PENGURUSAN PUSAT PEMINDAHAN SEMENTARA BENCANA BANJIR

PENGURUSAN PUSAT PEMINDAHAN SEMENTARA BENCANA BANJIR

1.0   PENDAHULUAN

1.1   Am

Banjir adalah satu bencana alam yang berlaku disebabkan oleh faktor klimatologi atau faktor iklim seperti keadaan suhu, taburan hujan, sejatan, pergerakan angin dan keadaan semulajadi muka bumi. Di Malaysia banjir maupun banjir kilat berlaku secara tradisi, terutama di Pantai Timur Semenanjung semasa musim tengkujuh. Perubahan cuaca yang dipengaruhi oleh Monsun Timur-Laut dan Barat-Daya menyebabkan hujan lebat dan banjir terutamanya di kawasan pantai. Purata hujan tahunan adalah sebanyak 3,000 mm tetapi adalah tidak mustahil jika keamatan hujan akibat rebut boleh melebihi 100mm per jam dan 60 mm dalam masa 24 jam. Kira-kira 29,720 km² atau 9% daripada keluasan Malaysia cenderung untuk dilanda banjir dan ianya mempunyai 4.9 juta atau 21% daripada populasi penduduk Malaysia.

Peningkatan kekerapan berlakunya banjir dalam negara  berlaku secara sama ada semulajadi akibat perubahan monsun ataupun akibat peningkatan kawasan setinggan dalam bandar. Banjir biasanya disebabkan sama ada oleh hujan yang berterusan menyebabkan kuantiti yang lebih besar daripada biasa atau air sungai yang melimpah ke tebing sungai ataupun daripada kedua-duanya sekali. Dasar sungai yang semakin cetek di kawasan hilir akibat daripada banjir yang berulangan berlaku. Keadaan kawasan perbandaran yang didasari oleh tanah liat yang bersifat tidak telap air, cepat tepu dan kurang menyerap air, jika berlaku hujan lebat akan menyebabkan air sungai cepat melimpah ke tebing. Hakisan tebing yang memberikan kesan terhadap ketebalan sedimen dalam sungai juga menyumbang kepada kejadian banjir. Muhd. Barzani Gasim et al. (2007) mengenal pasti banjir yang berlaku di Dungun, Terengganu adalah disebabkan oleh empat faktor: (i) curahan hujan yang tinggi; (ii) aliran sungai yang perlahan; (iii) luruan laut ke arah darat; dan (iv)halaju dan hala tiupan angin ke daratan. Fenomena di atas adalah kesan daripada beza pasang surut yang agak besar di kawasn pantai timur.

1.2   Faktor Penyebab Banjir

Beberapa faktor penyebab yang menyumbang kepada kejadian bencana banjir, antaranya adalah seperti berikut:

(a)                Hujan Berpanjangan / Tanpa Henti

Hujan berterusan dan berpanjangan tanpa henti boleh menyebabkan banjir. Kawasan tadahan hujan terpaksa menerima lebihan kuantiti air yang banyak hasil dari hujan berpanjangan dan akan mengakibatkan banjir berlaku di kawasan sekitarnya.

(b)               Pembangunan Permodenan

Kebelakangan ini, banyak projek pembangunan dijalankan atas dasar pemodenan dan kemajuan sesuatu kawasan. Ekoran itu, ekosistem sesuatu kawasan telah terganggu akibat kerja-kerja pembangunan ini yang melibatkan tarahan bukit, sungai sekitar kawasan pembangunan menjadi sempit dengan mendakan lumpur pembinaan, penebangan pokok-pokok yang menjadi kawasan tadahan hujan. Apabila berlakunya hujan lebat, maka sungai yang sempit tadi tidak dapat menampung kuantiti air yang banyak hasil dari hujan yang turun, dan sekaligus menyumbang kepada berlakunya banjir.

(c)                Hakisan Sungai

Terdapatnya dua (2) faktor utama yang melibatkan hakisan sungai; iaitu (i) hakisan sungai secara semulajadi; dan (ii) hakisan akibat buatan manusia seperti pembungan sampah yang tidak teratur ke dalam sungai. Hakisan pada tebing sungai berlaku perlahan-lahan secara semulajadi akibat hujan lebat ataupun arus yang kuat, dan ia menyebabkan sungai menjadi semakin cetek, dan memungkinkan banjir berlaku.

