate Change on the Vietnam, Mekong DeltaExpected impacts and adaptations. Toru Konishi. World Bank. East Asia Infrastructure.
4. Challenge to Change: https://www.challengetochange.org/climate.htm
5. The Guardian: http://www.theguardian.com/environment/2011/aug/21/vietnam-rice-bowl-threatened-rising-seas