Geological Terrain Mapping Report

GEOLOGICAL TERRAIN MAPPING REPORT

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan

APRIL 2019 Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

(1) PROJECT INTRODUCTION

This report generally presents the results for geological information assessment for the project of "Proposed Logging Project on Block A, Block B, Block C and Block D With An Area of 417,000 Hectares (1,3030.43 Acres) At Mukim Kenering, Daerah Hulu Perak, Perak Darul Ridzuan”. This report is submitted as part of the requirements by Department of Environment Malaysia (DOE).

(2) SCOPE OF STUDY

The scopes of this study are as follows: a) To map the surface geology, including rock type (if any), geological structures and weathering grades. b) To assess the hydrogeology condition and potential geohazards. c) To study and classify the geomorphology and surface terrain features.

(3) METHODOLOGY

The following procedures are adopted for the preparation of this report: a) Conducted reconnaissance survey to assess the following:

i) Accessibility of the site

ii) General morphology of the area

b) Study the aerial photograph or satellite imagery to locate areas of instability to include:

i) Recent and relict landslide scars

ii) Areas with soil creep

iii) Land clearing activities and vegetation cover

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

c) Base map of 1:1000 scale with the site reference to Ordinance Survey datum as shown in the survey drawing. d) A slope gradient map of the area is prepared from the topographical survey plan with the use of a digital terrain modeling computer software called "ArcGIS".

(4) REVIEW OF PROJECT BACKGROUND

4.1 Site Location The proposed site is located Mukim Kenering, Daerah Hulu Perak, Perak Darul Ridzuan. The main access to the proposed development is through Jalan Baling – Kuala Kangsar.

Proposed Development Area

Figure 1: Site location of the proposed development area

4.2 Topography and Existing Site Condition The proposed site is situated on a natural hilly terrain mostly covered with trees. Based on the topography survey plan as shown in Figure 3, the highest ground of the site is about 500m from the sea level, which is located at the middle whilst the lowest ground is about 320m from sea level located at northwest and southwest part of the site. The maximum difference in

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan. elevation of the topographical highs and lows (relief) of the site for the proposed development is approximately 180m, indicates the project site has generally moderate to steep slope profile. The distance from northern boundary to southern boundary is about 4400m whilst from the western boundary to eastern boundary, the distance is about 1200m.

4.3 Aerial Photograph Aerial photograph using Google Earth is adopted to have a better view of the project site. It is observed that most of the areas within the project site are primary forest with dense trees.

4.4 Regional Geology Based on published Geology of Peninsular Malaysia, published in 2009 by University of Malaya and the Geological Society of Malaysia, the site is underlain by the North Perak Paleozoic Formation.

Lower Paleozoic rocks are confined to the western part of the peninsula, and Upper Paleozoic rocks are found in all three belts in the tripartite peninsular divisions (Western Belt, Central Belt, and Eastern Belt of Penisular Malaysia). The most complete sequence of Paleozoic sedimentary rocks, ranging in age from Upper Cambrian to Upper Permian, is exposed in the Northwestern Domain of the Western Belt, in Langkawi, Kedah and Perlis. These are mainly shallow-marine shelf sediments of the Machinchang and Jerai Formations, Setul group, Timah Tasoh and Chepor Formations, Singa and Kubang Pasu Formations and Chuping Limestone.

Palaeozoic rocks of the rest of the Western Belt are distributed in the foothills along both flanks of the Main Range granite batholith stretching from Malaysian-Thai border southwards to Malacca. On the western side of the Main Range is the Baling Group sediments consisting of the Papulut Quartzite, Grik Siltstone, Lawin Tuff and Bendang Riang Formation in north Perak.

The Upper Ordovician to Lower Devonian Kroh Formation, described by Burton (1986) was named after the town called Keroh that have been renamed to Pengkalan Hulu. It has a conformable lower contact with the Papulut Quarzite and consists of black carbonaceous shale and siliceous mudstone with chert. Lawin Tuff, a volcanic equivalent of the Grik

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan. formation, is included in the Baling Group. It is an acid rhyolitic crystal stuff of Ordovician to Early Silurian age. The volcanic rocks are interbedded with and pass imperceptibly into quartzite, shale and thin limestone of the Baling Group in the south and east of Grik. Lithologically, the area is underlain by granitic rocks.

Figure 2: Geological map of project site

(5) SURFACE ENGINEERING GEOLOGY

5.1 Weathering Profile Weathering profile is characterized by lateral and vertical variations in the degree of preservation of the minerals, texture and structure of the original bedrock. These variations allow for recognition of the morphological zones and horizons that can be correlated with rock mass weathering grades.

The parent rocks under tropical climate conditions normally surfer severe chemical weathering, producing a thick residual soil of various consistencies weathering zones are developed approximately parallel to overlying ground surfaces and thicker below the ridge

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan. crest and summits, but thin towards valley floor except for the case of areas with colluviums deposit. The varying weathering thickness is dependent upon several factors including the mineralogy and texture of the original bedrock, the regional and local topographic settings as well as site geomorphic history.

In general, the weathering profile can be categorized into 6 grades (Grade I to VI) as elaborated in Table 1. Based on the site mapping, the site area covered by moderately weathered (Grade III) and residual soil (Grade VI) of mostly yellowish orange mottled with brown in colour with some gravel.

5.2 Hydrogeology The site is generally dry without water seepage due to natural steep hilly terrain. Outside the southern boundary, there is existing river named Sungai Perak.

