Assessment of Dissolved Organic Carbon Fluxes from Rivers in Sarawak, Borneo Using Satellite Remote Sensing

Tropical peatlands are substantial long-term carbon deposits. The future conservation of these systems is threatened due to land change and significant peatland draining. This has the potential to transform more carbon deposits into carbon sources in the form of total organic carbon (TOC) and carbon dioxide (CO2) gas. Total DOC fluxes from the 3 basins (Rajang, Sadong and Lundu) are significantly representing 0.1% of the global annual riverine and estuarine DOC flux, despite the fact their water area covers only 0.05% of the global river/estuarine area. With this new method to estimate DOC flux in the coastal waters, we are able to study the effect of land cover and land use (LCLU) change on the DOC flux from 2001 to 2018. We found out, basin with higher percentage of disturbed peatland will have higher percentage increase of DOC flux. Therefore, basin with higher percentage of peatland is more sensitive to oil palm expansion.