Impacts of climate change on Mekong Delta
Climate change has been posing a greater flooding threat to the Mekong Delta as a result of rising sea levels near low lying land at the mouth of the delta and increased rainfall. Among the climate change impacts experienced to-date, the Mekong Delta has experienced a 30% annual increase in rainfall, shifting rainfall patterns, an average temperature increase of 0.5 oC over the last 30 years, and an average sea level rise of 3 mm per year over the last 30 years. The average elevation of the Mekong Delta is about five feet above sea level, which makes it particularly vulnerable to sea level rise. Moreover, the impacts of climate change are predicted to be more severe in coming years, with projected increases in average temperatures of 1.1 oC to 3.6oC as compared to Vietnam’s average temperature during the 1980‐1999 period. The average level of Vietnam’s seas is predicted to rise by 28‐33 cm by 2050 and by 65‐100 cm by 2100 as compared to the 1980‐1999 period. As a result, over the next century, “the maximum flow of the Mekong is estimated to increase significantly, while the minimum monthly flows are estimated to decline, meaning increased flooding risks during wet season and an increased possibility of water shortage in dry season”.
Thus, the projected impacts of climate change present a real threat to the agricultural productivity of the Mekong Delta, which will negatively impact the livelihoods of many of its residents due to the importance of agriculture to this region. According to climate change scenarios, 90% of the agricultural land in the Mekong Delta would be affected by flooding and 70% of the Mekong Delta will suffer from saline intrusion as a result of climate change. The combined impacts of flooding and increased saltwater intrusion threaten the agricultural output of the Mekong Delta, particularly its rice production. Accordingly, the rice yield potential of the Mekong Delta will decline by up to 50% by the year 2100, which threatens the food security of Vietnam as well as the numerous countries that rely on its rice exports. Shifting rainfall patterns resulting from climate change will contribute to the predicted decrease in the Mekong Delta’s rice production.
A large portion of the Mekong Delta could become uninhabitable as well if the sea level rises substantially around the low-lying lands at the mouth of the delta. According to MONRE climate change scanarios, 25% of Can Tho province and 50% of Ben Tre province would be completely inundated with water if the average sea level rises by one meter during this century while about 38% of the Mekong Delta’s entire current land area would be inundated. As a result, by 2050, more than 1 million people in the Delta will be directly affected by increased coastal erosion and land loss, primarily caused by sea level rise. Under sea level rise scenarios of 20 cm and 45 cm, permanent inundation would shift inland up to 25 km and 50 km respectively.
Factors affecting the migration decision
According to a recent research by van der Geest et al. (2014) about reasons for migration in Mekong Delta in Vietnam people in poor and very poor households indicated more often that unemployment, lack of income and landlessness were important reasons to migrate (see Figure ).
The prime causes of migration among poorer households are indirectly related to climate variability. Changing rainfall patterns and extreme weather have a negative impact on people’s sources of food and income as a result of the decreased agricultural output in the Mekong Delta. These factors, in turn, are important drivers of migration, especially for poor and land-scarce households. Some researchers underline in their framework for understanding the effect of environmental change on migration, environmental factors tend to influence migration indirectly, mostly through economic drivers. Thus, climate variability affects local livelihoods and the prime reasons to migrate are related to lack of livelihood security or low living standards at home.
In order to reduce negative impacts of migration on socio-economic development and improve well-being of migrants in Mekong Delta, the following recommendations should be considered:
- It is necessary to develop a national survey on migration in Vietnam. The survey has been conducted in other countries also severely affected by climate change. Such a survey can provide detailed information and variables not covered by the census data, including the influence of household need to collect information on movement to and from urban to assess trends of migration over time.
- There is also a need for raising people awareness of climate change and adaptation, as well as understanding of vulnerability. Although a community may be exposed to the same environmental stressor, the differential vulnerability of varying groups to environmental and other stressors is of central importance when designing relocation programs.
- To deal with the number of people who are already at risk of climate change, re-allocate programs should be carried out to move people in the disaster-prone areas to safer areas.
- Apply new technologies and biotic advantage should be applied in for farming to adapt with changes in weather and climate.
- It is necessary to support long-term livelihood outcomes for migrants. After people are relocated, support programs should be implemented to improve the immediate and long-term livelihood outcomes of migrants. Moreover, policies also should ensure their effective access to basic social services and the protection of their rights. This is especially important for low-income migrants in urban centres, for single migrant women (who often face difficulties and discrimination in destination areas).
- Government policies should support more balanced and equitable regional development through public investment in infrastructure in both rural and urban areas. The government also needs to create opportunities for investment in the agricultural sector and the rural economy in Mekong Delta. These measures will simultaneously increase opportunities of non-farm jobs reduce the pressure infrastructure and services in the large cities.
In summary, Climate change is likely has several impacts on population distribution and migration in Mekong Delta in Vietnam. The livelihood, inhabitant status and farming production of the people in this area are vulnerable under the context of climate change. In the face of climate change stress, people in the Mekong Delta will adapt in various ways in which migration is seen as a type of coping mechanism. Moreover, landless and land-scarce households in the study area are most affected by climate change are also most likely to migrate. Thus, livelihood stress is the direct cause for migration and environmental factors act as the trigger. Moreover, climate change will be more severe in the future and number of affected people continues to increase. Therefore, it is necessary to integrate climate change related factors in local and national policies on migration to have appropriate interventions that aim to help climate change migrants improve their adaptive capacities and their livelihoods.