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December 2021 Vol 2 N0 6

Your Editor, Jamari Mohtar, is leading an internal online discussion with his team on the recent worst flood in Selangor, as Let’s Talk! transits from a fortnightly to a weekly newsletter … 

  • The main reason why flood occurs is simply the result of continuous heavy rain for hours or days, with the lyrics of a song describing it as … it pours, man, it pours …
  • In fact, the US weather service defines flash flood as flooding that begins within 6 hours, and often within 3 hours, of the heavy rainfall.
  • Thus, flash floods are distinguished from regular floods by having a timescale of fewer than six hours between rainfall and the onset of flooding.
  • Whatever types of flood, all other reasons for its occurrence such as overflowed rivers, clogged drainage, less forests and trees, etc., are supplementary to this main reason of a continuous downpour.
  • The only difference climate change adds to the flood equation is the increasing frequency of rainfall and its unpredictability that have been occurring for the past few decades.
  • Water (rain) is not our enemy; it is our friend sent by Allah (or Mother Nature for those who don’t believe in the existence of God) as a blessing for the survival of the human species.
  • And climate change that has been the talk of the world (not just the talk of the week in Let’s Talk!) for decades is itself not the result of the destructive work of water, but that of humankind which is inflicted on Nature via relentless logging and burning of fossil fuel, among others, all in the name of progress and development for humankind.
  • Of course we need progress and development that distinguish us from the animal species but that doesn’t mean we need to attain them at the expense of the very abode we live in.
  • Thus, it is very apt when the Quran says: “Calamities (mischief, corruption) have appeared on land and sea because of what the hands of the people have earned, so that He (Allah) makes them taste some of what they did, in order that they may return (to the right way).” Ar-Rum (30): 41.
  • And the right way alluded to in the Quran is sustainable development, the very progress that is in tune with not only our material well being but also a holistic one which takes into account the non material aspects of development such as a flourishing flora and fauna, emotional well being in having a good physical and mental health, spiritual well being, etc.
  • Coming back to the issue of climate change, most people are still perplexed why climate change is the cause of frequent and unpredictable rain, with some experts in a denial mode.
  • Climate change is not really a rocket science and is very easy to grasp. The act of destruction in the form of relentless logging, massive deforestation and the burning of fossil fuels has resulted in an excessive increase in the emission of greenhouse gases, which in turn causes global warming.
  • When temperature increases, the air has more ability to hold more moisture. This moisture will then come down as rainfall.
  • When the atmosphere is sucking up more water (around 7% more water for every 1° Celsius rise in temperature), heavy rainfall are more likely to happen in the coastal regions, and severe droughts are more likely to occur in the middle of continents.
  • This is the reason why in one country, there could be flood in one region and raging forest fires in another, both occurring at the same time.
  • The recent worst flood in Selangor is quite an anomaly because the annual monsoon season of October to March with its worst flood is normally associated with the east cost states of Kelantan, Terengganu and Pahang.
  • According to Universiti Kebangsaan Malaysia climatologist Prof Dr Fredolin Tangang, the tropical depression that hovered over the Straits of Malacca was a remnant of a low-pressure atmospheric system that was first detected on Dec 15 when it appeared off Sarawak and the South China Sea, which then moved westward.
  • “I think by Dec 16 to Dec 17 the system was very close to the east coast causing moisture convergence over Terengganu, Kelantan and Pahang resulting in heavy rainfall, (and) that was why there were also floods there,” he said.
  • A tropical depression is formed by air that moves towards lower areas, rises and creates thunderstorms with strong winds. Depending on the ocean temperature, when it travels overland, it is supposed to peter out.
  • But this time around, according to Prof Fredolin, who’s also the UKM chair of the Department of Earth Sciences and Environment, it did not peter out. On the contrary the remnants of that tropical depression strengthened as it went towards the Straits of Malacca.
  • This, he said, triggered the continuous rainfall in the west coast, resulting in the worst flood in Selangor during the weekend of December 18 and 19.
