Logo of Phnom Penh Post newspaper Phnom Penh Post - The NGO flying drones to map flooding

The NGO flying drones to map flooding

People in Need mapping officer Seng Buntheoun prepares a drone for takeoff in Stung Sen earlier this month.
People in Need mapping officer Seng Buntheoun prepares a drone for takeoff in Stung Sen earlier this month. Alessandro Marazzi Sassoon

The NGO flying drones to map flooding

In a freshly bulldozed lot in Kampong Krabao commune, across the Stung Sen River from Kampong Thom’s provincial capital, a team from the Czech NGO People in Need (PIN) is preparing a small Styrofoam drone for a survey flight. The flight is one of hundreds conducted throughout the country since August, with the aim of reducing preventable deaths from flooding through better mapping and an early warning system.

Sun Thun, a teacher at nearby Treal High School, recalls the last major flood to afflict the province in 2011 as “devastating”.

“Many people lost their houses and fields. The flood also destroyed livestock and killed people while tens of thousands did not have enough food or shelter,” he said, adding that schools were also flooded.

If residents had been informed sooner that a flood was coming, Thun said, it could have made a difference.

“As a citizen of the province, I hope the relevant authorities will be able to inform the people about the natural disaster in time, or beforehand so that they could prepare themselves,” he said. That’s a diagnosis People in Need had also made.

“A lot of flood deaths have been caused by a lack of information,” said PIN mapping officer Seng Buntheoun.

“People didn’t know when the flood is coming and where it will affect . . . [but] by measuring the elevation of the terrain, the changes [to the landscape], we can use the data to adjust the warning level accordingly,” he explained.

To that end, PIN has partnered with the provincial and national committees for disaster management in Kampong Thom as well as Kampong Chhnang, Battambang, Pursat, Kratie, Stung Treng, Siem Reap and Banteay Meanchey provinces to overhaul the way the government anticipates and reacts to floods.

According to data compiled by the National Committee for Disaster Management (NCDM), 47 percent of deaths due to natural disasters are caused by flooding, numbering 1,150 since 1996. Flooding has been responsible for destroying or damaging nearly 34,000 homes in that time, and for countless more evacuations. Just last year in Kampong Thom, flooding damaged some 1,300 houses.

Content image - Phnom Penh Post

According to NCDM spokesman Keo Vy, while the province has been spared from major flooding since 2013, it remains one of the most vulnerable regions in the country.

“Kampong Thom, due to its geographical location, is very vulnerable to floods,” he said, noting “water levels have usually risen close to the warning point over the past four years”.

Since 2013, PIN has been scaling up an automated flood warning system over cell phone networks, and last year they began installing sonar-based water level gauges that ping information directly to local authorities, further streamlining the process of notifying residents by phone.

According to Vy, some 70,000 people have registered to use the phone service across 10 provinces.

One such gauge was installed by PIN this month on the Stung Sen Bridge, which could reduce the time it takes for authorities to warn the public from a matter of hours or days to just a few minutes.

Now PIN is flying two $10,000 drones equipped with 18-megapixel cameras to create 3D topographic maps that will for the first time provide authorities with knowledge of how an area will be flooded.

Back on the lot, mapping officer Buntheoun has charted the automated flight path for the day’s survey on a laptop, hooked up to a mobile GPS base. Holding the two-kilogram drone by its wings, he gives it a shake, a propeller begins to whirr, and he launches it into the air like it’s a jumbo paper plane.

“Today we’re mapping about 1.2 square kilometres,” he said. Every few seconds the computer clicks – another photograph received from the camera on the drone’s underbelly.

“The GPS base sends a GPS signal to the drone to give a more precise signal that is accurate to 2 to 3 centimetres,” he explains.

Content image - Phnom Penh Post
The Stung Sen Bridge, which was recently outfitted with a gauge to detect water levels and notify residents of flood risks. Alessandro Marazzi Sassoon

That accuracy, he says, is reflected when the photographs are run through a modelling program that transforms them into a 3D map. The result is a far cry from the maps currently used from 2011, which are outdated and imprecise.

