Derivation of Land Qualities to Assess Environmental Problems from Soil Surveys

Abstract A digitized soil map with scale 1:50 000 of a sandy area of 2000 ha in the Netherlands was used to derive interpretive maps showing gradations of three land qualities of importance in assessing environmental problems. An interactive graphics computer system (IGS) was used. The land qualities calculated from soil properties of the unsaturated zone were: (i) travel times of water, (ii) cation exchange capacity (CEC), and (iii) phosphate sorption capacity (PSC). Transfer functions were defined, relating soil characteristics (texture, organic matter content, and oxalate‐extractable Al and Fe, integrated across horizons designation) to the land qualities. Water‐table levels were defined in terms of the mean highest (MHW) and the mean lowest (MLW) levels. Land qualities were expressed in terms of classes that spanned the range of observed spatial variability. The IGS system can produce interpretive maps from the soil map almost instantly, given selected inputs such as specified water‐table levels.