  • The lesson here is that we can no longer assume the monsoon season of October to March will cause the traditional massive floods only in the east coast states, as it has been seen that it now can also happen in the west coast of Selangor, Kuala Lumpur and Negri Sembilan.
  • But it is indeed quite intriguing the moisture convergence over Terengganu, Kelantan and Pahang that caused floods there brought about by the tropical depression associated with the low-pressure system appearing off Sarawak and the South China Sea did not peter out as usual.
  • Instead, the remnant of the tropical depression continued to gain strength as it travelled inland to the west coast and hovered over the Straits of Malacca.
  • Could this be the work of climate change? The answer is not so straightforward, said Prof Fredolin, as this required further detailed study with computer simulations.
  • Despite this, he said it could still be concluded that climate change has been attributed to almost all extreme weathers in the last two to three decades.
  • Also when the remnant of that tropical depression gained strength as it travelled inland instead of petering out as usual, this gave an element of unexpectancy when the volume of rainfall in Selangor on that fateful day in 24 hours was worth the volume of rainfall in a month.
  • This implies the worst flood in Selangor is an unexpected event when despite everybody was caught with their pants down, it was then politicised by “pants-down” politicians of all hues to whack one another.
  • Tropical depression that had unexpectedly hit Selangor and caused the worst flood with tremendous damage in that state can recur again, according to Prof Fredolin.
  • This is because such a tropical depression, though occurring for the first time in Selangor, had happened in the past in states such as Sabah, Johor and Penang where it had also triggered worst floods.
  • Moreover, Malaysia is now facing the Northeast Monsoon season from October to March, bringing in more monsoon rain that originates in China and the north Pacific.
  • Until March is over, who can say that the worst is over? Although March is at the tail end of the Northeast Monsoon and thus, unlikely for the worst flood to occur in that month, again who can say the worst is over, if we factor in climate change with its frequent and unpredictable rain and flood?
  • But as in all things, a negative or positive event will have its opposite positive/negative element, if we only care to find them instead of indulging in the blame game.
  • The positive element aka blessing in disguise in this negative event of the worst flood in Selangor is the heightened sense of preparedness and awareness, forged among all parties in facing the possibility of a recurrence of the event while the Northeast Monsoon is still on until March.
  • More and more people now are aware of the need to keep themselves updated with the latest weather forecast provided by the Met Station when making plan for travel.
  • Meanwhile the National Disaster Management Agency (Nadma) in response to the Meteorological Department’s forecast of monsoon rain and low weather pressure at the South China Sea from Dec 27 until Dec 30, has instructed district officers to ensure maximum preparedness, and following it up with each state and district.
  • It is also coordinating logistical assistance, including bringing additional water pumps to areas such as Mentakab, while 22 water pumps are still being used to drain water in flooded areas in Selangor, including in Sepang and Kuala Selangor.
  • Nadma also said the Geoscience and Mineral Department of the Ministry of Energy and Natural Resources has identified 44 landslide locations in Selangor and Kuala Lumpur, including taking necessary actions with the cooperation of various agencies like the Public Works Department.
  • Also perk-up and in a state of full preparedness is the Fire and Rescue Department of the Ministry of Housing and Local Government, whose Director General, Datuk Seri Mohammad Hamdan Wahid said it is ready for the possibility of a second wave of floods.
  • The department has been monitoring potential dangerous and at-risk areas in Pahang, Sarawak and Selangor by conducting 13 monitoring operations in Pahang, 34 in Sarawak and 20 in Selangor.
  • “We learnt our lesson based on what happened in Selangor. We are ready for the possibility of a second wave that could happen within a day or two until Dec 29 according to reports by the Meteorological Department,” added Hamdan.
  • The basis for this transparency, accountability and preparedness to become the order of the day was first laid by Prime Minister Ismail Sabri Yaakob who admitted to weaknesses in the government’s response to flooding that has led to more than a dozen deaths and the displacement of over 60,000 people.
  • “I don’t deny (the weaknesses) and will improve in the future,” Ismail Sabri said on Dec 21. “The responsibility is not that of the federal government alone, but also the state governments, and the frontliners are the districts.”