“It’s far more detailed than the old data where the length of each pixel was [equal to] 30 metres. Here it’s four centimetres,” Buntheoun said. “It takes into account landscape changes such as building construction . . . Effects are different from how water will react to a rice paddy versus an urban establishment.”

Heng Sarith, a member of the Kampong Thom provincial committee for disaster management said the updated maps will be a “great” help.

“It shows which areas are the most vulnerable to natural disasters, and which areas are the least affected,” he says.

After 20 minutes, the drone flying overhead comes in for a landing, its battery is swapped out and then it is quickly back in the air. Taken from 200 metres above ground, the pictures will be stitched together, creating a mosaic of the area, and of its vulnerabilities.

Residents living in flood-prone areas can call 1294 for free to subscribe to the flood alert information system.

MOST VIEWED

  • Cambodia armed with money laundering laws

    Money laundering will now carry a penalty of up to five years in prison while those convicted of financing terrorists will be jailed for up to 20 years, according to new laws promulgated by King Norodom Sihamoni and seen by The Post on Thursday. Comprising nine

  • Schools to be reopened in ‘three stages’

    With guidance from Prime Minister Hun Sen, the Ministry of Education, Youth and Sport, is in the process of reopening schools in three stages. But no timeline has been set, ministry spokesperson Ros Soveacha said on Thursday. Soveacha said the first stage will be to

  • Thai border crossings eased

    The Cambodian Embassy in Thailand said in an announcement on Wednesday that Thailand’s government has allowed certain passengers from several countries to enter its borders. The visitors must go back to their country immediately after their duties in Thailand are fulfilled, the embassy said.

  • Gov’t says tourism recovers slightly despite pandemic

    The Ministry of Tourism and the Phnom Penh municipal administration have recognised 33 tourism businesses in the capital which have consistently implemented safety measures for tourists and adhered to the code of conduct issued by the ministry. Recently, the ministry announced that tourism businesses had to

  • Mull ASEAN border opening, PM urges

    Prime Minister Hun Sen has requested that ASEAN launch a scenario for gradually reopening cross-border travel and trade between countries in the region. He said ASEAN has had more success combating Covid-19 compared to other regions. The prime minister’s request was made at the

  • Ministry reports 11 new Covid-19 cases, reiterates vigilance

    Minister of Health Mam Bun Heng has urged people to continue practising virus prevention techniques after 11 people tested positive for Covid-19 within two days after arriving in the Kingdom. Speaking on Sunday, Bun Heng stressed the importance of washing hands, wearing masks or scarves when

  • Nine on Indonesia flight Covid-19 positive

    The Ministry of Health on Saturday confirmed nine more imported cases of Covid-19. The nine ‒ eight Cambodians and one Indonesian, aged 22 to 26 ‒ arrived in Cambodia on Thursday via a direct flight from Indonesia and are receiving treatment at the Khmer-Soviet Friendship Hostipal in Phnom Penh.

  • Kingdom’s financial sector healthy

    Cambodia's financial sector remains on a sustainable growth path despite the Covid-19 pandemic squeezing crucial industries, National Bank of Cambodia (NBC) governor Chea Chanto said. Tourism, garments and footwear have borne the brunt of the Covid-19 impact, he said, whereas the financial and agriculture sectors

  • Vietnam told to remove border tents

    Kandal provincial governor Kong Sophoan has ordered local authorities to prohibit the construction of buildings in areas bordering Cambodia and to report any irregularities immediately. Recently, Vietnamese officials removed another seven tents from the border area with Cambodia. His remarks were made on Wednesday afternoon

  • Migrant workers set to return from Malaysia

    The Ministry of Foreign Affairs and International Cooperation confirmed on Thursday that 158 Cambodian students and migrant workers will fly home from Malaysia on Friday morning. This is the second flight to bring Cambodians home from Malaysia. A ministry notice said Malaysia Airlines Flight MH754 will