This is a story about how we discovered that Jakarta, Indonesia’s capital city, is the fastest sinking city in the world. The sinking is so severe Dr Heri Andreas, a geologist who has been studying the phenomenon for 20 years now, said that 95% of the entire North Jakarta will be submerged by 2050 if the issue is left unaddressed. North Jakarta has sunk 2.5m in 10 years and is continuing to sink by as much as 25cm a year in some parts, which is more than double the global average for coastal megacities. Jakarta is sinking by an average of 1-15cm a year and almost half the city now sits below sea level. The city is home to 10 million residents, many of whom are experiencing the unseen consequences of the city’s sinking. The sinking, called land subsidence, is caused by the rapid groundwater extraction which occurs when Indonesians drill a pipe several hundred meters into the ground for fresh water. Many people in Jakarta do this, from individual home owners to entire shopping complexes or even whole office blocks, because of the city’s limited plumbing system. Most of them do it illegally too, by obtaining and installing pumps without informing the government. When you remove groundwater, the landmass above it begins to sink, almost as if it were sitting on a deflating balloon. This causes the the ground to separate from the foundations of buildings, compromising the structural integrity of entire structures which we saw at a local fishmarket that had foundational gaps as wide as 10 inches completely exposed. However the effects can also be far more subtle, like the tiny cracks that appear with increasing frequency at Fortuna’s bungalow in North Jakarta. Most residents, Fortuna included, just repaint over the cracks every few months and don’t pay it much attention but she tells BBC Indonesia that they’re very much aware that the cracks are caused by “shifts in the ground” beneath them. Fortuna’s indifference is how most people in Jakarta treat the issue of land subsidence – they know that there is something happening underground, some call it “shifts”, others like local fishermen we spoke to call it “natural changes” but no one ever attributes it to land subsidence. On top of that, the city’s sinking is also causing yearly floods in the city to worsen as well because the city now sits below sea level, making it more difficult for stagnant flood waters to flow out into the ocean. While the worsening floods are also caused by dirty rivers clogging up the city’s drainage and also rising sea levels, the land subsidence we see here is also exacerbating an already dire situation. Despite these circumstances, it is business as usual for property developers who continue to build and sell homes along the coast, the parts that are seeing the worst sinking, because they believe that they will continue selling so long as there is a demand. The property developers’ association (APERSI) added that they will not stop unless the government explicitly outlaws it. However the government itself is laxed in its enforcement. While Jakarta governor Anies Baswedan has acknowledge the issue, it has done little to stop illegal groundwater extraction as during an inspection last year, 33 of the 56 buildings it checked in Jakarta’s central business district was extracting groundwater illegally. At the time of writing, no action was taken against those using illegal pumps.
What makes this project innovative?
This was the first time a longform, interactive data story that was fully optimised for local internet speeds has ever been published in Indonesia. After our initial research, we quickly realised that the topic was far more complex than we initially thought as it involved several geological phenomenons that were unseen by the naked eye. For instance, most people knew something was happening underground but no one really understood how their own action of extracting groundwater to drink and cook with was causing this. Sometimes we had very visceral visual representations of this, like an office building that had to be abandoned because it’s entire first floor was now underground. However more often than not, the severity of the situation was lost on most Indonesians. So what we set out to do was really localise the issue to individual districts to help them visualise the sinking. That’s when we came up with the first component in the article - audiences could click on their district which would then show them how much their area had sunk up until 2017, along with a projection of how much more it could sink by 2025 and 2050. We faced several other challenges like the level of digital literacy in Indonesia. We had no data about online user behaviour here so we aimed to provide interactive components suitable for a variety of digital competencies so that everyone would be able to understand and interact with the story. That’s why we included a map showing the city’s overall sinking in 2017, with the option for people to click through to see projections in 2025 and 2050, while also ensuring that if someone didn’t know to click through, they would still be able to get information from the map as it stood. Additionally, because this was such a scientific topic, we also made a very simple and fun animation explaining land subsidence. Our biggest obstacle was probably poor internet speed here. Internet is slow, one of the slowest in the region, and internet is expensive so we spent the bulk of our time optimising the page to ensure that it provided people with the best experience at a small data cost, same goes with our core content. After several months, we were able to optimise the project to make it load fast on the 10mbps local mobile internet speed without having to make too many compromises. Even embellishments like the video at the top of the story, which lend to the overall style and story of the piece we managed to keep.
