نوع مقاله : مقاله تحلیلی
نویسندگان
1 Faculty of Science and Natural resources, Universiti Malaysia Sabah
2 Faculty of Engineering, Universiti, Malaysia Sabah.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The combined approach between Induced Polarizatioan Imaging (IPI), Elecrical Resistivity Imaging (ERI), core sample and the stratigraphic information were carried out at the Klias Forest Reserve, Beaufort, Sabah. The entire area consists of Crocker Formation and Quaternary deposits which consist of large area of peat soil. The main purpose of the geophysical surveys was to characterize the properties of peat and measure the thickness of the peat soil. This include to investigate the peat characterizations changes and correlation with the groudwater level changes. For this purpose, seven (7) geoelectrical survey lines were established which consist of electrical resistivity imaging (ERI) and induced polarization imaging (IPI). The configuration of Schlumberger and Wenner array was applied by adopting 41 electrodes with 1.0m-5.0m of electrode spacing. The survey lines setup provide length of the ERI & IPI survey line varies from 80m- 200m which also provide depth of information of subsurface varies from 15 to 40 from the surface. Three (3) bore hole were produce which located near with the geoelectrical survey lines and core samples were collected at depth of 0-6m for each of the borehole. The resistivity survey lines R1, R2, R3, and R4 were conducted nearby Borehole A. Borehole B was taken alongside the survey line R5. Whereas Borehole C was taken near survey lines R6 and R7. The results of the ERI & IPI surveys show that the subsurface strata are composed of peat materials with resistivity values of 15Ωm – 500 Ωm, clay having resistivity values of 30 Ωm – 60 Ωm and the resistivity value of boundary between peat and marine clay resistivity range from 20 Ωm -80 Ωm. The thickness of the peat and clay obtained ranges from 0-6m and 6-28m respectively. The clay layer is thickening towards the West to the East. While the peat layer shows a varied pattern from West to East. The combined approach between ERI, IPI and core sampling helped to better define the characterization of the material and their thicknesses within the subsurface. Applying ERI and core sampling, were the effective method for characterizing peat physical properties, and thickness estimation. The clay layer is thickening towards the West-East with a thickness of about 6-28m. While the thickness of the peat layer about 0-5.5m shows a varied pattern from West to East. Variety of the thickness pattern from West-East was influenced by the fluctuation water table, moisture content, organic content, cation exchange capacity, bulk density and porosity.
کلیدواژهها [English]
)