Mongabay–29 Jan: The daunting task of mapping Indonesia’s vast peatlands in painstaking detail has entered the home stretch, as competing proposals vie for selection as the standard to be adopted by the government.
Indonesia is home to the largest combined area of tropical peatland in the world, but lacks a comprehensive and detailed map of these carbon-rich landscapes that it needs to undergird a landmark policy of restoring degraded peatland and preventing the recurrence of annual fires across these ecosystems.
Peatlands are fast being drained and razed to make way for monoculture crops, primarily oil palms, in the process releasing massive amounts of greenhouse gases once trapped within the meters-deep layers of partly decomposed organic matter that comprise peat.
“That’s why peat maps need to be updated with the latest condition,” said Wiwin Ambarwulan, head of research at Indonesia’s Geospatial Information Agency, or BIG.
To that end, the presidentially appointed Peatland Restoration Agency (BRG) in 2016 announced a competition, the Indonesian Peat Prize, to find a fast, cost-effective and accurate mapping method for the country’s peat forests.
The competition has now been whittled down to the final five, and the winner will be announced in Jakarta on Feb. 2.
“We’re really anticipating the results of this competition because this problem of data accuracy is very important for our work,” said BRG deputy head Budi S. Wardhana. “The BRG’s mandate is only for five years. If we spend all of our time on mapping, when do we get to carry out the restoration work?”
The five finalists have proposed a wide range of mapping techniques, from using a device to measure the electromagnetic resistivity of peatlands, to integrating low-tech improvements to soil sampling methods with high-tech innovations in digital mapping based on the sophisticated processing technique of interferometric synthetic-aperture radar.
The technology that ultimately wins out will be adopted by the government as the standard for future peat mapping in the country, Wiwin said.
“We will implement it in all regions in Indonesia,” she said, adding “there’s a chance that we may combine technologies from two finalists.”
NO AUTHORITATIVE MAP
The vastness of Indonesia’s peatlands poses its own complexity. These landscapes are important for biomass production, water supply, carbon storage and biodiversity conservation. At the same time, their massive range means there are no authoritative maps clearly delineating peatlands from other areas, which has allowed them to be included in concessions for commercial exploitation, including plantations, logging and mining.
A 2016 presidential regulation, issued in the wake of devastating forest and land fires fueled largely by the burning of drained and degraded peat in 2015, bans companies from planting on peat that has been zoned for conservation. Plantation firms already operating in conservation areas can see their crops through for the duration of their life cycle, after which they cannot replant the land, but are required to rewet the peat for conservation purposes.
Currently, two peat maps among several in existence are the most commonly used: one produced by the NGO Wetlands International in 2004, and the other by the Ministry of Agriculture in 2011. In a 2013 report, the Dutch consultancy Deltares concluded that neither of these maps was suitable for spatial planning or policymaking, as both consistently underestimated the extent of the peatland and thickness of the peat layers.
The Ministry of Environment and Forestry also published a peat hydrological area mapin 2017, which divides peat zones into two categories: protection or production. The map uses data from various official maps, including that of the Ministry of Agriculture and one from the Ministry of Public Works.
But at a scale of 1:250,000, the Ministry of Environment and Forestry’s map is not detailed for use in effective spatial planning and policymaking tasks, which require maps with a finer resolution of 1:50,000.
This lack of an authoritative map and poor data has made it difficult for the government to identify peat areas that needed to be conserved — the necessary first step toward rehabilitating peatlands that have been degraded and rendered susceptible to fires.
COST CONCERNS
The government has experimented with the high-resolution mapping technique known as lidar, which functions similarly to radar — by beaming radiation toward the object being surveyed and measuring the reflected radiation — except it uses laser pulses rather than radio waves. While reliable and accurate, lidar’s main drawback is its high cost at about $700 per square kilometer ($1,810 per square mile). Indonesia’s peatlands span an estimated 149,000 square kilometers (57,529 square miles), around the size of New York, making this technique prohibitively expensive.
“It’s also still not enough because it can only cover the surface,” Budi of the BRG said. “So we can see the topography and identify land cover, but we can’t measure the depth [of the peat layer] even though the depth determines the management of peatlands, whether they’re for cultivation or to be protected.”
These limitations have left the BRG struggling to meet its target of mapping 104 peat zones in seven provinces. To date, it has only mapped seven peat zones using lidar and eight using traditional methods, which require multiple field observations and tacking on the costs. “We’re indeed struggling because it’s expensive,” Budi said.
That’s why, he said, the BRG is looking forward to settling on a proven and cost-effective solution and quickly adopting it as the national standard.
“We will submit the technologies to the Ministry of Environment and Forestry for them to improve their existing map,” Budi said.
