A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Sc.) - Asian Institute of Technology, 1987

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.