| Abstract | A series of thematic maps for the town of Khorat were constructed .
They are geomorphological map, geologic map, engineering geologic map,
hydrogeologic map and fence diagram, urban mineral resource map,
geotechnical land use limitation map, physical constraint map, slope
map and documentation map. The landform features of the Khorat city
is comprised of undulated terrain, undifferentiated terrain, alluvial
terrace, oxbow lakes, and swamp, flood plain, stream and tributaries. The
Khorat area is underlain by rocks of the Khok Kruat, Mahasarakam and Phu
Khao Thong Formations and unconsolidated sediments which consist of
gravel bed, laterite, alluvium and loess. The surficial geology consist
of loess, alluvium and land fill deposits. The loess is sandy silt (ML)
and silty sand(SM). It is non dispersive. The alluvium commonly consists
of sandy clay(CL), silty clay (CL), clayey sand (SC) and silty sand with
clay(SM). The land fill are composed of loessial soil , alluvium, laterite,
gravel and solid waste refuse. An alluvial aquifer yield good quality
water inlarge quantity. Shale is the bed rock of the area . Its depth is
about 20-60 m below the ground surface. Construction materials are adequate for us e up to the year 2001. The city has inadequate waste
disposal site, shortage of water supply and no proper plan of the urban
built up area. Flooding is caused by overflow and poor drainage along
the old alluvial terrace and the Lumtakhong area. However,
groundwater is plentiful in that particular zone. |