A process-based model for quantifying the effects of canal blocking on water table and CO₂ emissions in tropical peatlands

Abstract. Drainage in tropical peatlands increases CO2 emissions, the rate of subsidence, and risk forest fires. To a certain extent, these effects can be mitigated by raising water table depth (WTD) using canal or ditch blocks. The performance blocks WTD is, however, poorly understood because monitoring data are limited spatially concentrated around canals This raises following question: how effective over large areas? In this work, we composed process-based hydrological model to assess peatland restoration 168 22 000 ha area Sumatra, Indonesia. We simulated daily 1 year an existing block setup compared it situation without study was performed across two contrasting weather scenarios representing dry (1997) wet (2013) years. Our simulations revealed that, while had net positive impact on rise, they lowered some areas, extent their effect distance about 600 m canals. also show that most with high hydraulic conductivity. Averaging all modeled scenarios, raised annual mean only 1.5 cm. value similar (1.44 cm) (1.57 years, there 2.13 fold difference between small conductivities (2.05 cm versus 0.96 cm). Using linear relationship estimated averaging peat properties, prevented emission 1.07 Mg ha−1 1.17 year. believe modeling tools developed work could adopted local stakeholders aiming at more evidence-based approach canal-block-based restoration.