(d)               Pemusnahan Hutan Simpan

Hutan simpan semulajadi menyumbang kepada penstabilan ekosistem serta penetapan suhu bumi. Melalui hutan, ia membantu dalam menyerap air antara 2% hingga 20% daripada air hujan. Apabila berlakunya pemusnahan hutan yang tidak terancang, ia akan menyebabkan ekosistem hutan tersebut menjadi tidak konsisten. Ini boleh menyebabkan banjir berlaku di kawasan hutan akibat lebihan air yang tidak dapat diserap oleh akar-akar pokok seperti kebiasaanya.

(e)               Kegagalan Perancangan Sistem Perparitan

Perancangan teliti harus dijalankan pada sistem perparitan. Kegagalan merancang boleh mengakibatkan berlakunya banjir samada banjir besar mahupun banjir kilat. Kapasiti aliran air di setiap sistem perparitan haruslah berkadaran terus dengan pembangunan setempat yang dijalankan.

1.3   Kesan Akibat Banjir

Beberapa kesan akibat banjir dapat dilihat yang melibatkan kemusnahan harta benda, kecelaruan sosial, kematian hidupan serta banyak lagi. Antara kesan negatif banjir adalah seperti berikut:

(a)                Kemusnahan Tanaman Pertanian

Tanaman pertanian musnah akibat banjir yang melanda di kawasan pertanian. Ia mengakibatkan kerugian besar kepada petani serta kesan terus kepada pengguna akibat kekurangan bekalan makanan.

(b)               Wabak Penyakit

Ekoran banjir yang melanda, kesan paling ditakuti adalah wabak penyakit yang mungkin disebabkan oleh banjir seperti penyakit taun, malaria serta penyakit berjangkit lain.

(c)                Kemusnahan Harta Benda

Sudah pastinya kemusnahan harta benda akibat banjir yang melanda boleh mengakibatkan tekanan hidup kepada mangsa apabila kehilangan harta benda seperti rumah, pakaian, kenderaan, aset dan banyak lagi.

(d)               Kematian

Kesan yang paling menyayat hati apabila adanya berlaku kehilangan nyawa akibat banjir. Kebiasaanya ianya boleh berlaku jika ciri-ciri keselamatan semasa banjir tidak diendahkan seperti bermain di kawasan banjir yang mungkin kawasan tersebut ditutupi air yang dalam atau akibat benda sekeliling yang boleh mendatangkan kecederaan dan sekaligus menyebabkan kematian.

  

(e)               Kerugian kepada Kerajaan dan Orang Awam

Banjir menyebabkan kerosakan harta awam seperti jalan raya, jambatan, bangunan kerajaan, sistem telekomunikasi dan sebagainya. Kemusnahan ini mengakibatkan kerajaan terpaksa menanggung kos baik pulih aset mahupun peralatan yang rosak.

1.4   Persediaan Awal Sebelum Bencana

Melalui kajian yang dibuat mahupun sejarah lampau sesuatu kawasan berisiko berkaitan potensi mengalami banjir, pemantauan dan pendokumentasian dibuat berdasarkan jenis bencana dan bersedia membangunkan infrastruktur Sistem Amaran Awal Bencana di tempat tersebut. Melalui maklumat tersebut, perancangan pemantapan keupayaan dari segi sumber tenaga dan peralatan dibangunkan dengan lebih sistematik. Pendedahan Sistem Amaran Awal Bencana kepada penduduk sekitar perlu dijalankan dengan kekerapan yang tinggi bagi meningkatkan kesedaran terhadap ancaman yang bakal dihadapi. Atas inisiatif Pegawai Pertahanan Awam Daerah (PPAD) di beberapa Daerah di Johor telah menubuhkan Skuad Pemantau JPAM bagi menilai keadaan semasa paras air dan memberi maklumat awal serta hebahan untuk evakuasi (jika perlu) kepada penduduk setempat melalui rondaan yang dibuat.

Mengenalpasti pusat-pusat pemindahan banjir dengan lebih awal lagi bagi memudahkan urusan evakuasi.  Antara lokasi strategik pemilihan pusat pemindahan banjir adalah seperti Dewan Orang Ramai, sekolah, balairaya, masjid dan lain-lain tempat yang difikirkan selamat untuk menempatkan mangsa banjir. Pemilihan lokasi pusat pemindahan ini perlulah bebas dari sebarang ancaman bencana lain dan selamat. Sekiranya bangunan-bangunan yang telah dikenalpasti itu adalah milik persendirian atau di bawah tanggungjawab agensi lain, maka kebenaran terlebih dahulu perlu diperolehi.  Di antara kriteria dan panduan bagi pemilihan pusat pemindahan adalah seperti berikut:

(a)                Bangunan mempunyai ruangan yang mencukupi dan selamat untuk digunakan;

(b)               Mempunyai kemudahan dan keperluan asas seperti  bekalan air, bekalan elektrik, tandas dan sebagainya; dan

(c)                Lokasi/kedudukannya selamat dari dilanda banjir dan tidak terputus perhubungan.

