SLOPE HAZARD AND RISK MAPPING: A TECHNOLOGICAL PERSPECTIVE

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1 International Symposium on Multi-Hazard and Risk March 2015, UTM Kuala Lumpur SLOPE HAZARD AND RISK MAPPING: A TECHNOLOGICAL PERSPECTIVE Very high resolution DTM derived from LiDAR LiDAR Ortho image By: Dato Zakaria Mohamad Project Manager PBRC MINERALS AND GEOSCIENCE DEPARTMENT MALAYSIA MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT MALAYSIA

2 Slope Hazard and Risk Mapping in the Tropics: Why it is a challenging task? In the monsoon-dominated regions, landslides occur in areas characterized by steep hillslopes, high rainfall intensities, seasonally dry periods, unstable slopes and also under forests. Landslide inventory maps are fundamental for assessing landslide susceptibility, hazard, and risk. The compilation of landslide inventory maps is a tedious procedure due to the fact that each individual landslide has to be mapped and described together with their characteristics according to standard practices. Conventional landslide mapping techniques (aerial photos have limitations in a forested mountainous environment >> multi-sensor LIDAR is a promising tool for solving an old geological problem!!

3 RISK ASSESSMENT: CHALLENGES AND ISSUES Gunung Pass, Perak Malaysia Batu Caves, Selangor, Malaysia

4 Current scenarios of landslides in Malaysia Photos of landslides and their impact towards human lives and infrastructure, e.g. road and building are prevailed.

5 Hulu Langat 2010 Bukit Antarabangsa 2008 Highland Tower 1993 Bukit Antarabangsa 2008

6 Sivan Temple 2011 Lebuhraya Mahameru 2014 Bukit Antarabangsa 1999

7 PBRC PROJECT OBJECTIVES To produce slope hazard and risk information in the selected areas for the local authorities in Malaysia for a better slope management. To provide conceptual proposal and cost estimation for mitigating and strengthening high risky slopes. To assist government agencies and local authorities in land-use planning towards a sustainable land management. To develop geospatial infrastructure for national geological terrain and slope information.

8 Landslide Inventory Map For Peninsular Malaysia/East Malaysia (National Slope Master Plan) Kundasang (50 km 2 ) Ipoh (300 km 2 ) Kota Kinabalu (175 km 2 ) Cameron Highlands (400 km 2 ) Bukit Frasers (100 km 2 ) Rawang-Batang Kali (150 km 2 ) Gombak-Kajang- Selayang (300 km 2 ) Cheras Selatan- Bangi (200 km 2 ) Hazard and risk mapping Kapit (100 km 2 ) Landslide prone area

9 PBRC PROJECT AREA IN SELANGOR (650 km 2 )

10 PBRC PROJECT AREA IN CAMERON HIGHLANDS (275 km 2 )

11 PBRC PROJECT AREA IN IPOH (200 km 2 )

12 Conceptual Framework Landslide Hazard and Risk Mapping Airborne LIDAR; 2. Terrestrial LIDAR, 3. GPS Survey, 4. Mobile GIS Field Mapping, 5. Data Processing, 6. LIDAR-Landslide Processing, 7. Landslide Inventory Mapping, 8. Landslide susceptibility Analysis, 9. Landslide Hazard Assessment, 10. Landslide Risk Assessment

13 Methodological Flow Quantitative Landslide Risk Assessment

14 LiDAR Data Acquisition in Klang Valley (Selangor), Cameron Highlands and Ipoh

15 Classified Point Clouds as Ground over Terrain Shaded Relief of very high resolution DTM derived from LiDAR Sample: Klang Valley

16 Classified Point Clouds as Ground over Terrain Shaded Relief of very high esolution DTM derived from LiDAR Ortho image Sample: Klang Valley

17 Bukit Antarabangsa Orthophoto Digital Terrain Model Source: RS GIS

18 Source: RS GIS LiDAR Point Cloud (Cross section), Bukit Antarabangsa

19 LIMESTONE CLIFF MAPPING USING TERRESTRIAL LASER SCANNING, BATU CAVES, SELANGOR MALAYSIA Colorized point cloud derived from TLS LIDAR Stage 1 Planning & Pre-survey Stage 2 Data Collection Stage 3 - Data Processing and Analysis Long range TLS scanner

20 Rock slope characteristics revealed by hyperspatial TLS data (Batu Caves, Selangor). A) Usual geometric terrain of rock slope. B) Peculiar characteristic of natural rocky limestone. C) An entire of cross sections coupled with rock cliff boundary and contour line used for geological and geotechnical assessment.

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22 TLS Ortho Image from the Permatang Kuarza Selangor (Klang Gate Quartz Ridge), Klang Valley Source: GPS Land

23 TLS Ortho Image at Kg. Dumpirin, Kundasang, Sabah Source: GPS Land

24 CONCLUSION 1. Methodological working framework for slope hazard and risk mapping has been developed for PBRC project 2. Multi sensor (airborne and terrestrial) system is a critical tool for providing an accurate geospatial data input (very high resolution DTM and DSM) for landslide hazard and risk assessment in the tropics. 3. PBRC creates a platform for developing a comprehensive landslide inventory using LiDAR technology for regional and national purposes. 4. PBRC promotes multi-disciplinary and knowledge-based approach for complex landslide assessment and disaster risk reduction initiative in Malaysia.

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26 Thank you