Groundwater level fluctuations in peatlands as responses to canal block construction in Sungai Tohor, Tebing Tinggi Island, Indonesia

Abstract

Peatlands play an essential role in an ecosystem and generally have three main functions, e.g., a buffer zone in a water system. However, they are vulnerable and susceptible to environmental changes. In response to the increasing demand for habitable space, more peatlands have been converted to productive agricultural land by canal blocking to transform an originally anaerobic environment into an aerobic one. This condition also occurs in peatlands in Sungai Tohor, Tebing Tinggi Island, Kepulauan Meranti Regency. This study sought to determine the groundwater level fluctuations in peatlands after the construction of canal blocks by the Peatland Restoration Agency (BRG). A water level logger was installed at the monitoring well, and the daily groundwater levels were observed for one year. The results showed that the groundwater levels fluctuated from 8.78 m (the lowest) to 9.72 m (the highest), with an average of 9.21 meters. This means that canal blocking might have a sufficient wetting impact, i.e., maintaining the presence of water in the surrounding peatlands.