The aim of the study is to determine and substantiate the most typical form of local moisture contours and to obtain dependences describing the boundary and inner isopleths of local drip irrigation contours. In analytical study, the analysis of moisture contours parameters, formed under different soil and technical-technological conditions during drip irrigation was carried out. Analyzing the linear parameters of moisture contours (depth and width), they were transformed into relative values, which made it possible to compare profiles and assess similarities of various contours of drip humidification and the in-circuit isopleths with different moisture levels. As a result of analysis of parameters (forms) of moisture contours formed under different soil and technical-technological conditions during drip irrigation, it was found out that dependence providing a contour description of the most typical shape and position of in-circuit isopleths in relative coordinates at preset values of contour depth and radius and taking into account the constants characterizing soil and technological conditions of moisture contour formation can be taken as a base line. As a result of research, an experimental dependence describing the shape of the moisture contour formed in soil space during drip irrigation allowing to determine boundaries with an acceptable accuracy (12 % for practical use and subsequently the areas and volumes of moistening zones in relative coordinates during drip irrigation.
Key words: drip irrigation, irrigation norm, moisture contour, pre-irrigation moisture, isopleth, contour profile.