(6) GEOLOGICAL TERRAIN MAPPING

The Jabatan Mineral and Geosains Malaysia has introduced a terrain mapping program which was a modified version of the same system practiced in Hong Kong. Information and example on the application of terrain mapping in Malaysia were presented by Chow and

Mohamad (2002) and Mohamad and Chow (2003).

Terrain classification is carried out based on four attributes (Table 2), that is the:

i) Slope gradient,

ii) The terrain or morphology,

iii) The activity and,

iv) The erosion and instability.

Based on these four attributes, polygons are defined, reflecting on the steepness of the terrain, the morphology of the slope, the activities that are conducted on the slope and the degree of erosion or instability on that slope. Such definition of polygons is best conducted in the field.

However, in areas which are inaccessible, recent aerial photographs may be used.

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan. The polygons in the Terrain Classification Maps are digitized and analysis is carried out with a GIS program (Arc View) producing the various thematic maps as follows:

6.1 Slope Map The map summarizes the broad terrain pattern in the map sheet where slope angle and terrain attributes are delineated. This map is designed for the use of technical and non-technical users who require general landform data for planning purposes. The Slope Map is presented as Drawing 1.

Based on slope map, the slope gradient can be classified. Generally, the area consists of very gentle slopes (0°-15°), gentle slopes (15° - 25° ), moderate steep slopes (25°-35°) and steep slopes (>35°). Most of the slope has varies gradient as shown in Slope map (Drawing 1).

Slope Gradient Class Area (Acres) Area (%) 0° - 15° I 140.30 33.64 15° - 25° II 172.38 41.33 25° - 35° III 94.19 22.58 > 35° IV 10.22 2.45

6.2 Erosion Map The Erosion Map is developed from the erosion and instability attributes of terrain classification map. The map delineates the broad pattern of erosion and instability, and is design for technical and non-technical users who require information regarding general nature, degree and intensity of erosion and instability for planning and engineering purposes.

The erosion map is presented as Drawing 3.

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan. (7) POTENTIAL GEOHAZARDS

The landslide assessment system developed by Jabatan Mineral & Geosains (JMG) is mainly at medium scale, and uses Qualitative Map Combination method of assessment. Chow &

Mohamad (2002) describe the use of terrain analysis and classification maps by JMG, which are based on four attributes: slope gradient, morphology, activity and erosion & instability.

Derivative maps are then prepared using a GIS (Arc Info or TIN software). The various map themes produced are landform, erosion, physical constrains, engineering geology and land use suitability. Landslide hazard maps are then created after the vegetation cover and seepage is studied. The classification of hazard and the hazard score used by JMG is shown in Table

Landslide risk scores are then calculated using the standard equation (Risk = Hazard x

Consequence). The consequence and risk scores suggested by Chow & Mohamad (2002) are shown in Table 6 and 7. From this study, we refer to Table 8 to calculate the Risk Rating. The

Geohazard Map is presented as in Drawing 3.

The Geohazard Map shows that the landslide risk score of the project area is less than 25°, which is between Low Risk to Moderate Risk. About 74.97% of the project area located in

Low Risk Zone, 22.58% located in Moderate Risk Zone and 2.45% located in Very High

Risk Zone. The summary of landslide risk is presented as follow:

RATING TOTAL SCORE PERCENTAGE (%)

LOW risk <12.5 74.97

MODERATE risk 12.5-25.0 22.58

HIGH risk 26.0-35.0 0.00

VERY HIGH risk >35.0 2.45

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

(8) CONCLUSION & RECOMMENDATION

Based on the above mentioned findings, it can be concluded that:

a) The proposed site is situated on moderate to steep hilly terrain.

b) Slope analysis conducted in the development shows that considerable land areas are under Class I and Class II categories.

c) In most areas, no erosion has been observed at the proposed site.

d) The potential geohazard risk rating of the project area is between low risks (74.97%) to moderate risks (22.58%)

e) It is recommended that detailed site investigation be carried out for the proposed site for more understanding the subsurface soil condition and to determine the depth of bedrock as well as to obtain the engineering parameters of soil for geotechnical design stage.

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

Table 1: Classification of weathered rock for engineering purposes (modified from Attewell,1993)

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

TerrainClassification and landusehazards zonation attributes(Jabatan Mineral danGeosains, 2005)

: 2

Table

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

Construction SuitabilityClassification System Table (after JMG. 7, GP. 06)

Table

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

Landuse classes type and of site investigationrequired (after Mohamad Chow, & 2003)

Table

Table 5: Classification of landslide hazards rating used by the JMG (Chow & Mohamad, 2002)

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim

Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

Topography SurveyPlan

Figure

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

Plate 1: Aerial view of project site

Plate 2: Access road to site

Proposed Logging project On Block A, Block B and Block C with An Area Of 417.00 Hectares (1,030.43 Acres) At Mukim Kenering, Daerah Hulu Perak,Perak Darul Ridzuan.

REFERENCES

Burton, C. K. 1986. The Baling Group/Bannang Sata Group of the Malay/Thai Peninsula.

Journal of South East Asian Earth Science, 2, 93-106

Chow, W. S. and Mohamad, Z., 2002, Terrain Mapping for Landuse Planning, Second IKRAM

International Geotechnical Conference (IGEO-2), 28-29 Oct 2002, Kuala Lumpur

Mohamad, Z. and Chow, W. S., 2003, Geological Terrain Mapping in Cameron Highlands

District, Pahang, Annual Geological Conference 2003, Kuching, Sarawak, Bulletin of the

Geological Society of Malaysia No. 46, Special Conference Issue.