Water

Lakes and rivers pose as another variable that must be left out of MCE analysis. A water image was created using 2 shapefiles from the DMTI datasets. In ArcMap, UNION was used to create one shapefile combining the two. The WATER_UNION shapefile was then rasterized, transformed into ASCII and imported into IDRISI.

According to the B.C. Forestry Practices Code (FPC), buffers must be placed around riparian zones in order to ensure their protection from human activities. The Community Watershed Guidebook (1996) determines that streams of various classes and stream widths require different buffer zones. The table below shows required reserve (buffer) zones for various stream sizes. The management zone was not considered in this case as very limited, if any, forest cover will be removed. Due to stream class/width uncertainty in the water dataset, an average of 25 m was considered sufficient for my purposes.

Due to the complicated nature of watercourses, buffering in IDRISI was far more efficient than buffering in ArcMap. Buffering in ArcMap would have produced a more spatially accurate map whereas in IDRISI, the program would not let me insert "25 m" as a viable buffering option. The cell size of the water image was at 992 m, in which case I used a 1 pixel buffer (992 m). Using ArcMap to buffer the lakes and rivers would have taken numerous hours (I ran the buffer in ArcMap for 2.5 hours and was uncertain it was co-operating until I tried it again and realized that it was due to the detail of the water shapefile.) The macro model is as follows: