A Method of Calculating Surface Area Using Geographical Information System (GIS

This research was carried out in a section of Kheirood-Kenar educational and research forest station
with the mean slope of 76 percent. A method of estimating the surface area using the slope is
introduced which has vast applications in all areas of natural resource management. Statistical analyses
of the collected data showed a significant relation between surface and plan metric areas with the
slope, but there is not significant relation between the two areas Mon-significant difference between
difference of surface and plan metric areas is a confirmation of joint effect of plan metric area and
slope on surface area. For determining the surface area, the mean slope of the area can be used in the
equation given by the authors (equation 1), but it is preferred to use the slope of each cell.
Furthermore, two presented graphs (5, 6) can be used to find one factor given anyone of the slope or
the difference between surface area and plan metric area in percent. The for areas up to 55 percent
slope difference between surface area and plan metric area is less than 10 percent of plan metric area.