The impact of temporary occupation and hostilities on the water conditions of the North Crimean and Kakhovka Main Canals

The aim was to analyse the dynamics of water resources of the North Crimean and Kakhovka canals from 2013 to 2024 using remote sensing methods. The study utilised satellite imagery from Landsat 8 OLI/TIRS L2 (2013-2015) and Sentinel-2 L1C (2016-2024). The deep learning model “Water Body Extraction (SAR) – USA” based on Sentinel-1 C band SAR GRD VH data was applied. The normalised difference water index was used to detect water surfaces. Manual digitisation of the canals was performed based on time composites of satellite images over the study period. The analysis revealed significant changes in the water conditions of the canals due to natural and anthropogenic factors. Following the annexation of Crimea in 2014, the cessation of water supply from the Dnipro River led to the drying of canals on the peninsula, negatively affecting agriculture and ecosystems through soil salinisation and degradation. In 2015, the length of canals with water in Crimea decreased to 161.65 km. Alternative sources, such as artesian wells, partially compensated for the lack of water but led to groundwater depletion. From 2016 to 2021, the length of canals with water in Crimea continued to decrease, reaching 150.17 km in 2020. In 2022, after the destruction of dams in the Kherson Region, uncontrolled filling of canals with water occurred. Due to infrastructure degradation, a significant portion of water infiltrated into the ground, causing water losses. In 2023, the destruction of the Kakhovka Hydroelectric Power Plant dam led to the shallowing of the Kakhovka Reservoir and changes in the hydrological regime of the canals, reducing the length of canals with water in the Kherson Region to 448.41 km, and in 2024 to 298.98 km. These events caused erosion and lowering of groundwater levels, negatively affecting agriculture due to reduced irrigated areas