Investigation of The Mekong’s Riverbanks and Social Preferences Towards the River Dam Projects

Abstract

In recent years, the construction of several mainstream hydropower dams along the Mekong River has caused significant fluctuations in water levels, resulting in adverse effects on the stability of riverbanks and local customs and lifestyles in Thailand. This study aims to investigate the physical condition of the riverbanks and the social preferences of local people towards the levees and mainstream dams along the river. The Global Positioning System (GPS) receivers coupled with satellite imagery are employed to identify the locations of levees; riverbanks; and levees failures. The findings present that 430.38 km levees of the total 985 km riverbank (about 45%) were built, along which 3 positions collapsed. The longest failure is in Wiang Kaen district in Chiang Rai, with a length of 320 m. Along the riverbanks with no levee protection, 1 positions collapsed with the longest length of 1.4 km found in Ban Phaeng district in Nakhon Phanom. Furthermore, the results from 300 questionnaires reveal that about 61% of respondents are farmers and fishers, and 70% of the total have lived in the area for more than 10 years. The majority (more than 80%) are satisfied, at the highest level, with constructed levees; however, they are dissatisfied, at the high level, with mainstream dams due to negative impacts currently affecting their lives. Benefits of constructing an embankment to prevent slope erosion extend beyond safeguarding against the loss of land caused by the collapse of slopes resulting from water erosion. It also instills a sense of security among the residents in the area regarding the safety of their homes along the Mekong River embankment, ultimately leading to an increase in land value.