Limans irrigation regime in Yakutia in a changing climate

The distinctive features of estuary irrigation, the current state and characteristics of estuary irrigation systems in the agricultural zones of Yakutia are given. On the example of typical estuary irrigation systems located in the Lena–Aldan and Leno–Vilyui interfluves, the regime of estuary irrigation in a changing climate is considered. It has been established that in the areas of estuary irrigation of Yakutia over the past 50 years, there has been an increase in the average annual temperature of atmospheric air from 1.5 to 3 ℃, which led to an increase in the sum of temperatures of the growing season over the past 8 years by 160 ℃ in the Lena–Aldan and Lena–Vilyui interfluves and date of commencement of irrigation of estuary meadows for earlier dates up to 5 days. An analysis of the amount of precipitation during the growing season shows a decrease in the amount of precipitation over the past 8 years from 90 mm to 80 mm in the Khorobutskaya FIS, located in the Lena–Aldan interfluve, and an increase from 96 mm to 120 mm on average in the Orosun–Negodyakh FIS, located in Leno - Vilyui interfluve. The yield for 2014-2021 in the Orosun-Negodyakh FIS increased comparatively by an average of 2 centners per hectare, while in the Khorobutskaya FIS, on the contrary, it decreased by an average of 3 centners per hectare. Studies on reclamation systems show the closest dependence of productivity on the sum of atmospheric temperatures and precipitation in the Orosun-Negodyakhskaya FIS, in the Khorobutskaya FIS on the total precipitation. In general, the conducted studies show the impact of climate change on the irrigation regime of estuary irrigation systems located in various agricultural zones of Yakutia and the need for their revision.