When China observed a day of mourning on 15th August 2010 for the victims of the previous week’s deadliest mudslide in Zhouqu, Gansu province, similar calamities of varying scale occurred elsewhere in various parts of Asia -Pacific region. Landslides are common occurrences closely connected with major natural disasters such as earthquakes, volcanoes, wildfires, and floods, and they constitute major hazards if they are widespread. Flood warnings go hand-in-hand with alarms over potential landslides – rain-triggered disasters. With unprecedented frequency of extreme weather calamities heightening, landslides – mudslides are expected to feature increasingly in our disaster management nightmares.
Mid-year 2010 saw countries in the southern sub-continent i.e. India, Pakistan, and Bangladesh battered by torrential rains. In Bangladesh, heavy rains in mid-June 2010 triggered landslides in Cox’s Bazaar and Bandarban districts. In Cox’s bazaar, 45 bodies were recovered from the Ukhia and Teknaf landslides. The disaster did not spare those in the security services either. In Himchharhi, eight members of the army’s Engineering Construction Battalion were killed when landslides (a big chunk of a hill) hit them. Twenty army vehicles were also buried in the mud. Thousands of houses collapsed due to the mudslides. In India-controlled Kashmir, flash floods sent massive mudslides down remote desert mountain sides crushing homes. At least 132 people were killed and 500 others missing.
In Pakistan, landslides triggered by the worst floods in 80 years obstructed access into areas already isolated by the massive disaster, thus hampering relief efforts. Aid workers had to use mules or travelled on foot to reach people in dire need of assistance. With numerous roads destroyed by the floods and blockages by landslides some of the affected areas were completely marooned. (i)
In Malaysia, although only a minor landslide incident took place on 10th August 2010, questions about mitigating measures were immediately raised. In the disaster which struck Duyong in Malacca state, more than 1,000 homes were hit by flash floods and a landslide. The landslide missed several shop lots. Four days later heavy rains in Penang caused a hillslope retaining wall to collapse, sending a torrent of muddy water into low-costs flats nearby.
Like its other ASEAN neighbours, Malaysia too has its share of landslides, occurrences of which are common in hilly terrains. With the country moving rapidly towards urbanization, some landslide occurrences proved to be serious hazards involving fatalities and losses, with severe damages to the infrastructure. Since the eighties, especially beginning with the construction of the North-South Expressway, landslides had been closely monitored by the authorities. Increasing urban land use had seen occupation of more hilly lands and consequent to a number of landslides involving affluent suburban areas in the capital over the past few years led the Malaysian government to ban hillside development in 2008.
Malaysia, with its experience of seasonal monsoon and share of extreme weather triggered disasters, has undertaken mitigation measures to reduce the risks of landslides. Maintenance of the hilly slopes along the North-South Expressway (NSE) a major highway in the country, involved installations of high-tech devices to detect impending landslides and reduce rock falls. The detectors gauge rain on priority slopes and collects data instrumental for determining maintenance requirements on the slope concerned. A total of 70 locations along the expressway have been equipped with the Real Time Monitoring System (RTMS), the first in South-East Asia. The last major landslide along the NSE was in 2004. (ii)
As for Indonesia, a vast tropical archipelago spanning more than 17,000 islands, landslides kill dozens of people every year. With the exceptions of major incidents of magnitude, most of the landslides only made local news. Heavy rains nonetheless triggered landslides on Flores Island in February 2010 and Buru Island, eastern Maluku province end of July 2010. In the former incident, five villages were marooned following landslides which cut off access and blocked network of roads in the affected area.
In Indonesia, the state railway company (PTKA) usually increase patrols of its lines during the rainy season since some spots are highly prone to landslides. In late April 2010, train traffic between a number of stations (Labakjero, Leles, Banjar, and Wangon) was disrupted for several hours due to landslides. (n)
Just a month earlier, the inter-monsoonal rains caused landslides in Central Bengkulu and Kepahiang districts, both of which are particularly vulnerable to landslides during the rainy season. Several landslides occurred in these areas during late March 2010 blocking major road connections. On March 11, a landslide hit Ciawitali hamlet in Cianjur, West java, destroying five houses and killing 10 people.
In mid-march 2010, a massive mudslide of volcanic material from Mount Talang, hit Sungai Janiah village in Solok regency, leaving 1,500 residents isolated. In its advance, the mudslide (locally known as galado) damaged bridges, and swept away eight houses along a river. Huge amounts volacanic material, (tens of thousands of cubic metres) from Mount Talang’s eruption in 2005 had accumulated at the upstream areas of four rivers posing threats to the population below. There still remain large volumes of volcanic materials and boulders at the upstream areas which could be carried by the rivers consequent to continuous heavy downpours. (iii)
Over in the Philippines (mid-July 2010) when Typhoon Baysang exited after ravaging the northern part of the country, it was not the end of the story. Heavy rains in the Surrallah town, South Cotabato province, triggered landslides which buried several homes in a village. Even moderate rains following the aftermath of a typhoon could still trigger floods and landslides in low-lying and hilly areas which have been already drenched to hilt. (iv)
Two months earlier, in May 2010, mudslides buried dozens of shanties in Nanapan, a remote gold mining village in southern Philippines, killing at least 26 people. One mudslide slammed into about 30 shanties. The area, already known to be mudslide prone was saturated consequent to days of rain. Residents in the affected area had ignored warnings to evacuate. The gold mining village, at Mount Diwata (580 miles south-east of Manila) has about 40,000 residents, mostly miners and their families.
Thailand too had its brush with landslides (early August 2010) in the southern province of Ranong, Thailand triggered after a nonstop overnight rain. Access to Ranong’s provincial seat was blocked by mud, rocks, and trees dragged down by the landslide. (s)
The ominous signs that extreme weather patterns will continue to be more frequent are there. The number of massive floods which happened in China and Pakistan has already triggered usage of the term “mega disasters”. As more torrential downpours loomed over the future, rain-triggered landslides/mudslides could be playing out often in our disaster management nightmares.
(i)Reuters. Landslides complicate Pakistan flood relief efforts. Mon Aug 9, 2010 5:27pm IST. Junaid Khan(ii)The Star. Friday June 18, 2010. Devices to detect landslides along NSE.SUBANG(iii)The Jakarta Post. Mudslide isolates 1,500 residents in Solok. Syofiardi Bachyul Jb, Padang Thu, 03/18/2010 (iv)Philstar.com. Landslide, tornado hit 2 South Cotabato towns. July 15, 2010