Methodology for Comparing Soil Maps of Different Dates with the Aim to Reveal and Describe Changes in the Soil Cover (by the Example of Soil Salinization Monitoring)

A methodology for comparing soil map of different dates in order to reveal changes in the soil cover is discussed. The analysis of a set of the maps of soil salinization on one of the farms in the Golodnaya Steppe region of Uzbekistan is used as an example. It is shown that traditional methods of comparing two maps developed in different years (normally, with an interval of five years and more) are low informative for the assessment of soil salinization dynamics. The suggested methodology assumes simultaneous analysis of several maps in order to reveal the trends in soil salinization. However, even in this case, the obtained results do not adequately characterize the dynamics of soil salinization on irrigated fields. It is argued that the direction of soil salinization-desalinization processes is an improper characteristic in this case. In order to understand the dynamics of soil salinization, the maps showing the dynamism of soil salinity and the maximum changes in the degree of salinity can be applied. A series of the compared maps make it possible to describe the changes in the soil cover related to salinization-desalinization processes. The high dynamism of these processes against the background of a virtually stable pool of soluble salts in the 1-m-deep soil layer is shown for the considered farm.