ABSTRACT
The most extensive area of the Northeast Thailand is underlain by a thick sequence of Mesozoic rocks which
contain considerable quantities of rock salts (Maha Sarakham Formation).The occurrence of this Formation leads to
soil salinization scattered throughout the regions. The salinization has the profound effects on the crop production
and consequently on the regional economy. The soil salinity potential in the region was then established with
objective of providing a spatial distribution of severity classes of soil salinity. Based on the sources and
mechanisms regarding salt-affected areas, the creation of GIS data layers was then performed to be used for overlay
modeling with defined criteria. The data layers include geologic formation, ground water quality and its yield, land
cover and land form. These layers consist of a set of logically related geographic features and its associate
attributes. The overlay operation was then undertaken with criteria that the severity of salinity, based on the salinity
model applied to the resultant polygonal layer or salinity class. The salinity classes were randomly checked against
the salt crust map performed by the Land Development Department. The areas of soil salinity potential cover 0.66,
8.93, 9.81 and 88.60% of the total area for high, moderate, low and none salinity respectively.