  • This is actually a subtle hint at the opposition Pakatan Harapan which has been very vocal in criticising the government that it must also take equal responsibility for the worst flood in Selangor as it rules the state, along with the fact three districts of Selangor badly affected by the flood – Klang, Shah Alam and Hulu Langat – are all in the constituencies helmed by Pakatan MPs.
Read more on tropical depression and the worst flood in Selangor:
  • Let nature take its course means to allow something to happen without trying to control it, for instance when someone says the injury should heal within a few weeks if you just let nature take its course.
  • This might be an idiomatic expression but it really shows the operative principle in the way nature works.
  • If you let water in the river run its natural course, it will naturally end in the sea without overflowing its banks. No overflowed river means no floods.
  • But if you put unnatural obstacles along its course, it will swerve unnaturally around the obstacles and then once it has run past the obstacle, the water will continue its natural course to the sea.
  • However, the “vengeance” it left behind lies in its subsequent gradual slower movement as it nears the obstacle which will then build up into a bottleneck that will ultimately result in the overflowing of its bank at the affected area which in no time will then cause flood.
  • But what happens when the obstacles are natural ones, for example heavy rain?
  • When rain falls, some portion of it seep underground being absorbed by the forest and soil. The balance of the rainfall will be water flowing on the surface known as surface runoff, some of which will join the river that will continue its journey to the sea.
  • The balance of this surface run-off that is neither absorbed by the forest and soil nor join the river will end up at a dead end in freshwater swamps and lakes.
  • This is nature’s way of making lakes and swamps as a container or natural storage tank to accommodate the need for water to run its course, so that flooding will not occur.
  • But water also needs to occupy space. When it reaches a dead end of a flat surface, it will stay stationary on the surface but beneath it, it will force its way by burrowing minutely, patiently and very slowly the relatively hard surface where after hundreds or thousands of years a new lake or freshwater swamp will be created naturally.
  • Another aspect of water is it follows the pull of gravity in moving from a higher ground to a lower one. So, in flood mitigation project, it is very important water management takes into account all these natural aspects of water.
  • No more is this shown to be very successful than in the Netherlands where the Dutch who are very experienced in water management, having dealt with sea-level rise and river floods long before climate change became a concern, had turned previous flood mitigation efforts on their head.
  • While more than half the country lies beneath sea level, and the ocean is held back by more conventional flood control methods, the country’s river management has changed drastically.
  • In July, Dutch officials had celebrated the completion of a new flood control project, where instead of damming or diking the Maas River and its tributaries, as conventional flood control would do, they’d decided to work with nature – diverting the waters into a 1,300-acre flood plain created to duplicate the river’s old overflow channels.
  • In that month, as if to test the viability of the new “radical” approach, as soon as the new flood mitigation project was completed, Europe was hit by a deadly torrential rain.
  • Yet no one died in the Netherlands in that July flooding. Some tributaries did wreak extensive damage in the border region, but along the Maas River, which swelled to epic proportions, large urban centers stayed safe and dry.
  • The project, Maaspark Ooijen-Wanssum, a nature preserve near the small city of Wanssum, lies at the heart of the new approach, where the flooding did exactly what it was supposed to, absorbing so much water that levels in parts of the Maas River dropped by 13 inches (33 cm), enough to avert a major disaster.
  • Under this project, an old closed-off tributary of the Maas River was reopened along water paths used for thousands of years. Some dikes were removed to allow for water to flow in when necessary; others were placed strategically to send the water through natural channels. Several houses had to be destroyed to create more overflow space and, effectively, more nature.
  • If the area hadn’t been freed up for the nature preserve project to reroute the excess water from the Maas River, the nearby cities of Venlo and Roermond would have been flooded.
  • This project showed for a long time, river water management projects have worked against nature, when what the river is telling us is it needs more space.
  • The roots of this new thinking go back to two huge floods in the 1990s that forced the evacuation of hundreds of thousands of people.
