Potential soil characteristics for riverbank filtration using 2-D ground resistivity in Kota Lama Kiri, Kuala Kangsar
Identifying the subsurface profile for riverbank/bed filtration (RBF) using conventional methods such as drilled boreholes is usually labor intensive, costly and acquires only 1-D profiling. Hence, a 2-D ground resistivity method was used as an alternative to obtain a 2-D subsurface profile by extending to 200 m length at Kota Lama Kiri, Kuala Kangsar, Perak site area. Four resistivity survey lines (200 m each) with minimum electrode spacing of 5 m were executed at the site area. The Wenner-Schlumberger array protocol was applied for acquisition data process. The resistivity data were then processed and interpreted using RES2DINV software. The results show the approximate 2-D pseudo-section image of the subsurface resistivity distribution with different soil types. The interpretation of results reveals that the site area consists of two main layers: (a) sand and gravel (300–750 Ωm) from 0 to 10 m depth, and (b) weathered rock (0–350 Ωm) within 10 to 40 m depth. It found that the first layer (0–10 m depth) belongs to the alluvial aquifer type and has a relatively high permeability, thus suitable for RBF. This method is believed to be able to give great assistance for selecting the suitable area for RBF in the future.