Principles of developing a water management strategy for a peat deposit based on the Klias Forest Researve and surrounding areas

Greer T., . and Wollesen L., . and Matunjau C, . and Yap S.F., . (2005) Principles of developing a water management strategy for a peat deposit based on the Klias Forest Researve and surrounding areas. [Proceedings Paper]

The Klias peat deposit is characterised by a dome shape; being higher in the centre and north with the deposit sloping away to the edges and the south. The deposit is a contiguous hydrological unit. Hydrological change in one part of the unit will ultimately affect the rest of the unit. Occupying the central and topographic high of the dome is the Klias Forest Reserve which currently provides protection to the last remaining freshwater peat swamp forest of this type in Sabah. To either conserve or utilise a peat dome requires the management of each dome as a single hydrological unit as the water table in each deposit is contiguous. Contrasting uses within a single unit are likely to lead to conflicts wich although manageable in the sort term are unsustainable in the long term. The single greatest threat to any peat deposit undergoing development is subsidence. The initial rapid phase of subsidence takes place immediately after forest removal when the previously wet forest floor is opened up and oxidation takes place this phase reportedly lasts for a year or two. Thereafter subsidence continues albeit at a slower rate in proportion to lowered water levels a requirement of most agricultural development. Current knowledge and findings elsewhere in Malaysia state that even with improved water management subsidence cannot be halted. Ultimately the peat with disapear although this will depend upon the depth of the peat and will be on the time scale of 50 to 750 years as reported by DID Sarawak in 2001. This does not bode well for the Klias Forest Reserve which is surrounded by ongoing land development. A glimmer of hope is that the findings of this project suggest that hydraulic conductivities are spatially less than expected and that drainage impacts are limited and local in extent. However although the drainage impacts are currently quite local and subtle if widespread subsidence does occur around the reserve topographical and therefore hydrological gradient will increase and the threat of drainage impacts will increase accordingly. Such impacts will be most severe in the north and northwest of the forest reserve where the reserve boundary is some considerable distance from the hydrological boundary.Eastern and southern sections of the reserve are close to or partially enclose the hydrological unit boundary providing additional hope and focus for ongoing conservation efforts. The questions than remains as to how best manage what seemingly appears to be a conflict without resolve Since much land development has already taken place around the reserve it is now virtually impossible to ensure the long-term preservation of the hydrological unit only to reduce or delay insidious degradation of the forest reserve. Therefore strategies are now needed to provide guidance in decision-making regarding sustaining the hydrological integrity of the peat swamp forest within Klias Forest Reserve and to delay and slow the subsidence process. To do so necessarily means safeguarding the hydrology of peatlands outside of the reserve. While the proposed water management strategy deals with hydrological threats in the short term without major intervention the long term outlook for the hydrological and physical condition of the Klias Forest Reserve looks poor and management/maintaining the reserve will become increasingly challenging if not frustrating. The strategy suggested here is based upon current knowledge and literature and upon hydrological surveys and monitoring undertaken between October 2002 and June 2004. As such the recommendations are based on the best hydrological knowledge and interpretation of such data at this time. The focus of the study was to evaluate the impacts of current land development activities such as drains and log transport canals. It is proposed that the current ad hoc distribution of drains and canals is not the major threat to the forest reserve rather it is forest clearance outside of the reserve and and the development yet to come. Again this provides some hope for conservation choices as there may still be a chance to protect and maintain the hydrological integrity of the reserve. However unless major decisions are made in the near future to halt further alienation and development of land around the reserve this strategy may not be enough to ensure the survival of the Klias Forest Reserve. Remedial short-term effort to block drains and manage canals may contribute towards maintaining water levels locally which in itself is important but as to who should do so and who should provide the funding remains unclear. So again it is suggested that at this point in time the major thrust of the strategy is in terms of planning for the future rather than mitigating damage already done. The guidelines first introduce the main issues and thereafter describe suggested water management planning units. This is followed by the identification of activities which if undertaken cause an immediate threat to the hydrology.

