Prior to construction and infrastructure projects it may be necessary to characterise landscape features to assess their suitability for design purposes.
These may include depth of drift cover to bedrock, body of water profiling and sediment thickness, extent of sink hole formation.
Resistivity imaging if often employed due to its ability to penetrate up to depths of 30m+.
The resistivity imaging technique employs a line of metal stakes (electrodes) temporarily inserted in the topsoil through which electrical current is made to flow. Different materials have different resistances which are linked to moisture content, and therefore porosity. Hard, dense features such as rock will give a relatively high resistance while features such as a ditch, which retain moisture, give a relatively low response. This means that bedrock, fissures ad other geological trends can be mapped.