SPECIFICATIONS FOR SOIL SURVEY INTENSITY (SURVEY ORDER) IN CANADA
This study was an evaluation of soil survey methods, particularly soil survey intensity (survey order), based on information from 53 recent surveys in Canada. The data were gathered by questionnaire and indicate that revisions to the specifications outlined by the Expert Committee on Soil Survey are required.(1) An index calculated from the density (number of inspections per unit area) and distribution (percent of delineations with at least one inspection) of soil inspections allocates a survey unambiguously to one survey intensity level (SIL).(2) For each SIL, ranging from 1 (very detailed) to 5 (exploratory), the proportion of delineations with at least one inspection is reduced, and a smaller proportion of the total length of soil boundaries is checked in the field. A closer spacing of traverses at each SIL is recommended.Other information shows that SIL 5 surveys are more appropriately published at a scale of 1:250 000 than the usual 1:100 000; a smaller proportion of time is spent in the field in surveys of lower intensity; soil surveyors concentrate more on describing areas than verifying boundaries; and rates of progress at a given intensity level vary among different physiographic regions, with slowest progress in the Canadian Shield. Key words: Soil survey, intensity, order, index, Canada