Drainage canals have triggered peat subsidence and lowered groundwater table, enabling wildfires and peat degradation in Riau, Indonesia. This study examines the changes on groundwater table, peat subsidence rate, and carbon emission in response to deforestation and land cover changes. We established 31 study sites in some land cover types (i.e., oil palm plantation, acacia regrowth and shrub), with 124 monitoring shallow wells and 31 subsidence poles that were setup and have been monitored for 18 months. Groundwater table of all plots averaged -55 cm in Dosan Village, higher than that in Dayun Village (-66 cm). In accordance, peat had subsided in faster rate (8.4 cm year−1) in Dayun Village than that in Dosan (3.3 cm year−1). This average annual groundwater table has resulted in carbon emissions from peat decomposition up to 66 t CO2eq ha−1 year−1. On the other hand, canal discharge of these sites ranged from 2 to 73 dm3 s−1, averaging 26 dm3 s−1. These results evidence that land uses converted from peat forest, and the dimension of canal control the decrease in groundwater table, the pace of peat subsidence, and rate of carbon emissions in tropical peatlands.

One of Indonesia’s regencies known for its agricultural land is Sukoharjo. The shortage of irrigation water has caused many problems in past years. The purpose of the research was to better understand the subsurface structure to increase the effectiveness of drilling in deep groundwater. Schlumberger’s configuration with a deep aquifer irrigation target zone was used to conduct the investigation. The track’s length is between 275 and 300 meters. Information obtained about the depth of the aquifer zone in the southern part of Sukoharjo is estimated to range from 4.83 to 155.79 meters. In the southern part of Sukoharjo, most of the ground cover consists of layers of sediment, limestone, and sandy clay.

Sukoharjo is one of the regencies in Indonesia that is famous for its agricultural land. Sukoharjo itself has 12 sub districts spread evenly throughout. In recent years, there have been many conflicts of irrigation water shortages for agricultural land. Therefore, research was conducted on the aquifer zone of the southern district of Sukoharjo. The research was conducted by Vertical Electrical Sounding method to determine the structure of soil in order to improve the efficiency of deep groundwater drilling for irrigation. The study used Schlumberger’s configuration with a target zone of deep aquifers for agricultural irrigation. The length of the track used is 275-300 meters. As a result of the study, it is suspected that the aquifer zone in southern Sukoharjo Regency has a depth of about 11.54-83.93 meters below the subsurface. The soil structure in south of Sukoharjo is dominated by sandy clay layers, limestone layers, and sedimentary layers.