Spatial and Time Series Modelling for the Groundwater Level of Peatlands in Riau and Central Kalimantan, Indonesia

Peatlands serve as vital carbon reservoirs, exhibiting two stability conditions. In a stable state, they absorb CO2 with slow decomposition. In contrast, an unstable state causes faster decomposition, leading to increased carbon emissions and a higher risk of peatland fires. Studies have found that carbon emissions positively correlate with lower water table depths, resulting in a higher emission rate. Considering peatlands’ behaviour, an autoregressive integrated moving average (ARIMA) model was used to predict the groundwater level in order to anticipate the risk of the unstable condition. The data taken was in Indragiri Hilir, Riau, and Pulang Pisau, Central Kalimantan, from 27 February 2021 to 18 March 2023. Furthermore, the Ordinary Kriging (OK) was used to estimate the groundwater level in the unobserved locations. Thus, the potential risk map of peatlands could be obtained. The forecasts showed that the groundwater level area decreased from March to May 2023, in line with the season change.