Even though the national government has put policies into places, the burning are still taken place. The massive burning in 2015 made the Indonesia president, Joko Widodo to launch the policies aimed at preventing future fires by restoring peatlands and conserving forests.
The long-term problem of peat-swamp forests in Indonesia is drainage, the construction of canals and channels inside the forest that causes the peat to dry out and increases the fire risk values. Most peat-swamp forests are now protected under the Indonesian government's moratorium, but they remain threatened by illegal logging.
To keep peat soils resistant to fires, the water level has to be maintained at or above the level. If the peat is drained out, oxidises and degrades, the whole ecosystem is at risk of fires. The peat surface will crumble and little water is retained in the peat during the dry season. Dried peat is flammable and can catch fires easily. Once the fires happen, they will be difficult to extinguish.
Blocking canal will slow the rate of dry season drawdown and retain water in the system leading to keep peat wetter and longer. The dammed canals are monitored regularly by measuring water flow rates and water tables.
The Peatland Restoration Agency (BRG) is in charge of blocking the drainage canals and rewetting peatlands. However, according to the Forestry Department officials in Riau, simply built an infrastructure is not enough, Indonesia needs to have enough budget or resources to maintain it. Various infrastructures have been built to restore peatlands such as deep wells or canal blocking; however, without proper funding, the infrastructures are easily destroyed, especially by disapproving villagers. To build the canal system, the authorities must first obtain the approval from local residences whose their lives will be affected.
It is very crucial for the projects to maintain both wetness of peatlands to prevent the fires and secure local people's approval since they use the canal for transportation.
CANAL BLOCKING
Canal blocking definition :
A water weir ( dam ) that is installed in canal or ditch body aims at reducing run off and to retaining water within canal / ditch body and its surrounding areas.
Canal blocking working principle :
Retaining water and storing water as much and long as possible with peatland hydrological unit (PHU)
1. Based on construction age :
-Short term ( Temporary)
-Medium term ( Semi-permanent )
-Long term ( Permanent )
2. Based on main structures and construction materials
-Wooden dam ( single sheet / plank dam / multi-sheet piles
-Soil bags
-Rock
-Compacted peat
-Concrete
-Gabians
-Pre-cast
-Water gates
Wooden dam ( two-sheet piles ) ( non-spillway )
Wooden dam ( two-sheet piles ) ( non-spillway )
Compacted peat dam
Goal ;
To reduce run-off and increase water retention in the canals and its adjacent site
Design ;
Single, multi-sheet piles box dams, soil bags, compacted peat, gabions, rock, pre-cast, water gates, etc.
Structure materials ;
wooden, concrete, plastics, etc.
Infill materials ;
mineral / alluvial soils, high decomposed peat ( sapric, hemic )
CANAL BACKFILLING
Canal Backfilling definition :
One of the rewetting techniques where open drained canal or ditch is refilled with on-site organic peat and / or coarse organic materials ( tree branches, stems, leaves, etc. ) so that the canal / ditch will be shallowed and sedimented thereby the water drainability rate of the canal / ditch is reduced (Houterman and Ritzema, 2009; Applegate dkk, 2012; Dohong, A, 2016) .
Canal backfiling goal:
Water conservation through the increase of water shallowness and sediment of the canal/ditch body so its drainability can be reduced and water retention can be increased within canal/ditch body and its surrounding areas
Model design canal backfilling #1
Model design canal backfilling #2
Model design canal backfilling #3
Goal ;
To increase sedimentation in the canals so that its drainability can be reduced
Design ;
Partly segments of the drained canals are infilled ( 100-300 m ) for certain interval ( every 1 km )
Infill materials ;
Peats from berms, coarse on-site organics materials ( death woods, tree branched, stems, etc. )
DEEP WELL
Well under construction
Source : https://iphc.org/ptp/2013/05/21/water-well-completed-in-indonesia/
Well under construction
Source : https://iphc.org/ptp/2013/05/21/water-well-completed-in-indonesia/