of canal blocking and deep wells as well as conducted canal backfilling throughout
the seven provinces as part of its effort to rewet the drained peatland.
20.3.2 Techniques for Restoring Peatland Hydrology
Currently, there are two major techniques that have been implemented to improve
the hydrology of drained peatland in Indonesia (Dohong et al. 2018). The two
techniques are canal blocking and canal backfilling.
20.3.2.1 Canal Blocking
Canal or ditch blocking is one of the rewetting techniques implemented by putting
dams or water weirs in the drained canal course to reverse the surface water outflow
and raise the surface water level in and along the canal course as well as the GWL
adjacent to blocked canal (Dohong and Lilia 2008; Ritzema et al. 2014; Suryadiputra
et al. 2018; Dohong et al. 2018).
The typical dam design and its technical specification heavily depend on several
factors such as the expected technical life expectancy of the dam, size of the dam,
and availability of materials on-site (Dohong et al. 2017b).
For small and narrow channels, a simple dam design such as the single or
composite plank blocking can be applied and adequate materials for building said
dams are normally locally available (Fig. 20.1).
Simple and small single wood-composed dams are commonly used to block small
canals dug by illegal loggers in peat swamp forest area or small ditches for draining
small scale agricultural area.
Further, for canals of large dimension which are normally built at the large-scale
agricultural irrigation or industrial timber plantation, stronger and more complex
dam design and technical specifications should be used. The said dam can be made
from strong wood, concrete, gabions, and precast concrete. Examples of those dams
are presented in Figs. 20.2, 20.3, and 20.4.
20.3.2.2 Canal Backfilling/Canal Infilling
Canal backfilling is one of the rewetting techniques conducted by infilling artificial
drainage body with peat materials and wood debris (tree branches, dead stems, etc.)
available at the canal banks or nearby to shallow and promote the sedimentation
process in the canal course, and thus, its drainablity can be reduced (Dohong et al.
2017b). The long-term goal of canal backfilling is the creation of swampy areas
along the canal course. Hence, along with canal backfilling, active revegetation as
well as natural regeneration on top of the filled canal should be carried out to
accerelate the recovery of the peatland hydrology.
572
A. Dohong and L. Tanika
the seven provinces as part of its effort to rewet the drained peatland.
20.3.2 Techniques for Restoring Peatland Hydrology
Currently, there are two major techniques that have been implemented to improve
the hydrology of drained peatland in Indonesia (Dohong et al. 2018). The two
techniques are canal blocking and canal backfilling.
20.3.2.1 Canal Blocking
Canal or ditch blocking is one of the rewetting techniques implemented by putting
dams or water weirs in the drained canal course to reverse the surface water outflow
and raise the surface water level in and along the canal course as well as the GWL
adjacent to blocked canal (Dohong and Lilia 2008; Ritzema et al. 2014; Suryadiputra
et al. 2018; Dohong et al. 2018).
The typical dam design and its technical specification heavily depend on several
factors such as the expected technical life expectancy of the dam, size of the dam,
and availability of materials on-site (Dohong et al. 2017b).
For small and narrow channels, a simple dam design such as the single or
composite plank blocking can be applied and adequate materials for building said
dams are normally locally available (Fig. 20.1).
Simple and small single wood-composed dams are commonly used to block small
canals dug by illegal loggers in peat swamp forest area or small ditches for draining
small scale agricultural area.
Further, for canals of large dimension which are normally built at the large-scale
agricultural irrigation or industrial timber plantation, stronger and more complex
dam design and technical specifications should be used. The said dam can be made
from strong wood, concrete, gabions, and precast concrete. Examples of those dams
are presented in Figs. 20.2, 20.3, and 20.4.
20.3.2.2 Canal Backfilling/Canal Infilling
Canal backfilling is one of the rewetting techniques conducted by infilling artificial
drainage body with peat materials and wood debris (tree branches, dead stems, etc.)
available at the canal banks or nearby to shallow and promote the sedimentation
process in the canal course, and thus, its drainablity can be reduced (Dohong et al.
2017b). The long-term goal of canal backfilling is the creation of swampy areas
along the canal course. Hence, along with canal backfilling, active revegetation as
well as natural regeneration on top of the filled canal should be carried out to
accerelate the recovery of the peatland hydrology.
572
A. Dohong and L. Tanika