Discussion
The above analysis shows that using the least-cost path model to harvest productive sites was an achievable method in terms of forest road layout in the study area FMU L1J. The method had both advantages and disadvantages in terms of the data acquisition, data quality and assumptions, etc.
1. Benefits
Simplicity and better decision making
The whole process was easy to use based on each step outlined in the project. In addition, the tools used were built in the ArcGIS tool box. Most professional forest managers and forest engineers would have access to the ArcGIS software due to its popularity and wide spread-use. Further control points can be included, if some factors, such as soil properties, are deemed to be potentially significant along the route. For example, control points could serve as connecting points between the mill and the cutblocks. The least-cost path would be derived from segments, the division of which are determined by the control points. It also provides decision support about locations, in fields such as real estate selection, planning, conservation and route or corridor selection.
The whole process was easy to use based on each step outlined in the project. In addition, the tools used were built in the ArcGIS tool box. Most professional forest managers and forest engineers would have access to the ArcGIS software due to its popularity and wide spread-use. Further control points can be included, if some factors, such as soil properties, are deemed to be potentially significant along the route. For example, control points could serve as connecting points between the mill and the cutblocks. The least-cost path would be derived from segments, the division of which are determined by the control points. It also provides decision support about locations, in fields such as real estate selection, planning, conservation and route or corridor selection.
2. Limitations
Data AcquisitionOne limitation in the process of determining the productive harvest sites process, was that no DEM data was initially available. Therefore, there was no slope data contributing to the harvest operability analysis. After obtaining DEM data, a general evaluation was made on the final productive harvest sites, labelled as GStands. In this case, however, slope did not present a major problem, as the terrain was, in general, very flat (mostly less than 30%).
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Comparison of analysis Tools like Cost Distance, Path Distance tool “calculates, for each cell, the least accumulative cost distance to the nearest source”, but it also accounted for surface distance and horizontal and vertical cost, which added more complexity to the analysis (ESRI, 2012). Unfortunately, the project did not focus on the comparison of these tools. If more time was available, the effects of the different tools applied would have been presented.
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Determination of weighted valueReclassification and Weighted Overlay were important key steps, as these steps were responsible for assigning different influence power of landscape type on the least-cost path. Water bodies, Aboriginal Reserve, Caribou ranges etc. were not equally important. Thus, the corresponding weighted value should be carefully assigned to reflect the significance of different input variables.
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