|
Soil-agricultural maps at a scale of 1:5 000 were prepared in the 1960’s in the analogue form (colour and black and white) for the area of the entire country. They were developed based on the existing classification maps as well as field and laboratory studies preceded by the interpretation of aerial photographs. They constitute a valuable collection of information on the soil conditions, agricultural usefulness of land, and indirectly on the usefulness of the land for other, non-agricultural functions. They constitute a source of information used in taking planistic decisions. Contours with an area of more than 0.5 ha were marked on the maps. Small or narrow elements providing significant information on the agricultural production space were included. The accuracy of the contours distinguished is estimated for approx. 10-50 m. The uncertainty of the location of the boundaries results from the accuracy of marking of soil-agricultural contours, and lack of consideration of the continuality of changes in the soil cover both in the geographical space and in the space of attributes describing it. Currently, based on the order of the Council of Ministers of 3 October 2011 on types of thematic and special cartographic documents [Journal of Laws No. 222, item 1328], thematic maps, including agricultural maps, are to become thematic digital documents considered in the spatial information infrastructure. The objective of the paper is to present methods of cartographic presentation of digital soilagricultural maps with consideration of data uncertainty. Majority of terms describing soil, related to soil typology or assessment of soil quality and agricultural usefulness, is relatively little precise. This is related to the specificity of the geographical phenomenon of soil. Majority of soil processes form continuous (fuzzy) classes. For a soil-agricultural map, they are constituted by fuzzy contours of belonging to a given agricultural usefulness complex. Lack of certainty, resulting from imprecise markings of terms applied, is modelled with the application of the theory of fuzzy sets and fuzzy logic. The spatial distribution of values of belonging of a soil phenomenon to an individual fuzzy class can be presented on the map by means of the conventional cartographic method. This generates a number of maps equal to the number of distinguished classes. This does not automatically lead to the determination of spatially continuous classes in the form of one presentation. There are methods of development of a result map presenting the distribution of a given phenomenon with consideration of the fuzziness of boundaries between the distinguished classes. They can be divided into three categories: defuzzification, methods based on the Confusion index, and graphic methods. The article provides a review of selected methods of cartographic presentation with their adaptation for the purposes of a soil-agricultural map. The colour scales were developed in the CIECAM (CAM - Colour Appearance Model) perceptual colour space independent from the devices reproducing colours, and from the observation conditions. Moreover, their relation to the CIE Lab colour space for specified, typical observation conditions was determined, as well as RGB values for the standard monitor adopted.
|