An evaluation of the extrapolatory method of soil mapping

Similar field procedures for mapping soils have been used in Alberta for the last 15 years or more. The need to investigate alternative procedures for mapping soils is apparent in view of the increasing demand for soil and land information, and the decreasing availability of financial and human resources to support conventional soil surveys.

Several alternative methods for conducting soil inventory have been proposed and tested. A review of the literature on methods of soil mapping and techniques for evaluating soil map utility and accuracy was conducted by the Alberta Research Council in 1992. The review identified ten methods with potential for increasing the speed of soil mapping in Alberta. This study evaluates one of the mapping methods (extrapolation) in terms of map accuracy and compares this method to SIL3 1:50 000 soil mapping. Two other methods, top-down and landscape, were examined in an earlier report (Nikiforuk, Fawcett and MacMillan, 1993).