More than half of the 4 million hectares of the Mekong Delta are covered by acid sulfate soils (ASS). Most ASS areas have been reclaimed for agricultural production during recent decades by means of new canals, new settlements, floodplain drainage, and new rice varieties and cropping systems. In 1996, agriculture occupied 83% of the total area of the Delta. Urban areas account for 10% of the total area. This leaves only 7% for natural or semi-natural wetlands. Rice is the dominant agricultural product and greatly contributes to the food security of the country. Rice exports have increased at an average rate of 4.6% per year (1990-1996), accounting for 15% of the national export earnings. Digging canals and drainage to remove acidity are prerequisites for reclaiming ASS for agriculture, but may create environmental problems such as soil acidification, acid water pollution and loss of functioning wetland ecosystems. The difficulties of farming on ASS and the unpredictable agricultural market often force farmers to sell their land, and many landless people are compelled by poverty to exploit the already diminished natural wetlands. This leads to further environmental degaradation, pressure on natural ecosystems, and further poverty. In the future, strategies for sustainable development of the Mekong Delta should be based on balancing agricultural development and natural wetland ecosystem management.
Status of the Mekong Delta: agricultural development, environmental pollution and farmer differentiation
Ni, D.V., Maltby, E., Stafford, R., Tuong, T.P., Xuan, V.T. (2003)
Wetlands management in Vietnam: issues and perspectives