NATURE OF PROJECT: GEOLOGICAL TERRAIN MAPPING, ENGINEERING GEOLOGY & GEOHAZARDS ASSESSMENT
CLIENT: HECTARE POINT SDN BHD
DURATION: NOV 2018 – MAR 2019
INTRODUCTION
Development on hilly terrain requires a comprehensive geological, engineering geology and geohazards assessment. Geomapping Technology Sdn Bhd undertook this study to assess any geological and geohazards constraint for the proposed development of housing area to fit the requirement for Kebenaran Merancang (KM). Geological Terrain Mapping was conducted based on Guidelines published by Jabatan Mineral dan Geosains (JMG. GP.06). Geohazards assessment established by analyzing and observing the changes on terrain through satellite images and orthophoto. Apart from that, desk study on previous landslide event located at the study area also in consideration. Boreholes data from the previous soil investigation also being analyzed and the soil layer data was tabulated and summarized.
RESULT & DISCUSSION
Geological Terrain Mapping
Figure 1 shows the result of Geological Terrain Mapping divided into Parcel 1 and Parcel 2. These tabulated result shows the percentages of classes from Class I to Class IV based on the terrain mapping campaign that was conducted. Construction Suitability Map (CSM) is the ultimate product of Geological Terrain Mapping as shown in Figure 2.
Figure 1: Result of Geological Terrain Mapping on Parcel 1 and Parcel 2.
Figure 2: Construction Suitability Map of the study area
Geohazards Assessment
There was landslide incident happened in this area on 3rd November 2009. The debris closed the entire three-lane road leading to Rawang from Selayang, with soil covering about 70m of the road and marked as L1 in Figure 3. Recent orthophoto that was captured during the fieldwork shows the evidence of 2009 landslide scar and few other landslide locations within the study area. Old landslide scar and potential landslide was demarcated. Figure 3 shows the potential landslide location based on terrain analysis and temporal satellite images that was analyzed.
Figure 3: Potential landslide location based on terrain analysis and temporal satellite images that was analyzed.
CONCLUSION
Geological Terrain Mapping and geohazards assessment is important for any development planning especially on hilly terrain area.
