Contemporary hydrological alterations in the Lower Mekong

Major efforts have been invested in simulating the expected future changes in the hydrology of the Mekong. However, we know little about contemporary changes that the basin has experienced in recent decades. Works by Delgado et al. (2012) and Räsänen et al. (2013) revealed a great deal of changes in the frequency and magnitude of floods, but little has been shown with regards to seasonal hydrological parameters that could have been influenced by water infrastructure development. Using water level records for different stations downstream of Chiang Sean and the Impact of Hydrological Alterations Tool we have been able to show that since 1991:


  • Significant changes in water levels during the dry season and water level fluctuations have happened.
  • These hydrological parameters are mainly influenced by water regulation (aka., water resources development).
  • water resources development in the tributaries is also a key driver of change.



















































 flow fluctuations upper basin

Fluctuations - lower basin

 Associated journal publication:

Cochrane, T. A., Arias, M. E., Piman, T. (2014) Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap System. Hydrological and Earth System Sciences Discussion 11, 4403-4431. DOI: 10.5194/hessd-11-4403-2014.