Persiapan ke arah penyediaan bantuan logistik dan kebajikan dibuat lebih awal lagi.  Bagi kawasan-kawasan yang pada bila-bila masa sering mengalami banjir kilat dan ribut, tahap persediaan sentiasa kemaskini dan dalam status siapsiaga. Bagi kawasan-kawasan yang sering dilanda banjir, kemudahan pangkalan hadapan sebagai tempat penyimpanan bekalan makanan adalah diperlukan.  Tujuannya ialah supaya bantuan makanan dapat diperolehi dengan kadar segera.  Kemudahan seperti ini juga diperlukan bagi kawasan-kawasan yang sering terputus perhubungan.  Jenis makanan asas yang sesuai ialah seperti beras, minyak, teh, kopi, garam, gula, tepung, ikan masin, susu kanak-kanak, biskut, sardin dan lain-lain makanan kering. Perancangan dan mengenalpasti lebih awal  sumber-sumber bekalan makanan  untuk pusat pemindahan, seperti menentukan jenis-jenis bekalan dan pusat bekalan seperti kedai-kedai, pemborong atau lain-lain sumber, dan juga menentukan tempoh sah kegunaan sesuatu bekalan makanan yang mudah rosak dan sebagainya. Jumlah makanan yang disediakan bergantung kepada jumlah   penduduk.    Walau   bagaimanapun, makanan yang disediakan hendaklah boleh menampung keperluan sekurang-kurangnya untuk 7 hari.  Dalam pada itu, tempoh input kegunaan barang-barang ini hendaklah sentiasa diawasi supaya tidak melebihi  tarikh yang ditetapkan.

Kenderaan dan bot-bot penyelamat hendaklah ditempatkan lebih awal di kawasan yang mudah dilanda banjir bagi mengelakkan sebarang masalah sekiranya jalan raya ditenggelami air dan tidak boleh dilalui.  JPAM bersama agensi-agensi penyelamat lain diletakkan dalam keadaan bersiapsiaga menghadapi sebarang kemungkinan bencana banjir. JPAM sentiasa memastikan semua peralatan menyelamat dan kenderaan berada dalam kondisi terbaik dan boleh digunakan bila-bila masa diperlukan. Kelengkapan menyelelamat ini perlulah dilengkapi dengan lain-lain peralatan seperti jaket keselamatan, pendayung, lampu suluh, lampu limpah, tali, pelampung, khemah, generator dan lain-lain peralatan yang difikirkan perlu dalam operasi menyelamat.

Perancangan awal bagi gerak kerja pegawai dan anggota JPAM dilakukan lebih awal dengan susun atur penugasan mengikut keutamaan. Memastikan senarai nama pegawai dan anggota berserta alamat dan nombor telefon sentiasa dikemaskini bagi membolehkan panggilan bertugas dan kerahan tenaga dapat dilakukan bila diperlukan. Semua ini menjadi tanggungjawab PPAD bagi setiap Daerah.

Sebagai langkah pencegahan, beberapa agensi kerajaan yang bertanggungjawab terhadap sistem perparitan dan saliran, perlu mempastikan semua sistem saliran air dibersihkan daripada sampah sarap  terutamanya  sistem saliran di bandar-bandar.  Pengaliran air yang sempurna dapat mengurangkan potensi berlakunya banjir. Papan tanda amaran banjir juga perlu diletakkan di kawasan dan jalan-jalan yang sering dilanda banjir untuk panduan orang ramai.

Program kesedaran dan kependidikan awam hendaklah dilaksanakan secara berterusan dan holistic bagi meningkatkan tahap kesiapsiagaan masyarakat mengahadapi bencana banjir. Latih amal pengurusan dan pengendalian bencana yang melibatkan semua agensi terlibat hendaklah diadakan secara berterusan bagi meningkatkan kompetensi setiap anggota agensi melalui pelarasan yang dibuat oleh pihak Majlis Keselamatan Negara (MKN).

