Assessment of the Status of Irrigated Lands in the Nukus District of the Republic of Karakalpakstan in the Geoinformation System

The results are given of a study of the status of irrigated lands in the Nukus district of the Republic of Karakalpakstan by geographic information systems (GIS). The urgency of this work is related to serious environmental problems caused by land degradation due to climate change and deterioration of water supply in the region. The composition of the soil cover and changes in the quality of irrigated lands for the period from 2012 to 2019 have been calculated and analyzed. The results obtained enable us to reveal the dynamics of degradation processes and may be used as a basis for developing measures to improve ecological conditions and soil fertility. This work proves the need for an integrated approach in agricultural management and in the use of irrigated land, which is especially important for the sustainable development of the region. The most noticeable structural changes in the use of soil resources are related to the expansion of cultivated areas of alluvial-meadow desert saline (solonchak) (old-tugai) soils by 7% of their total area and to the reduction of the area of cultivated meadow-marsh soils from 45 to 30%. Despite these changes, the parameter of the quality of irrigated lands remains at the same level. The quality structure of irrigated lands is predominated by medium-quality plots: the quality scores attributed to the lands are 40–50 for about half of the croplands, 30–40 for a third of the area, and higher than 50 for slightly more than a fifth of lands (the most productive ones). The composition of the soil cover of irrigated lands has also remained practically unchanged. The analysis shows that the basis of irrigated agriculture in the region consists of alluvial-meadow desert saline (solonchak) (old-tugai) soils, which occupy 60% of arable land with a similar rate of their development in the region.