Особенности многолетней изменчивости увлажнения ландшафтов Акмолинской области Республики Казахстан по данным спутниковой съемки

Abstract

The aim of the study is to identify features of long-term variability of the moisture state of the vegetation and soil cover of the steppe zone of northern Kazakhstan. To identify the peculiarities of the variability of the state of natural humidification of landscapes (vegetation and soil) during the growing season of the long-term time interval (from 1976 to 2020), data from satellite images of the territory of the Ishim River Valley and the city of Atbasar, located in the Akmola region of the Republic of Kazakhstan, were analyzed. Based on the data of long-term meteorological observations and on the results of decryption of satellite images, the variability of the NDMI humidity index (normalized difference index of moisture in vegetation and soils) for 44 years for the period 1976‑2020 was characterized. The NDMI humidity index has increased values and intensity of color in the images at the air temperature below the norm (or near the norm) and the amount of precipitation above the norm for this territory. The NDMI humidity index has lower values at air temperatures above normal (or near normal) and the sum of precipitation below normal for a given territory. The low degree of moisture in vegetation and soil at the time of satellite survey is preceded by the arid previous 30-day period (also vice versa). A color scale of gradation of the NDMI humidity index values for use in assessing the humidity of the landscapes of Akmola region and adjacent territories of the northern part of Kazakhstan is proposed.