Landslide: Man-Made Failure Due To Emphasis On Development Projects

Man-Made Failure Due To Emphasis On Development Projects

Landslides have posed serious threats to settlement and structures that support transportation, natural resource management and tourism. More than 100 hillslopes had been identified by Malaysian Public Works Department (PWD) as risky for possible landslides (Mukhlisin et al., 2010). Gue and Tan (2006) in the study of causes of slope failure found that eighty-eight percent of the 49 cases of slope failure in Malaysia are man-made slope failures. The failures are mainly due to the either design errors or construction errors. The finding was supported by Jamaluddin (2006) who studies on many cases of slope failures in Malaysia indicated that the slope failures are mostly attributed to human factors such as negligence, incompetence, lack or poor maintenance system, ignorance of geological inputs, unethical practice and various negative human attitudes.

According to the National Slope Master Plan (2009), the main contributing factors to trigger the landslides are found to be geological causes or ground conditions, hydrological causes, morphological causes, physical causes and human causes. These main contributing factors are based on the review of selected worldwide literatures. A total of 30 case studies excluding Malaysia case studies were carried out with reference from countries such as China, Italy, Thailand, Russia, Taiwan, Germany, Korea, Japan, and Australia. The statistics indicate that ground conditions and human causes are the major contributing factors of landslide failures on a worldwide basis. In addition, the occurrence of landslides also due to mismanagement of land use due to the increasing number of population and the needs of land for producing agricultural products that, that force people to stay in landslide hazard areas (Soralump, 2010).

Gue and Tan (2006) found that most of the slope failures in Malaysia are due to design errors, construction errors, design and construction errors, geological features and maintenance. The study is based on 49 investigation cases of primarily large landslides on residual soils.

Causes of Landslides	Numbers of Cases	Percentage (%)
Design Errors	29	60
Construction Errors	4	8
Design & Construction Errors	10	20
Geological Features	3	6
Maintainance	3	6
Total	49	100

Table 1 Causes of Landslides (After Gue & Tan, 2006)

The results of the study indicate that 60% of the failures are due to inadequacy in design alone. The inadequacy in design is generally the result of a lack of understanding appreciation of the subsoil conditions and geotechnical issues. Failures due to construction errors alone either of workmanship, materials and/or lack of supervision contributed to 8% of the total cases of landslides. About 20% of the landslides investigated are caused by a combination of design and construction errors. For landslides in residual soil slopes, the landslides caused by geological features only account for 6% which is same as the percentage contributed by a lack of maintenance (Gue and Cheah, 2008).

National Slope Master Plan (2009) also has similar study after Gue and Cheah (2008). The causes of landslides can be due to the abuse prescriptive methods, inadequate study of past failures, design errors including insufficient site specific ground investigation. However, lack of appreciation of water such as underestimating existing groundwater table and inadequate capacity of surface drainage is also one of the factors causing the landslides. A guideline from government agencies like Minerals and Geosciences Department and Department of Town and Regional Planning stated that the degree of risky hilly area starts at 25 degree. Besides, the hilly area with intrusive acid rock gives higher probability to cause a slope failure (Mukhlisin et al., 2010).

Farisham (2007) has carried out the study on rapid landslide occurrence at the hillside development areas, in the Klang Valley. The study was focused on the architectural approach, the theory and the practice in the hillside development, aspects to be considered by the architect, in proposing the site layout. The study found that the occurrences of landslides in Klang Valley are due to the design and construction failure of the retaining wall, lack of maintenance and triggering by rainfall. In addition, Farisham (2007) concluded that understanding on original terrain is very important; site layout proposal must be done through detail site investigations. The selected design approaches and method of construction for hillside development have given major impact on the safety of the development. Therefore, the hillside area must be designed and constructed, with proper understanding and should be responsive to the natural terrain, in order to protect the stability of the land due to the fact that when the land stability is low or bad the chances of landslide occurrence is very high.

My Overview on Landslide in Malaysia

Landslide History in Malaysia

The record of landslides in Malaysia was compiled by Abd Rasid (2006) as shown on Appendix. He reviewed some of the landslides occurred in Malaysia from 1990 to 2004. The earliest written record of landslide in Malaysia is the rockfall that occurred on 7 December 1919 at Bukit Tunggal, Perak, which claimed 12 lives and damaged property. After the country gained independence in 1957, the first national tragedy was a landslide at Ringlet, Cameron Highlands which occurred on 11 May 1961. About 700 people and two bulldozers came to assist and approximately 30 people were rescued. This tragedy, however, claimed 16 lives.

