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The Roles of GIS/RS in the National Movement of Forest Land Rehabilitation Development of a GIS-based monitoring and evaluation system – the next step
Due to time and data constraint, criteria to determine spatial distribution and location of Namfor were based upon three parameters: (i) land cover, (ii) forest function, and (iii) land sensitivity. Land covers describe phenomena of earth surface such as forest, shrub, bush, agricultural land, settlement etc. Forest functions divide forest lands into three functions: conservation, protection and production, whereas land sensitivity determines sensitivity of land in watershed areas based upon erosion hazard rate and sedimentation rate as described in the Minister of Forestry Decree No. 284/Kpts-II/1999. Watershed area is an ecological unit of forest land depending upon physical and chemical characteristics of the area, and drainage system such as direction of rivers and streams in the area. Criteria of location for Namfor were then determined as follows:
Priority I : areas with high land sensitivity, and unproductive. Priority I is directed to rehabilitation with 100% tree planting.
Priority II : areas with moderate land sensitivity, and less productive. Priority II is directed to enrichment planting or weeding/thinning.
Priority III : other areas outside priority I and II that need for conservation and environmental quality enhancement.
2. Collecting and processing data
Data concerning three parameters were collected in the process of identification to determine priority location of forest land rehabilitation.
(i) Land cover.
Interpretation of Landsat imageries was the main sources of land covers. Landsat imageries were classified into 23 classes; from these classes three groups were then generated to meet the criteria.
- Group I is unproductive, non forested areas consisting of bush/shrub, dry agricultural land mixed up with bush/shrub, swamp areas, and bare land.
- Group II is less productive, logged over areas consisting of secondary forests of - dry land, swampy areas and mangrove.
- Group III is other land covers consisting of savanna, agricultural land, rice field, mining, and settlement.
(ii) Forest functions.
MoFRI categorized forest lands into three functions: (i) conservation – to preserve specific characteristics and biodiversity, (ii) protection – to protect land from erosion, preserve drainage and hydrological patterns, and (iii) production – to produce wood/non-wood products. Identification was carried out in all forest functions. Digital data of forest functions were created from provincial forest land use plan maps.
(iii) Land sensitivity.
As previously described, land sensitivity was determined based upon sensitivity of land in watershed areas in terms of erosion rate, and sedimentation rate as described in the Minister of Forestry Decree No. 284/Kpts-II/1999. The decree categorized areas of watershed management into four priorities: priority I – super priority, priority II – high priority, priority III – moderate priority, and priority IV – less priority. Digital data was derived watershed mapsmfrom the DGLRR.
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