Indonesian Peatland Map: Method, Certainty and Uses
Peatland map has a strategic significance in agricultural development planning, land conservation and calculating green house gas (GHG) emissions. This study aims to improve the accuracy of the Indonesian peatland map at scale 1:250.000 through an overlay of old version peatland map (Wahyunto et al. (2003, 2004, 2006) with legacy soil data and current soilsurveys data. Approximately 2.409 site observations equipped with recording of geographical positioning System (GPS) including peat thickness and peat maturity observations used in this study. The main land cover types on peatland (such as: forest, oil palm, shrubs-bush, annual agricultural crops, horticulture crops, tree crops/fruits and paddy fields) were also mapped.
The results showed that the latest Indonesian peatlands based on legacy soil data resulted from soil survey up to the year of 2011 was approximately 14,9 M ha, mainly distributed into 3 islands namely Sumatra, Kalimantan and Papua. A lot of decreasing areas from the original estimate total of 20,6 M ha previous peatland area during 9-year period (2002's to 2011), peatlands of Sumatra and Kalimantan islands successively reduced approximately 0,7Mha and 1 M ha.. While in Papua island peatland estimated was reduced about 4.4 million ha from the old estimate of 8 million ha, because the previous estimate mostly based on analysis of satellite images with limited ground truth data. By the support of 2.409 observation points the level of confidence is much higher compared to the previous version. From the total peatland area, a 2011 landsat TM imagery analysis showed that 7.8 Mha (50.1%) is covered by forests, 1.56 Mha (10.5%) oil palm plantation, 0.79 Mha (5.7%) annual agricultural crops and 0.3 Mha (2.3%) paddy field.