From 1973 onwards, a considerable number of landslides were reported in the local newspapers. From 1973 to 2007, indicates an increase in the number of fatalities with an increase in the number of landslides (PWD on National Slope Master Plan (NSMP), 2009-2023).

The Highland Towers tragedy on 11 December 1993 that claimed 48 lives had a major impact on national policy. Lack of storm water planning and design is the main reason that the cause of landslide. It was due to this landslide that on 18 May 1994 the Cabinet Meeting made a decision to; (a) form the Special Malaysia Disaster Assistance and Rescue Team (SMART); (b) form a mechanism under the National Security Council (MKN) in the Prime Minister’s Department for the management of disasters on land. These two major decisions by the Government were later implemented by the issuance of National Security Council Directives No. 19 (MKN Arahan 19) and No. 20 (MKN Arahan 20). It was also around this time that the public began to become aware of landslide hazards. The highest fatality recorded for a single landslide event, was on 26 December 1996 where a debris flow caused by Tropical Storm Gregg wiped out a few villages in Keningau, Sabah and claimed 302 lives.

Most major landslides resulted in fatalities and injuries. However, some major landslides along highways, although without fatalities, resulted in serious disruptions to the transportation network and adversely affected the public. For example, the rockslide at Km 21.8 of the New Klang Valley Expressway (NKVE) in 2003 claimed no fatalities, but it is the landslide with the highest economic costs to date because of the high direct and indirect cost associated with the half-year massive traffic congestion, road closures and diversions in the Klang Valley.

My Overview on Slope Stability

Slope Stability

Evaluating the stability of slopes in soil is an important, interesting, and challenging aspect of civil engineering. Concerns with slope stability have driven some of most important advances in our understanding of the complex behavior of soils. Extensive engineering and research studies performed over the past 70 years provide a sound set of soil mechanics principles with which to attack practical problems of slope stability (Duncan & Wright, 2005).

Slope stability addresses the tendency of soil masses to attain an equilibrium state between the strength of the soil and the force of gravity.  Department of Irrigation and Drainage Malaysia (DID) mention that their facing of slope stability problems which often occur in the construction of embankment over soft soils, and the instability of waterway slope (e.g. river and pond) due to seepage, drawdown, or erosion by flowing water. Placement of stockpiles, heavy equipment, or other surcharges may also cause instabilities of the slope, particularly during construction stage. In general, altered slope, whether man-made or natural need to be analyzed and checked to ensure that it has adequate factor of safety against slope failure.

Guidelines from Department of Agriculture (DOA) and Malaysia Agricultural Research and Development Institute (MARDI) (1993), and DOA (2000) gives a definition which any area on 300m above sea level, its can consider as ‘highland’, where there have a change in temperature, topography and forest type. Meanwhile, slope more than 25^o where consider as a ‘steepland’.

 Slope Classification

Class	Topography	Degree of Steepness
C1	Flat	0o – 2o
C2	Undulating	2o – 6o
C3	Wavy	6o – 12o
C4	Hilly	12o – 20o
C5	Very Hilly	20o – 25o
C6	Steep	25o – 30o
C7	Very Steep	>30o

Table 1 Slope Classifications

Type of Slope Instabilities

In general, slope stability problems commonly encountered by DID can be categories into three (3) types (DID Manual, 2009), namely:

(a)    Infinite Slope Failure – A slope that extends for a relatively long distance and has a consistent subsurface profile may be analyzed as an infinite slope, the failure plane for this case is parallel to the surface of the slope and the limit equilibrium method can be applied readily;

(b)   Sliding Block Failure – Occurs when the wedge type of sliding mass that cut through the fill and a thin layer of weak soil essentially moves as a block; and

(c)    Circular Arc Failure – occurs when the ground sinks down and adjacent ground rises and the failure surface follows a circular arc.

Slope Stabilization Methods

Slope stabilization methods generally aim to reduce driving forces, increase resisting forces, or both. Driving forces can be reduced by excavation of materials from appropriate part of the unsuitable ground and drainage of water to reduce the hydrostatic pressures acting on the unstable zone. Resisting forces can be increased by introducing soil reinforcements, such as soil nails and geo-synthetic materials, and retaining structures or other supports.

My Overview of Landslides: Literature Review

 Landslides

Natural hazards like landslides, avalanches, floods and debris flows can result in a lot of property damage and human losses in mountainous regions. Landslides are among the most hazardous natural disasters and during the years, landslide hazard and risk have been attempted to be assessed and its spatial distribution to be portrayed (Metternicht et al., 2005). This geological phenomenon includes a wide range of ground movement and generally defined as a down slope movement of a mass of soil and rock material (Cruden, 1991).

