This article presents a comprehensive assessment of degradation risk in the arid territories of the Ili district, Almaty region, based on Sentinel-2 satellite indices, MODIS NPP and ERA5-Land hydroclimatic variables. The aim of the study was to identify the spatial distribution of degradation risk and to determine how the condition of the soil-vegetation cover is related to moisture and temperature factors during 2020–2025. The integrated risk map was produced using four normalized components: NDVI, BSI, surface albedo and VCI. MODIS NPP for 2020–2024, precipitation, air temperature, wind speed, snow water equivalent and 0–28 cm soil moisture were used as additional explanatory variables. High and very high integrated risk classes occupy 7318.9 km², or 88.91% of the analysed area, whereas strict hotspot zones cover 24.7 km² (0.30%). The strongest significant relationships were found between NPP and May–September precipitation (r = 0.954; p = 0.0118) and between NPP and 0–28 cm soil moisture (r = 0.962; p = 0.0087). NDVI and VCI were positively associated with snow water equivalent, while NDVI showed a negative relationship with May–September temperature. The Mann–Whitney test confirmed that hotspot areas have lower NPP and soil moisture than non-hotspot areas. The results indicate that degradation risk is formed by the combined effects of reduced vegetation condition, increased soil exposure, higher surface reflectance and moisture deficit.

Kazakhstan’s Ili River delta nourishes a unique wetland ecosystem in arid Central Asia. The delta is dominated by common reed [Phragmites australis (Cav.) Trin. ex Steud.], an ecologically and economically significant species that is sensitive to water levels. We used machine learning methods, including the Random Forest algorithm, to classify common reed-containing wetland vegetation and water surfaces in the delta based on satellite data from 2000 to 2023. The remote sensing results were integrated with field-based geobotanical studies conducted between 2017 and 2019. These studies, which facilitated identification of three classes of vegetation: meadow, marsh and aquatic, also revealed a good correspondence between predicted and measured common reed biomass per unit area. The long-term dynamics of four wetland communities with a common reed content of ≥25% were analyzed with respect to significant interannual variability in the flow of the Ili River. The highest water inflows and water surface areas in the delta were recorded in 2002, 2010 and 2016, and in each case, a statistically significant expansion of common reed was observed one year later. Common reed areas subsequently declined—rapidly or after a lag of several years. Temporal expansion and contraction of these areas following pulses of water differed substantially from that of overall wetland vegetation as measured previously. The identified patterns have important scientific and practical significance for assessing the stability of the surrounding wetlands, preservation of the delta environment, and sustainable use of common reed.

Forest ecosystems are one of the most important components of the Earth's biosphere due to their global ecological and socio-economic importance. In hydromorphic landscapes of arid regions of Central Asia with its sharply continental climate, these ecosystems are represented by unique in their biodiversity and environment-forming role coastal tugay forests in river floodplains, flooded lowlands and islands. Among desert, semi-desert and steppe ecosystems, tugay forests are ecosystems with the highest aboveground biomass and biodiversity. Due to the growing reduction of runoff of most rivers in Central Asia due to increased water consumption by agrarian and industrial production and negative climatic changes, the area of tugay forest ecosystems has catastrophically decreased. Ecological restoration of degraded tugay forests is a key factor in combating desertification in arid regions. Taking into account the fact that tugay forest ecosystems are currently represented only by scattered areas exclusively in West and Central Asia, their conservation is of global importance. The results of a comprehensive study using remote sensing and GIS-technologies, field work to assess the successional dynamics of tugay ecosystems in the middle reaches of the Ili River in connection with hydrological and climatic factors are presented in the article. Key words: tugay ecosystems, remote sensing methods, vegetation degradation, climate change, river flow regulation, ecosystem conservation.