  • Shaken by that disaster, Dutch officials and hydrologists eventually concluded with major floods occurring more frequently and with greater intensity, raising barriers and digging canals was no longer enough to manage the water.
  • They decided to give more space to the natural flows of major rivers, instead of increasing the height of the levees.
  • In 2007, the country began a US$2.7 billion (RM11.3b) project called Room for the River along the Maas and Rhine Rivers to control flood by creating catchment areas that often mimic the natural flood plains.
  • Since then, more than 30 such projects along the Maas and Rhine Rivers have been completed in which the catchment areas function like a natural huge tank that allows the river water to fill up space, thereby reducing the water level in the river by an amount enough to prevent a catastrophe.
  • Nearer home, in Bangkok the same approach of work with nature and give enough space for water to flow was applied in a flood mitigation project.
  • In 2017, an 11 acres land worth an estimated US$700 million was transformed into a lush, green oasis featuring ample space for outdoor meetings, an amphitheatre, a massive lawn for recreation, playgrounds, even a small museum.
  • Known as the Chulalongkorn University Centennial Park or simply CU Park, it also plays other important functions for the flood-prone city by collecting and cleaning water, thus reducing the urban heat island.
  • Its most amazing part is the ability to hold nearly one million gallons of water during severe floods because constructing the park effectively means creating a flood-proof park by building it to flood.
  • The park was designed in such a way as to sit at a gradual three-degree angle so that gravity pulls rain and flood water from the park’s highest point – the green roof – to the lowest point at the other end of the park, where rain and flood water fills a retention pond.
  • Three large tanks below the roof and museum can hold up to 250,000 gallons of runoff water from the green roof. During the dry season, rainwater in these tanks can keep the park watered for up to 20 days.
  • A lawn next to the museum also collects rainwater; its rounded, spoon-like shape can accommodate more than 105,000 gallons of water.
  • Rainwater also collects in four connected wetlands along the park, which contain a cascading series of dams and ponds. The wetlands feature native aquatic plants that clean and filter the water.
  • During mild rains, water flows through the wetlands and into the retention pond, where it gradually evaporates. In a fun and practical touch, park visitors can hop on stationary water bicycles along the pond, simultaneously exercising while keeping the water moving and adding oxygen to it.
  • But in case of severe flooding, the retention pond can nearly double in size by expanding onto the park’s porous main lawn. All together, the park is designed to hold up to one million gallons of water.
  • With the retention pond and lawns, the park can hold the floodwater even if the entire city is flooded. Eventually, water held by the park can be drained into the public sewage system when all the other flooding in the city has been drained.
  • Of course, a single small park can’t control flooding across an entire city. Its 11 acres represent just 0.003% of Bangkok’s footprint. But replicate this small park all over the city with this idea of let’s nature run its course and you’ll have a powerful formula on flood mitigation.
  • Malaysia would do well to emulate Holland and Thailand by adapting these nature-friendly projects to the local context such as weaving in the plant 100 million trees scheme into a flood mitigation projects by creating a series of nature preserves around Kuala Lumpur and Selangor that mimic the natural flood plains like the Dutch model.
  • Or a series of flood-proof parks by building it to flood in order to alleviate the rising water level of the rivers in Selangor during severe flooding as in the Bangkok model.
  • These projects won’t detract the original purpose of the 100 Million Tree-Planting Campaign launched in January or A Million Tree-Planting Campaign in the Federal Territories launched in April in making the country and the Federal Territory a low carbon, green city.
  • One other way to mitigate flood is the use of water absorbent roads which functions like the forest floor and soils where rainwater is naturally absorbed to the ground.
  • One negative consequence of urban development is the absorption rate of water to the ground is drastically reduced by the construction of paved roads and highways, which will only increase the rate of surface runoff causing flood resulting in submerged road.
  • But if the paved roads and highways are made of water absorbent materials, the scene of submerged roads during severe flooding may be a thing of the past.
Read more on the Netherland and Bangkok’s flood mitigation schemes, planting trees campaign and water absorbent roads:
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