What was the impact of your project? How did you measure it?
We wrote this piece originally in Bahasa Indonesia but then adapted it into English as well. The Indonesian version saw just over 30,000 pageviews with 48 seconds retention rate. Thirty percent of the traffic was from Facebook while the rest were from Facebook searches, WhatsApp sharing and browsers. Ninety percent of the readers accessed the piece on a mobile device, with only 10% using a desktop. The video package and the explainer animation had a combined 280,000 views on YouTube. The English piece, on the other hand, had 3.8 million page views with an engagement time of 1:02. Fifty-three percent of the traffic came directly from loyal BBC readers either from the homepage or the BBC News app while some 45% was from social media. A surprising statistic was the fact that most of our social traffic came from emails or messaging apps, at a staggering 85% which tells us a lot of people were sharing this piece with their friends or colleagues. Numbers aside, this piece had massive impact both in Indonesia and around the world. In Indonesia, this was the first time a longform story with so many data visualizations and interactivity was published in a local language. This topic has also been written about previously by the likes of Reuters and the New York Times, but hardly ever were they published in Indonesia. This is why, we think, the piece triggered such discussion in Indonesia and was written about by all the major news outlets in Indonesia. A lot of the comments we saw were expressing their disbelief at the speed at which the city was sinking and questioning what the then-recently election Jakarta governor Anies Baswedan was doing about it. Mr Baswedan also, during a press conference soon after we published, attempted to dismiss the article as an exaggeration but stopped short of saying there were any inaccuracies or falsehood in the piece. The topic has also been brought up in one of the recent presidential debates ahead of the April 17 Indonesian elections. In English, the piece was read around the world both in English and after it was translated into at least 15 different languages. It again sparked conversation about the fact that many did not know how much Jakarta was sinking (most assumed it would be Venice). The piece also struck the interest of other news organizations, with our receiving requests for information from CGTN and a documentary team from Singapore.
Source and methodology
We began by reading anything and everything about land subsidence from research published by the Japanese government about Tokyo’s sinking back in the 1980s to news articles written by our competitors. Since this piece has been covered by other publications, we decided to delve into the data and present it in a new way using interactivity and data visualizations. We then got in touch with Dr Heri Andreas from the Bandung Institute of Technology who had been studying the phenomenon from 20 years. He gave us a lot of his research which we pored over and included in our story. However for the heatmaps, he wasn’t able to give us KML versions so we had to retrace it from stills. He also gave us the data for how much each province was sinking (in metres) for 2017, 2025 and 2050 which we cleaned in Google Spreadsheet and then used in both our interactive components. We then looked for the other subjects in our piece like Fortuna, local fishermen and Jakarta governor Anies Baswedan. It took us six months of research, 1 month of on-the-ground research (speaking to people in North Jakarta, looking for water pumps, setting up interviews with various local politicians, etc) followed by 2 months of production which involved writing the story, the sript to the animation, finalizing the interactives and then factchecking every single line in both the English and Indonesian versions. All in all, this project took 9 months as it required extensive research, development time for the interactives as well as to optimise the entire page, and later the editing process was also extensive as it was edited and vetted by at least a dozen senior editors in Indonesia, Singapore and London.
Authors: Mayuri MEI LIN, Rafki HIDAYAT Online production: Mayuri MEI LIN Animation: Davies SURYA UX & graphics: Arvin SUPRIYADI Development: Leben ASA Editors: Rebecca HENSCHKE, Samanthi DISSAYANAKE