International Journal of Engineering & Technology, 7 (4.35) (2018) 760-764 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET Research paper Flood and Flash Flood Geo-Hazards in Malaysia F. S. Buslima1*, R. C. Omar1, Tajul Anuar Jamaluddin2, Hairin Taha1 1Forensic Engineering Group, Institute of Energy Infrastructure, Universiti Tenaga Nasional 2Geology Programme, Faculty of Science & Technology, National University of Malaysia *Corresponding author E-mail: [email protected] Abstract Floods are natural phenomena of geo-hazards that usually happened when experiencing prolonged heavy rainfalls. Floods in Malaysia can be categorized into monsoon floods and flash floods. Monsoon floods is caused of Northeast Monsoon season commences in early November and ends in March that brings heavy rainfall, particularly to the east coast states of Peninsular Malaysia and western Sarawak. Flash floods usually occur in areas with rapid development by a rapid rise in water level, high velocity, and large amounts of debris. Flooding that occurred in December 2014 can be classified as worst floods that affected several states in Peninsular Malaysia, and the worst affected is Kelantan state. This disaster was recorded more than 200,000 people were affected with 21 people were killed and gives a massive impact on people, properties, agriculture, livestock, and infrastructure facilities. Following the worst floods that hit Malaysia in 2014, the opinions and views from various parties such as subject matter experts was needed to produce mitigations and prevents of the flood disaster at once to minimize vulnerability to hazard. Keywords: Flood; Flash Flood; Flood Implication; Kelantan; Mitigation Plan 1. Introduction 2. Flood and Flash Flood Geo-hazards are natural phenomena that typically triggering the natural disasters cause fatalities, damages, and severe impacts to Flooding is defined as the accumulation of water within a water social and economic. Hazard is an event or physical condition that body and the overflow of excess water onto adjacent floodplain has the potential to cause fatalities, injuries, property damage, land. The floodplain is the land adjoining the channel of a river, agricultural loss, damage to environment, interruption of business, stream, ocean, lake or other watercourse or water body that is or other types of harm or loss [1]. These natural disasters consist susceptible to flooding [1]. Floods in Malaysia can be categorized of landslide, earthquake, tsunami, flood and others. Flooding is into monsoon floods and flash floods. Rainfall distribution pat- hydrologic hazards that occur naturally triggered by heavy rain- terns in Malaysia are influenced by the seasonal wind flow pat- fall. terns and the local topographic features. Malaysia experienced the Hazards associated with flooding can be divided into primary Northeast Monsoon season commences in early November and hazards, secondary hazards and tertiary hazards or long term haz- ends in March. Figure 1 shows the rainfall patterns that influenced ards [2]. The primary hazards are effects of floods due to direct by the Northeast Monsoon brings heavy rainfall and causes floods, contact with the flood waters. With high velocities, streams are particularly to the east coast states of Peninsular Malaysia and able to transport larger particles as suspended load. These large western Sarawak. particles can include not only rocks and sediment, but during the Flash floods usually occur in areas with rapid development. Flash flood, could include such large objects as automobiles, houses and floods are characterized by a rapid rise in water level, high veloc- bridges. The secondary hazards are that occur because of the pri- ity, and large amounts of debris. Flash floods are cause by factors mary hazards (flooding), such as disruption of services and health the intensity and duration of rainfall as well as the steepness of impacts (famine and disease).The tertiary hazards are long term watershed and stream gradients. Flash flooding in urban areas is changes such as changes in the position of river channels. an increasingly serious problem due to removal of vegetation, The purpose of this paper is to briefly outline the flood scenario in paving and replacement of ground cover by impermeable surfaces Malaysia especially the flood disaster in 2014 is said to be the that increase runoff, and construction of drainage systems that worst event ever experienced in Kelantan and Terengganu as well increase the speed of runoff [1]. as its implications of the floods in aspect of social, economic and Based on the hydrological perspectives, a difference between infrastructure. These issues followed by flood disaster manage- flood and flash flood is the period taken by river flow to recede ments to overcome the impacts of flooding with five activity areas, back to the normal level [4]. Flood (or monsoon floods) takes a namely prevention, preparedness, response, recovery and govern- long term and may last a week or more to return to the normal ance. water flow level, whereas, flash flood takes only few hours. Na- tional Oceanic and Atmospheric Administration, NOAA stated that flash floods occur within a few minutes or hours of excessive rainfall and most of events followed by slow-moving thunder- storms, thunderstorms repeatedly moving over the same area, or Copyright © 2018 Authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Engineering & Technology 761 heavy rains from hurricanes and tropical storms [5]. Flash floods 18 people were killed Dec 2006 are events of short duration with a relatively high peak discharge 6 & Jan Flood in Johor and tend to occur frequently but at a very small scale [6]. 2007 [8] Estimated USD 489 mil- lion in damage 28 people were killed 2008 7 Flood in Johor Estimated USD 21.19 [8] million damage four people were killed Estimated 45,000 hectares Flood in Kedah and of paddy fields were de- 8 2010 [8] Perlis stroyed More than 50,000 evacu- ees affected in Kedah Flash flood caused by the water released from Sul- 2013 Flash Flood in Cam- tan Abu Bakar dam 9 [11] eron Highlands Three people were killed 80 houses affected and 100 vehicles damaged Several states in Peninsu- lar Malaysia were af- fected; Kelantan, Tereng- Fig. 1: Rainfall patterns that influenced by the Northeast Monsoon [3] ganu, Pahang, Perak, Sa- Dec 2014 bah, Negeri Sembilan, & Jan Flood in Peninsular Johor, Perlis, Kedah and 3. History of Flood in Malaysia 10 2015 Malaysia Sarawak [12] More than 200,000 peo- Floods and flash floods in Malaysia often happen when experienc- ple were affected with 21 ing prolonged heavy rainfalls. Flooding during the monsoon sea- people were killed son often experienced in the east coast states of Peninsular Malay- Estimated more than RM sia such as Kelantan, Terengganu and Pahang and Western Sara- 1 Billion damage wak. According to Malaysian Medical Relief Society, MERCY, Flash flood that affected rapid urbanization of floodplains such as those in Kuala Lumpur, four main roads in Kuala Penang and Sarawak, and upstream development of hill land have Lumpur May 15 cars were submerged rendered many areas vulnerable to hazardous flash floods [7]. Flash Flood in Kuala 11 2016 and hundreds more were Historically, there have been big flood events in 1886, 1926, 1931, Lumpur and Selangor [13][14] trapped in Kuala Lumpur 1947, 1954, 1957, 1965, 1967, 1970/1971, 1988, 1993, 1996, More than 300 evacuees 2000, 2006/2007, 2008, 2009, and 2010 [8]. Kuala Lumpur was affected at Dengkil, Se- hit by major flash floods in 1971 as several riverbanks broke due langor to heavy monsoon rains. This event affected more than 180,000 evacuees with 32 fatalities [7]. The latest of worst flood in Malay- 3.1. Review of 2014 Malaysia Flood sia is happened on December 2014 has been the worst floods in decades. Table 1 shows a summary of the history of floods and The history of worst flooding were recorded in 1967, where heavy flash floods that occurred in Malaysia form 1996 until 2016. monsoon rains that have hit the state in east coast of Peninsular Malaysia especially Kelantan and Terengganu as well as some Table 1: Flooding History in Malaysia states in West Malaysia such as Perak, Pahang, Kedah, Perlis, No. Year Floods Incidence The effects of disasters Johor and some places in Penang. This event led to more than 241 people were killed 250,000 people in urban and rural areas have been affected by Estimated more than USD Floods brought by 97.8 million damage to floods recorded as the biggest flood to destroy the West Malaysia 1 1996 [8] Tropical Strorm Greg infrastructure and prop- [15]. Flooding that occurred in December 2014 can also be classi- in Keningau, Sabah erty fied as worst same as the floods in 1967. Several states were af- Destroyed thousands of fected namely Kelantan, Terengganu, Pahang, Perak, Negeri Sem- houses bilan, Johor, Perlis and Kedah as well as Sabah and Sarawak. Floods caused by 15 people were killed in The flood disaster in 2014 is said to be the biggest event ever ex- heavy rainfall in Kelantan and Terengganu perienced. Especially in Kelantan, the flood area affected includes 2 2000 [8] Kelantan, Terengganu More than 10,000 evacu- the districts of Kota Bharu, Machang, Pasir Mas, Pasir Puteh, and northern Peninsu- ees affected in northern Tanah Merah, Gua Musang and Tumpat. District of Kuala Krai is lar Malaysia Peninsular Malaysia areas badly hit by the floods especially Manik Urai and Dabong. Storm causes flooding This state suffers from two phase of flood. The first phase began Floods brought by and landslide in eastern Tropical Storm Malaysia on December 14 – 17, 2014, and the second phase occurred on 3 2001 [9] Vamei in eastern Five people were killed December 20 – 24, 2014.