Bangkok is sinking.
Stretching within the delta of the Chao Phraya River, the capital of Thailand was once often known as the Venice of the East because of its network of canals. Today, because of rapid development, lots of these waterways have been full of cement.
Bangkok, with nowhere for water to flee, became known for frequent, devastating floods, sometimes occurring after just half-hour of rain. The reality is that this city of 20 million people, built on shifting river silt, is sinking at a rate of over one centimeter per yr, and may very well be below sea level as early as 2030.
Thai landscape architect Kotchakorn Voraakhom, a TED Fellow, has seen her city turn right into a dense concrete jungle together with her own eyes. “When I was young, there were rice fields and canals in the city,” she recalls.
“I heard the boats from my house in downtown Bangkok. Now all these fields and canals have been blocked with concrete and covered with skyscrapers. All buildings and concrete become obstructions to water drainage, resulting in flooding in the city.”
At his Bangkok-based company Landprocess, Voraakhom designs parks, gardens, green roofs and bridges that solve town’s flooding problem while reconnecting residents with their natural environment. “We spend too much time in buildings,” he says. “I believe it is vitally vital for us as urban planners to have places where we are able to reconnect with our nature, with Mother Earth. Just to see the sky.
Voraakhoma’s latest accomplished project is a stunning park in central Bangkok, situated on the campus of Chulalongkorn University.
She transformed 11 acres of town – land price an estimated $700 million – into Chulalongkorn University Centennial Park, a lush, green oasis with ample outdoor gathering space, an amphitheater, an enormous lawn for recreation, playgrounds and even a small museum.
Since opening in March 2017, the park has been extremely popular with students and locals (one local podcast called it a “hidden gem”). And while 11 acres (or 44,415 square meters) may not look like rather a lot, any latest park in green-starved Bangkok is a giant deal. According to the Siemens Green City Index, there is barely 3.3 m2 of green space per person in Bangkok (in comparison with 5 in Manila, 11 in Paris, 13.5 in Shanghai, 23.1 in New York, 27 in London, 66 in Singapore).
But CU Park also serves other necessary functions for a flood-prone city: it collects and purifies water and reduces the urban heat island. The most amazing a part of CU Park? During severe floods, it might hold nearly 1,000,000 gallons of water.
(For comparison, a million gallons is akin to completely filling an American football field with water at a depth of 1.13 meters, or 3.71 feet). Basically, Voraakhom created a flood protection park constructing it in order that it’s flooded.
When designing the park, Voraakhom had two important inspirations: the rain tree and the monkey’s cheeks.
Chulalongkorn University, the oldest university in Thailand, opened the space on the occasion of its a centesimal birthday. So when Voraakhom began her initial designs, she turned to the university’s symbol: rain tree.
“It has a very significant, far-reaching root system, and the branches reach too far, creating shade and ecology for the surroundings,” Voraakhom says. “This park is a metaphor for creating this great rain tree for society. We want this green infrastructure to grow like a tree root towards the city.”
To mimic the extensive branches and water-absorbing roots, Voraakhom added green paths along a busy road that runs perpendicular to the park.
It enlarged the road from 12 meters to 30 meters, but actually reduced automobile lanes and replaced them with cycle paths and adequate sidewalks – something unheard of in Bangkok. (In fact, she believes her park is the primary time a important road in Bangkok has been converted from traffic lanes to walking paths). Pedestrians and cyclists now gather within the cool shade of the tree-lined paths that emerge from either side of the park.
Now about those monkey cheeks. King Bhumibol, Thailand’s monarch from 1946 until his death in 2016, often used the metaphor of monkey cheeks to explain how Bangkok could adapt to flooding.
He said that just as a monkey holds food in its mouth until it feels the necessity to eat, Bangkok should give you the chance to carry flood water until town can use it. This concept inspired Voraakhoma to construct water-retention features within the park: a green roof, wetlands, a lawn and a retention pond.
CU Park cleverly uses the force of gravity.
Voraakhom designed her park to be at a gradual three-degree angle in order that gravity would pull rain and water from the park’s highest point – the green roof – to the bottom point on the far end of the park, where it filled a retention basin.
The park has the most important green roof in Thailand.
At the western end of the park, a 5,220-square-meter green roof covers the brand new CU Park Museum. A roof covered with native grasses and weeds requires little maintenance; it’s each strong enough to soak up large amounts of water in the course of the rainy season from July to October and sturdy enough to survive the recent season from March to June.
Voraakhom’s favorite spot in the complete park is the green roof, which rises to a height of 10.5 meters. “Normally Bangkok is so flat that you don’t feel like you’re up when you walk to the park,” he says. “But here, when you go up on the green roof, you see a new view of the city and it’s a completely different experience. Even though I was born here and have lived here all my life, it is still a very surprising view of Bangkok.”
The storage tanks are hidden under a green roof.
Three large tanks under the roof and museum can hold as much as 250,000 gallons of water flowing off the green roof. During the dry season, the rainwater contained in these reservoirs can provide water for the park for as much as 20 days. “Not a single drop of water that falls into the park will be wasted,” says Voraakhom. The lawn next to the museum also collects rainwater; its rounded, spoon-like shape can hold over 105,000 gallons of water.
Wetlands filter water and create space for youngsters to explore.
Rainwater also collects in 4 interconnected wetlands along the park, which feature a cascading series of dams and ponds. Wetlands are home to native aquatic plants that purify and filter water and supply shelter for youngsters. “Children love playing in these spaces where they can directly interact with nature,” says Voraakhom.
University students even have many good reasons to spend time on the park. There are eight outdoor seating areas along the edges of the park, in addition to a herb garden and an amphitheater. “Chulalongkorn University is the largest and oldest university in the city, just like Harvard in Bangkok,” says Voraakhom. “Therefore, the park must serve the university community for large events such as commencements, as well as provide a place for recreation and exercise for surrounding communities.”
During mild rainfall, water flows through wetlands to a retention reservoir, where it progressively evaporates. In a fun and practical way, park visitors can hop on stationary pedal boats along the pond while exercising by keeping the water moving and adding oxygen to it.
However, within the event of a severe flood, the retention reservoir can almost double in size, extending into the park’s porous important lawn.
In total, the park is anticipated to carry up to 1 million gallons of water. “With a retention pond and lawns, we can hold flood water for as long as we want if the entire city floods,” Voraakhom says. “Then we can finally empty the park into the public sewer system once all the other floodwaters in the city have been drained.”
Source: https://ideas.ted.com/when-bangkok-floods-and-it-floods-a-lot-this-park-does-something-amazing/
