Characteristics of Computerized Soil Maps

Abstract

AbstractIn computer‐generated interpretive soil maps, a detailed soil map is generalized by selecting the dominant soil by estimation within a grid or unit cell. The soil mapping unit from the detailed soil map is retained for its higher predictive value.Interpretive maps are generated by computer translation of the dominant soil in each unit cell to a rating and then printing the result on unlined paper as a graphic display. A study was made of the agreement between detailed soil maps and those generalized using various cell sizes. On a soil survey map with a medium amount of cartographic detail, the average agreement was 70.5, 64.4, and 48.4% for unit cell sizes of 8.64 ha (21.33 acres), 16.20 ha (40 acres), and 64.80 ha (160 acres). On soil maps with low, medium, and high amounts of cartographic detail, the average agreement was 71.6, 64.4, and 41.3%, respectively, for a standard unit cell size of 16.20 ha (40 acres). The t test was used to test the agreement between the acreage of soil mapping units obtained from the MIADS program versus the acreage measured by dot counting. The test showed no differences in sample means of the two methods for samples tested.