Kemudahterancaman bencana gelinciran tanah (LHV): Sorotan literatur dan cadangan pendekatan baru untuk pengurusan risiko gelinciran tanah di Malaysia


Author : Rodeano Roslee & Tajul AnuarJamaluddinPublication : Bulletin of the Geological Society of MalaysiaVolume : 58Page : 75 - 88Year : 2012DOI : 10.7186/bgsm58201212


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Bulletin of the Geological Society of Malaysia, Volume 58, December 2012, pp. 75 – 88

Kemudahterancaman bencana gelinciran tanah (LHV): Sorotan literatur dan cadangan pendekatan baru untuk pengurusan risiko gelinciran tanah di Malaysia

Rodeano Roslee1,2* & Tajul AnuarJamaluddin1

1Southeast Asia Disaster Prevention Research Institute (SEADPRI),Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor
2 Program Geologi, Sekolah Sains dan Teknologi, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah
*Email address: rodeano@ums.edu.my 

Abstrak: Topik berkenaan kemudahterancaman bencana gelinciran tanah (LHV) masih dianggap baru dan kurang mendapat perhatian di kalangan geosaintis dan jurutera di Malaysia. Kemudahterancaman ditakrifkan sebagai darjah kerugian (kerosakan) bagi sesuatu elemen atau elemen-elemen yang berisiko akibat berlakunya fenomena semulajadi yang bertindak balas pada suatu magnitud tertentu. Walaupun terdapat beberapa garis panduan dan polisi berkenaan pembangunan di kawasan berbukit bagi mengatasi gelinciran tanah, namun bilangan bencana gelinciran tanah di seluruh negara yang membawa kepada malapetaka semakin terus meningkat. Kertas penyelidikan ini cuba mengupas dan merumus konsep LHV dengan mengambilkira pendekatan aspek sosio-ekonomi dan sains. Pendekatan baru dalam konsep kemudahterancaman bagi penyelidikan pengurusan risiko bencana gelinciran tanah (LRM) di Malaysia juga turut diperkenalkan. Untuk merealisasikan matlamat ini, suatu rangka kerja telah direkabentuk untuk menaksirkan LHV. Rangka kerja ini dirumuskan secara semi-kuantitatif melalui pembangunan pengkalan data elemen-elemen berisiko (manusia & harta benda) yang berdasarkan kepada maklumat daripada data sekunder, sorotan literatur yang ekstensif dan pencerapan lapangan. Antara parameter-parameter kemudahterancaman yang diambilkira dalam menaksir LHV termasuklah 1) implikasi fizikal (struktur bangunan, kelengkapan dalaman, kerosakan harta benda, kemudahan infrastruktur dan tindakan penstabilan), 2) status sosial (kecederaan, kematian, keselamatan, kehilangan tempat tinggal dan kesedaran awam), dan 3) gangguan terhadap persekitaran (masa terjejas, operasi harian dan diversiti). Setiap parameter yang diambilkira dalam penaksiran kemudahterancaman diperuntukkan nilai indeks tertentu yang berjulat dari 0 (0 % kerosakan/mangsa/ jangka masa), 0.25 (1-25 % kerosakan/mangsa/ jangka masa), 0.50 (26-50 % kerosakan/mangsa/ jangka masa), 0.75 (51-75 % kerosakan/mangsa/jangka masa) hingga 1.00 (75-100 % kerosakan/mangsa/ jangka masa). Kesemua data hasil pencerapan LHV dianalisis semula berdasarkan kepada kaedah pemiawaian untuk menilai kepentingannya supaya dapat diterima dalam model penyelidikan pengurusan risiko gelinciran tanah (LRM) yang praktikal bagi keperluan keadaan tempatan. Langkah selanjutnya adalah mengira dan menetapkan nilai indeks bagi setiap parameter kemudahterancaman yang ideal. Akhir sekali, jumlah nilai indeks purata bagi ketiga-tiga jenis kemudahterancaman fizikal, sosial dan persekitaran dikelaskan kepada lima kelas darjah kemudahterancaman, iaitu kelas 1 (< 0.20) (kemudahterancaman sangat rendah), kelas 2 (0.21-0.40) (kemudahterancaman rendah), kelas 3 (0.41-0.60) (kemudahterancaman sederhana), kelas 4 (0.61-0.80) (kemudahterancaman tinggi) dan kelas 5 (> 0.81) (kemudahterancaman sangat tinggi). Hasil kajian ini mendapati bahawa nilai indeks LHV di Malaysia adalah jauh lebih tinggi berbanding dengan negara-negara maju. Hal ini antara lainnya disebabkan oleh kurangnya kesedaran awam, pengetahuan dan pendedahan mengenai gelinciran tanah; serta kekurangan kod-kod bangunan dan ketiadaan penilaian rekabentuk kejuruteraan yang mengambil kira faktor-faktor pencetus bencana (hujan lebat/gempa bumi). Perkiraan nilai indeks kemudahterancaman tidak dapat ditentukan secara kuantitatif.

Landslide hazard vulnerability (LHV): Review of literature and a proposed new approach in landslide risk management for Malaysia

Abstract: Topic on landslide hazard vulnerability (LHV) in Malaysia is relatively new and received little attention from geoscientists and engineers. Vulnerability is defined as the potential degree of loss (damage) to a given element or risk elements resulting from the occurrence of a natural phenomenon of a given magnitude. Although there are some guidelines and policies regarding hillside development to prevent landslide, the number of disastrous landslide events is steadily increases nationwide. This paper reviews and formulates the concept of LHV by taking into account the socio-economic and science aspects. New approach in vulnerability concept in landslide risk management (LRM) in Malaysia is also introduced. To achieve this goal, a framework was designed for assessing the LHV. The framework was formulated semi-quantitatively through the development of a database for the risk elements (human & properties) based on secondary data, review of literature and field observations. The vulnerability parameters include in assessing LHV are 1) physical implication (building structures, internal materials, property damage, infrastructural facilities and stabilization actions), social status (injury, fatalities, safety, loss of accommodation and public awareness) and interference on the environment (affected period, daily operation & diversity). Each parameters in the vulnerability assessment is allocated with a certain index value ranges from 0 (0 % damage/victims/period), 0.25 (1-25 % damage/victims/period), 0.50 (26-50 % damage/victims/period), 0.75 (51-75 % damage/victims/period) and 1.00 (75-100 % damage/victims/period). All the data products from LHV observation were reanalysed based on standardization method to evaluate their significance in developing an acceptable and practical model for landslide risk management (LRM) that will suit best to the local conditions. The next step is to establish the index value for each ideal vulnerability parameters. Finally, the total average of index value for the three types of physical, human and environment vulnerabilities is classified into five classes of vulnerabilities, namely class 1 (< 0.20) (very low vulnerability), class 2 (0.21-0.40) (low vulnerability), class 3 ( 0.41-0.60) (medium vulnerability), class 4 (0.61-0.80) (high vulnerability) and class 5 (> 0.81) (very high vulnerability). Results from this study indicate that the index value for the vulnerability on landslide hazard in Malaysia is generally higher than those of the developed countries. This is mainly due to poor awareness, knowledge and exposure amongst the public, as well as poor building codes and lack of consideration on the hazard triggering factors (intense rainfall and earthquake). It is also noted that the index value of vulnerability cannot be simply determined quantitatively because it requires data from field observations supported by the relative secondary data.

Keywords: vulnerability, risk elements, landslide risk management, Malaysia

 https://doi.org/10.7186/bgsm58201212