investments or they are afraid that new water level management techniques might
result in lower oil palm production. Since it is clear that current their water management practices have been causing peat destruction, their decisions are obviously
incorrect when considering the medium- to long-term future.
Currently, most industrial forest companies have learned about the importance of
responsible water management in peatland and started to improve their management
system to keep water from flowing from the upper to the lower side by canal
blocking (peat dam). However, improvement is not easy to attain when the former
water management system is outdated and conventional.
As mentioned above, a full understanding of peatland hydrology is required.
Thus, companies should prepare a peatland management plan before starting their
operations in peatlands. If possible intensive and comprehensive data such as
topography, peat distribution, peat depth, and peat characteristics (for details, see a
later section) are needed for the plan. These data will be useful for companies that
wish to improve their water management.
3.6 A New Concept of the Water Management System
A proper water management, “Stock-based water management,” is an important
aspect of the strategies for action at multiple levels, between local communities,
national, and international levels, in hydrological restoration on tropical peatlands.
WSL-MTI considered the peat ecosystem (or landscape) as a whole series of peat
domes with a variety of sizes, and then focused on the hydrology of the individual
peat dome. Since peat domes are ombrotrophic peats, the seasonal GWL variation is
predominantly determined by the balance between rainfall and evapotranspiration
and the discharge of peat dome edges (Brady 1997).
Thus, the key to responsible water management is to maintain the overall water
balance (or budget) of a peat dome, which is accountable for the inputs, outputs, and
storage within the peat dome. It seems simple in theory; however, implementing
water management is extremely difficult in practice, especially when adjusting to
spatial and temporal variabilities affected by microtopography, rainfall, temperature,
peat depth, peat characteristics, groundwater, and others.
Taking the water balance of the peat dome into account, WSL-MTI aimed to
develop a new water management system based on the following principles: the first
is to maintain the groundwater of the peat dome at a constant level for the entire area
throughout the year; the second is to prevent peat fire with high soil moisture
content; the third is to boost tree growth on peat; and the fourth is to conserve the
native ecosystem as much as possible. Furthermore, as mentioned earlier, WSL-MTI
decided to start an industrial forest plantation on degraded peatlands, which had lost
economic value due to past commercial, illegal logging, and slash-and-burn agriculture. To prevent further destruction of the peat ecosystem and the forest/peat fire,
WSL-MTI had studied in detail the hydrology of peatlands by referring to past
examples in addition to field surveys on peat and vegetation. WSL-MTI have
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T. Kato et al.
result in lower oil palm production. Since it is clear that current their water management practices have been causing peat destruction, their decisions are obviously
incorrect when considering the medium- to long-term future.
Currently, most industrial forest companies have learned about the importance of
responsible water management in peatland and started to improve their management
system to keep water from flowing from the upper to the lower side by canal
blocking (peat dam). However, improvement is not easy to attain when the former
water management system is outdated and conventional.
As mentioned above, a full understanding of peatland hydrology is required.
Thus, companies should prepare a peatland management plan before starting their
operations in peatlands. If possible intensive and comprehensive data such as
topography, peat distribution, peat depth, and peat characteristics (for details, see a
later section) are needed for the plan. These data will be useful for companies that
wish to improve their water management.
3.6 A New Concept of the Water Management System
A proper water management, “Stock-based water management,” is an important
aspect of the strategies for action at multiple levels, between local communities,
national, and international levels, in hydrological restoration on tropical peatlands.
WSL-MTI considered the peat ecosystem (or landscape) as a whole series of peat
domes with a variety of sizes, and then focused on the hydrology of the individual
peat dome. Since peat domes are ombrotrophic peats, the seasonal GWL variation is
predominantly determined by the balance between rainfall and evapotranspiration
and the discharge of peat dome edges (Brady 1997).
Thus, the key to responsible water management is to maintain the overall water
balance (or budget) of a peat dome, which is accountable for the inputs, outputs, and
storage within the peat dome. It seems simple in theory; however, implementing
water management is extremely difficult in practice, especially when adjusting to
spatial and temporal variabilities affected by microtopography, rainfall, temperature,
peat depth, peat characteristics, groundwater, and others.
Taking the water balance of the peat dome into account, WSL-MTI aimed to
develop a new water management system based on the following principles: the first
is to maintain the groundwater of the peat dome at a constant level for the entire area
throughout the year; the second is to prevent peat fire with high soil moisture
content; the third is to boost tree growth on peat; and the fourth is to conserve the
native ecosystem as much as possible. Furthermore, as mentioned earlier, WSL-MTI
decided to start an industrial forest plantation on degraded peatlands, which had lost
economic value due to past commercial, illegal logging, and slash-and-burn agriculture. To prevent further destruction of the peat ecosystem and the forest/peat fire,
WSL-MTI had studied in detail the hydrology of peatlands by referring to past
examples in addition to field surveys on peat and vegetation. WSL-MTI have
98
T. Kato et al.