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Abstract

The Klias peat deposit is characterised by a dome shape; being higher in the centre and north with the deposit sloping away to the edges and the south. The deposit is a contiguous hydrological unit. Hydrological change in one part of the unit will ultimately affect the rest of the unit. Occupying the central and topographic high of the dome is the Klias Forest Reserve which currently provides protection to the last remaining freshwater peat swamp forest of this type in Sabah. To either conserve or utilise a peat dome requires the management of each dome as a single hydrological unit as the water table in each deposit is contiguous. Contrasting uses within a single unit are likely to lead to conflicts wich although manageable in the sort term are unsustainable in the long term. The single greatest threat to any peat deposit undergoing development is subsidence. The initial rapid phase of subsidence takes place immediately after forest removal when the previously wet forest floor is opened up and oxidation takes place this phase reportedly lasts for a year or two. Thereafter subsidence continues albeit at a slower rate in proportion to lowered water levels a requirement of most agricultural development. Current knowledge and findings elsewhere in Malaysia state that even with improved water management subsidence cannot be halted. Ultimately the peat with disapear although this will depend upon the depth of the peat and will be on the time scale of 50 to 750 years as reported by DID Sarawak in 2001. This does not bode well for the Klias Forest Reserve which is surrounded by ongoing land development. A glimmer of hope is that the findings of this project suggest that hydraulic conductivities are spatially less than expected and that drainage impacts are limited and local in extent. However although the drainage impacts are currently quite local and subtle if widespread subsidence does occur around the reserve topographical and therefore hydrological gradient will increase and the threat of drainage impacts will increase accordingly. Such impacts will be most severe in the north and northwest of the forest reserve where the reserve boundary is some considerable distance from the hydrological boundary.Eastern and southern sections of the reserve are close to or partially enclose the hydrological unit boundary providing additional hope and focus for ongoing conservation efforts. The questions than remains as to how best manage what seemingly appears to be a conflict without resolve Since much land development has already taken place around the reserve it is now virtually impossible to ensure the long-term preservation of the hydrological unit only to reduce or delay insidious degradation of the forest reserve. Therefore strategies are now needed to provide guidance in decision-making regarding sustaining the hydrological integrity of the peat swamp forest within Klias Forest Reserve and to delay and slow the subsidence process. To do so necessarily means safeguarding the hydrology of peatlands outside of the reserve. While the proposed water management strategy deals with hydrological threats in the short term without major intervention the long term outlook for the hydrological and physical condition of the Klias Forest Reserve looks poor and management/maintaining the reserve will become increasingly challenging if not frustrating. The strategy suggested here is based upon current knowledge and literature and upon hydrological surveys and monitoring undertaken between October 2002 and June 2004. As such the recommendations are based on the best hydrological knowledge and interpretation of such data at this time. The focus of the study was to evaluate the impacts of current land development activities such as drains and log transport canals. It is proposed that the current ad hoc distribution of drains and canals is not the major threat to the forest reserve rather it is forest clearance outside of the reserve and and the development yet to come. Again this provides some hope for conservation choices as there may still be a chance to protect and maintain the hydrological integrity of the reserve. However unless major decisions are made in the near future to halt further alienation and development of land around the reserve this strategy may not be enough to ensure the survival of the Klias Forest Reserve. Remedial short-term effort to block drains and manage canals may contribute towards maintaining water levels locally which in itself is important but as to who should do so and who should provide the funding remains unclear. So again it is suggested that at this point in time the major thrust of the strategy is in terms of planning for the future rather than mitigating damage already done. The guidelines first introduce the main issues and thereafter describe suggested water management planning units. This is followed by the identification of activities which if undertaken cause an immediate threat to the hydrology.

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Item Type:	Proceedings Paper
Additional Information:	10 ills.
AGROVOC Term:	PEATLANDS
AGROVOC Term:	FOREST RESERVES
AGROVOC Term:	DRAINAGE
AGROVOC Term:	WETLANDS
AGROVOC Term:	WATER MANAGEMENT
AGROVOC Term:	PEAT
AGROVOC Term:	MALAYSIA
Geographical Term:	MALAYSIA
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:28
URI:	http://webagris.upm.edu.my/id/eprint/16776

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