Hydrological disturbance is the main cause of increased fire susceptibility in Indonesia's peatlands. Due to this direct link, restoration of hydrology is considered to be one of the Central Kalimantan Peatland Project's major tasks. Canal-blocking is the most important practical tool to reduce drainage levels. Sound scientific knowledge forms the base of these activities.
Monitoring and modeling – understanding peatswamp hydrology
A good understanding of hydrological processes is pre-requisite for successful restoration of hydrology. The project gathers data on peatswamp hydrology and develops complex models to get insight in best practices of canal blocking and other restoration measures.
Data on weather, soil characteristics and water flows in the project area are constantly collected. They are used to get understanding of the area’s general conditions and to assess the impact of different hydrological measures taken in the past. The data also serve to construct a model that predicts how the system as a whole responds to future events like (repetitive) fires or restoration measures. Radar images provide important information as well. They are used to create a digital elevation model (DEM) which provides important insight in the area's spatial characteristics. This information is crucial for the understanding of hydrological processes at a catchment level.
These scientific insights will lead to optimal efficiency of activities undertaken in the field; among others they will aid the selection of locations for dam construction and the determination of the total number of dams necessary to restore the area's hydrology.
Construction of dams reduces drainage
Construction of dams in the many ditches and canals that traverse Kalimantan’s peatswamps is a promising method to reduce drainage. Small-scale damming activities performed in the past by different organizations have proven successful; the dams caused increased water retention, significantly decreasing desiccation of the peat layer upstream of the dam. Construction of dams is labour-intensive and expensive. Therefore it is very important to make a selection which of the hundreds of canals and ditches most urgently need to be blocked. Hydrological models combined with field measurements help to set priorities.
Raising awareness among local communities is a first step towards canal-blocking. Many canals are owned and operated by local villagers and intensively used for transport of forest products. To assure their full support it is important to explain the importance of canal blocks and to get permission of the canal owners. Only after this has been achieved, the blocking activities can be initiated. The project works with local communities to construct and maintain the dams. Local engineers developed appropriate techniques, which are largely based on traditional Dayak technology.
Alternative uses of the blocked canals are considered. Initial inventories indicate that they might be suitable for pond fisheries. As such they could provide an alternative source of income to local communities The project currently investigates to what extent this is sustainable and economically feasible.