Abstract:
A steady state, two-dimensional vertical section groundwater
flow model has been developed for a salinised area
of the Xe Champhone catchment in Savannakhet province,
Southern Lao PDR. The area is underlain by
evaporite beds and clastic sedimentary rocks of the Khorat
Group that are the source of salt found in groundwater and
surface soils. The Xe Champhone catchment is of interest
because of plans for construction of several new reservoirs
and extensive expansion of irrigated areas. This
study provides an example of how a relatively sparse and
limited data set has been used to construct and successfully
calibrate a numerical flow model to investigate
groundwater flow patterns and potential impacts of increased
groundwater recharge on land salinisation. Results
show the predominance of local flow systems and
that deeper flow systems in contact with the rock salt
layer operate over much longer time scales in the order of
millions of years.
