Using 2-D Resistivity Imaging in Environmental Problems

2-D resistivity imaging survey was conducted at Gunung Keriang, Kedah. The limestone in the area belongs to the Chuping formation. The interaction in limestone produces karst characteristics such as cavity and pinnacle. These features may threat human's life and damage properties. The objective of the study is to detect cavities, pinnacles, fractures and void that may formed in limestone area by using 2-D resistivity imaging method. Seventeen survey lines were carried out surrounding Gunung Keriang. However, only 2 lines will be discussed in this paper. ABEM SAS 4000 system was used to collect the data. Measurement was made with Pole-dipole array and 5 meter electrode spacing was used. Result from the resistivity image indicates four pinnacles with high resistivity. The air-filled cavity was detected in Line 1 while water-filled cavity was detected in Line 2. The method has been used successfully in detecting cavities and pinnacles.