Types and uses of EG map

An engineering geological map shows geological conditions (lithology, structure, soil, groundwater, hazards) classified according to their influence on engineering works.

Types

1. By purpose:
   • General-purpose maps show basic geology for many uses (regional planning).
   • Special-purpose maps are made for one project (dam, tunnel, road, landslide hazard).
2. By content:
   • Analytical (single-factor) maps show one aspect, e.g. rock type, groundwater, slope, landslide inventory.
   • Comprehensive (complex) maps combine all factors.
   • Zoning (synthesis) maps divide the area into zones of similar engineering suitability.
3. By scale: small (smaller than 1:100,000, regional planning), medium (1:100,000-1:10,000, feasibility), large (1:10,000 and larger, detailed design).

Uses

• Site selection and comparison of alternatives for dams, tunnels, roads, bridges, buildings.
• Planning of site investigation (location of boreholes, trenches).
• Design of foundations, slope cutting and support.
• Hazard and land-use zoning (landslides, floods, earthquakes).
• Locating groundwater and construction materials.
• Estimating cost and construction methods.
• Environmental and urban planning.