Large-scale Soil Maps Improved by Digital Soil Mapping and GIS-based Soil Status Assessment

Abstract

A key issue of the applicability of both traditional soil maps and soil information systems (SSISs) is their accuracy. Essentially, the main practical aim of soil surveys/mapping and spatial soil information is prediction. A traditional tool of this information extension is the classical (crisp) soil map (using soil mapping units), which generally constitute the geometric basis of SSISs, too. Numerous novel methods have been developed for producing more accurate soil maps, however traditional crisp soil maps are still extensively applied, as they offer the most easily interpretable results for the majority of users. On the other hand, accuracy of this kind of soil maps can be increased in several ways: with the refinement of soil contours; with the subdivision of mapping units taking into consideration smaller, within patch inhomogeneities; and with the refinement of attribute information (more recent data, more precise measurement, up-to-date methodology, more appropriate classification etc.). The GIS adaptation of soil information originating from the 1:25,000 scale practical soil mapping of Hungary is under construction. Compilation of the Kreybig Digital Soil Information System (KDSIS) involves both its integration within appropriate spatial data infrastructure and updating with efficient field correlation, which make an inherent refinement and upgrading of the system possible. The first attempts for the field-based updating of KDSIS have been done, using field GIS technology. Processes of desktop and field reambulation of the detailed, complex, national spatial soil information system are presented in this paper.