Mekong River, the world’s 12th-longest river and the 7th-longest in Asia, plays an important role in the socio-economic development of the countries including China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. In the past 60 years, the Mekong River system from the Tibetan Plateau to the Mekong Delta of Vietnam has suffered a lot of impacts from human economic activities such as the loss of 75% of Yunnan forest and 20% of the Tonle Sap Lake Forest; the growth of hydroelectric dams, pumping stations for agriculture, industry, and livelihood of riparian communities including Yunnan (China), Myanmar, Laos, Thailand, Cambodia, and Vietnam. These activities and other manmade disasters have had serious impacts on climate change and the regime of Mekong River water. And especially the Mekong Delta has been most heavily affected. Therefore, using the Mekong water resources productively in the Mekong Delta region to ensure the national food security and raise farmers’ income sustainably is an urgent need. The article analyzes how the current state of using water resources in the Mekong Delta has brought the efficiency to Vietnam’s socio-economic development in recent years and what should be improved in the context of climate change to meet the above need.
The current situation of Mekong Delta water resources
The Mekong Delta inflow annually receives a large amount of water from upstream and then pours into the sea. However, the Mekong River basin, one of the three major basins in the world, has been seriously threatened by climate change. Also, a vast area in the Mekong Delta, about one-third, will be flooded if the sea level rises by one metre by 2100 according to a forecast. The Mekong Delta depends a lot on the water resources of the Mekong River, thus building hydroelectric dams in the upstream portion has changed the flow regime as well as reduced the amount of silt, causing severe losses to the aquatic products in the Mekong Delta. Especially, as a key resource in aquaculture and agriculture, the Mekong Delta plays a vital role in the country economy, but those changes have caused difficulties for the region’s ecosystem and people’s livelihood and also caused other socio-economic and environmental losses. With too little amount of water from the upstream - Tibetan Plateau, the inflow of the Mekong River, when the ice annually melts, runs through a lot of flows before entering into the Mekong Delta of Vietnam including at least 4 of the 11 major operating hydroelectric dams of Yunnan (China); 2 operating hydroelectric dams and 2 building dams with hundreds of pumping stations on the tributaries of Laos; the arid northeast region of Thailand (where thousands of pumping stations are operating); Cambodia's Tonle Sap region; and finally Vietnam. Its flow began to change greatly after 1978 when the flow measured in Kratie (starting in the downstream of Cambodia and the Mekong Delta) in the rainy season decreased from 77,000 m3/s to 34.000 m3/s. Especially in 2016, during the dry season, the phenomenon of El Niño combined with a sharp decrease in the flow, droughts occurred throughout the Mekong River system (the most heavily influenced regions were in Thailand and Vietnam), and saltwater intrusion took place strongly into the mainland of the Mekong Delta. In late 2016, the phenomenon of La Niña caused rainstorms and flooding in a lot of regions of Philippines, Indonesia, Vietnam, Cambodia, Laos, and Thailand.
Solutions to the sustainable use of the Mekong River water resources
In the situation of the irreversible decrease of freshwater, the essential things we need to do are to change our habits of wasting water resources into using efficiently the water resources and not to make climate change worse. Therefore, in the industry and services sectors, there should be the processes of wastewater treatment for reusing in the industry and personal and environmental hygiene. In saltwater areas, our ancestors knew how to save freshwater efficiently (taking a bath with salt water first, then finishing with a few dippers of freshwater to desalt). In the agriculture sector, we need to appeal to producers and consumers for their knowledge and self-awareness of using freshwater resources efficiently in the context of freshwater scarcity. It is necessary to apply water-saving techniques for rice cultivation so as to improve the yield and quality of rice. The techniques can be applied including alternate irrigation, rotational crops of rice and shrimp, and so on. In areas of saltwater intrusion, we need to abrogate the policy of freshening for rice cultivation, but only grow some specialty varieties of rice in the rainy season, and to switch the areas of unstable rice cultivation into the areas for ecological or intensive farming of shrimp, and shrimp and fish farming in mangroves. In the coming decades, the Mekong Delta will have to deal with the global challenges of climate change and regional challenges of using water resources in the upstream Mekong River. These challenges are going to bring serious impacts on both the economy and the environment in the Mekong Delta. Therefore, we need some basic solutions as follows:
Firstly, we need to innovate the production thinking of farmers: Farmers need to participate actively in the new-type agricultural cooperatives to have the opportunities to learn and implement strictly the new production processes with effective techniques, at least in the following steps: control soils (plough deep and rake carefully with organic composts for better water retaining and efficient nutrients); balance fertilization: basal fertilizing including organic and NPK fertilizers with lime and micronutrients (if needed). This is the most basic techniques for healthy plants to resist many types of harmful pests.
Secondly, we need to reorganize the agricultural production reasonably: cultivating short-day rice with high productivity for the adaptation to the environment, and reforming the structure of crops and livestock suitable for practical production conditions. Particularly in the Mekong Delta, the sowing of rice should be taken place at the non-salinity areas such as An Giang, Dong Thap provinces, but it is necessary to have water-saving solutions. In the freshwater areas, we can still grow rice, fruit trees; in the saltwater or brackish areas, we should switch to the model of rice - shrimp farming…
Thirdly, we have to strengthen international cooperation and exchange to have the in-depth researches which propose solutions for saving and using water resources appropriately and effectively in the Mekong Delta region, including structural solutions and non-structural solutions such as building appropriate irrigation systems for the shrimp – rice farming; implementing land consolidation or land accumulation for planning again irrigation ditches and canals for each model of rice – shrimp farming, ecological farming of shrimp, semi-intensive and intensive farming of shrimp; construct the dyke system and intensively cultivate vegetables in the appropriate places…
People’s Teacher, Prof., Dr. Vo Tong Xuan
The Rector of the Nam Can Tho University.