Landslides are very common geological slope failure phenomenon in some countries like Brazil, Peru, Iran and Malaysia. Generally, lots of their areas have been subjected to slope failure under the effect of numerous factors, and triggered by events such as extreme rainfall or earthquake or both.

Landslides Descriptions

There are a number of definitions of landslide, range from geomorphic features and processes it encompasses. Derek H.C. (2005) wrote that the term landslide is sometimes felt to be inadequate because many types of slope movement do not involve sliding. The geomorphologist term mass wasting is little improvement. Cruden (1991) has suggested a simple definition of landslide ‘the movement of mass of rock, debris, or earth down a slope’. Sharpe (1938) begins to define landslide as ‘the perceptible downward sliding or falling of a relatively dry mass of earth, rock or mixture of two’. J. Suhaimi (2006): Sharpe (1938) it was explained further by Terzaghi (1943) ‘landslide is rapid displacement of rock, residual soil or sediments adjoining a slope and center of gravity of moving the mass advances in a downward and outward direction’. While Varnes (1978) defines landslides as ‘downward and outward movement of slope forming materials composed of natural rock, soils, artificial fills or combinations of these materials’. Hutchinson (1978) explain landslide as ‘relatives rapid down slopes movement of soils and rock, which take place characteristically on or more, discrete bounding slip surfaces which define the moving mass’. However ‘the movement of rocks, debris or earth flowing down a slope’ by Cruden (1991) is the most widely used (J. Suhaimi, 2006; Fell, 2000).

 Landslides Classification

The commonly used type of landslides was proposed by Varnes (1978), that category the landslide into five (5): falls, topples, slides, lateral spread and flows. Then has been updated and partly revised by Cruden & Varnes (1996) with another category, which are composites (combination of types).

Type of Movement		Type of Material
		Bedrock	Engineering Soil
			Predominantly coarse	Predominantly fine
Falls		Rock fall	Debris fall	Earth fall
Topples		Rock Topple	Debris Topple	Earth Topple
Slide	Rotational	Rock Slide	Debris Slide	Earth Slide
	Translational
Lateral Spreads		Rock Spread	Debris Spread
Flows		Rock Flow (deep Creep)	Debris Flow (Soil Creep)	Earth Flow (Soil Creep)
Composites (combination of two or more principle type of movement)

Table 1 Category of Landslide

The cause of landslide as listed below (H.R. Thomas, 2002):

a)      Overloading slope;

b)      Increase fill on slope without adequate drainage;

c)      Remove vegetation;

d)     Increase the slope rate;

e)      Increase the slope length by cutting at the bottom of slopes;

f)       Changing surface drainage route; and

g)      Changing in subsurface drainage route.

No.	The Causes
1	Overloading slope (weight of building or road)
2	Increase fill on slope without adequate drainage
3	Remove vegetation
4	Increase the slope rate
5	Increase the slope length by cutting at the bottom of slope
6	Changing surface drainage route
7	Changing in subsurface drainage route

Table 2 The Causes of Landslide

Landslide did not occur due to a single factor, Cruden & Varnes (1996) explains, landslide can triggered by rainfall, earthquakes, volcanic activities, changes in groundwater, disturbances and change of slope profile by construction activities or combination of these factors. This explanation is supported by N.W. Chan (1997, 1998, 1999), Main Rindam (1996) and Crozier (1986), landslide did not a happened naturally but it was a result of human actions. W. Mokhtar (2006) stressed that, main factor that caused slope failure or landslides at numbers site in hillside development in Malaysia are rainfall and storm water activities. 

Prevention of Landslide

Prevention rather than remediation is desirable where slope failure is likely to be rapid and there is a high risk of damage and injuries. These failures flow slides, earthquake-induced slides, and rock slides. Potential landslides due to these causes can be reduced in a cost-effective way by taking several actions:

a)      Identifying landslide risk through hazard mapping and past experience, then implement a plan of hazard reduction on a prioritized basis.

b)      Periodic inspections of facilities that are vulnerable to landslides to observer any early signs of distress and, if appropriates, take preventive action to avert a landslide.

c)      Maintaining and improving drainage measures in area vulnerable to landslide.

d)     Protecting lifeline facilities, buildings and other place of public access from earthquake-induced landslides.