During the second half of the 20th Century, Asia South-East was
the arena of a series of armed conflicts, direct consequences of
the Second World War, decolonization and the Cold War, followed
by political instability which continued up to the 1990s. The
region’s history has left its scars: extensive forests razed
from the map by bombing, populations displaced or obliged to
emigrate, entire areas abandoned although vegetation is steadily
taking over again . Research scientists from the IRD and its
partners( 1) recently showed the discharge rate of the Mekong
has oscillated in close correlation with the major events that
had taken place. Runoff increased by over 50% in southern Laos
between 1972 and 1975, at the height of the Vietnam War.
Conversely, the north of the country saw it decrease by 30%
between 1995 and 2004, following people’s exodus from the area
to escape from the communist forces’ advance. Only the extensive
changes in land-use and vegetation pattern can explain such
variations in discharge of t