A Study of the Processes of Desertification at the Modern Delta of the Ili River with the Application of Remote Sensing Data

Abstract

The water regime is the main factor contributing to the formation of landscapes in the river deltas of arid zones, any fluctuations in which lead to a change in the integral hydromorphic landscape. After the construction of the Kapshagai reservoir, the anthropogenic load on the ecosystem of the Ili River delta increased, as a result of which degradation processes, such as drying out and salinization, intensified. In the short term, this phenomenon may lead to the desertification of about 1 million ha of land in the modern river delta. In this regard, the main goal of this study is to look at the processes of desertification in the modern delta of the Ili River, using remote sensing data, which allows for quick identification of the long-term dynamics of degradation processes. For this, the authors used satellite data from Landsat 1-5 MSSS and Landsat 8OLI satellites for 1979 and 2019 and soil analysis data obtained through the ground (field) surveys. Using regression analysis of space and soil data, predictors for interpreting space images were identified and maps of landscape drying and soil salinization were compiled, reflecting the changes that have occurred over the past 40 years. As a result, it was found that in 2019, compared to 1979, the area of landscapes covered with vegetation had decreased by 12% and there was a transformation of hydromorphic landscapes into salt marshes and solonetzes. Over the past 40 years, the volume of non-saline soils has decreased by 41.3% and the volume of saline soils has increased to varying degrees. That is, at present, on the territory of the modern delta, a difficult land improvement situation has developed associated with the cessation of spring and summer floods due to the intensive water use at the Chinese and Kazakh sides.

Mapping of Cornfield Soil Salinity in Arid and Semi-Arid Regions

“…Large scales mapping spatial, temporal, and depth variability of soil salinity is one of the fundamental steps in salinity management at irrigation in arid and semi-arid areas [Li et al, 2020]. Usually, soil salinity monitoring is often carried out with intensive sampling from observation points and an appropriate interpolation method to estimate salinity values for unsampled locations [Laiskhanov et al, 2021].…”

“…In world practice, the use of the space method for studying soil salinity is currently one of the most important new areas of soil science. And it is fundamentally different from its analogue -the ground-based method of studying soil salinity by its method of conducting (Remote Sensing), it allows effective use of the cost and time spent on field research, as well as increasing the reliability and completeness of the information obtained by optimizing the surveying period [Laiskhanov et al, 2021]. A review of recent scientific publications shows that the problem of soil salinity over large areas has not yet been solved [Masoud and Koike, 2006;Ajay, 2021].…”

“…The main feature of remote sensing is that it allows to assess the salinity of irrigated soils over large areas using satellite imagery, which is impractical for terrestrial surveys [Abbas et al, 2013]. However, knowledge of characterizing and monitoring soil primary and secondary salinity, as well as the correlation between of the soil quality and index values of satellite imagery involves the collection of soil samples for chemical analyses and electrical conductivity (EC) under field work [Laiskhanov et al, 2021]. Most researchers in recent years have been actively using Sentinel 2A and 2B satellite data for such studies, which can provide higher resolution up to 10 m [Segarra et al, 2020;Taghadosi et al, 2019;Laiskhanov et al, 2022].…”

Exploring the complexities of sand dune transformation: the role of anthropogenic degradation and climatic conditions

“…Consequently, the primary objective of our research is to examine seasonal geomorphological and hydrothermal processes within a single sand dune for a comprehensive understanding of their formation and the development of aeolian processes. Numerous studies of sand dune systems have been conducted globally, with recent research shifting toward modeling and remote sensing methods for sand dune development (Tsoar, 1983;Yizhaq et al, 2009;Diniega et al, 2010;Do et al, 2018;Auyelbek et al, 2021;Laiskhanov et al, 2021;Amanbayeva et al, 2022;Smyth et al, 2022;Zheng et al, 2022;Kalybekova et al, 2023). Nonetheless, this emerging focus does not render fieldwork obsolete, as accurate empirical field studies remain essential for a clear understanding of sand dune geomorphology.…”

A Study of the Effects of Soil Salinity on the Growth and Development of Maize (Zea Mays L.) by using Sentinel-2 Imagery

“…Of the 272.5 hectares, 66% are occupied by desert and semi-desert lands (Zhumabaev, 2015). The volume of saline and saline soils amounted to 116 million hectares (42.5% of the total land area), indicating that salinization, including secondary salinization, is the primary degradation process leading to desertification (Otarov et al, 2008;Laiskhanov et al, 2021). Especially the proportion of weedy soils in the soil structure of the river basins such as the Syr Darya, Ili (Otarov et al, 2008;Laiskhanov et al, 2016Laiskhanov et al, , 2021 is increasing year by year.…”