The geophysical, hydrological, and ecological consequences of the Russia‐Ukraine war for the major rivers and water infrastructure in Ukraine are addressed here, focused on the dams and reservoirs of the Dnipro (Dnieper) River and major tributaries, up to and including the destruction of the Kakhovka Dam in June 2023, using remote sensing systems, on‐the‐ground reports, and official sources. The rivers have long played a role as physical barriers during conflicts, but in the current war, water and built water systems have also been targeted for attacks and used as both offensive and defensive weapons. Among the consequences of the conflict have been both direct and indirect effects on civilian populations, agriculture, military operations, water supplies and quality, and natural ecosystems. An historical review shows that such attacks have occurred in the past, but the extent and severity of the current violence appear unprecedented, raising important questions of international law and how international legal and scientific communities should respond.

The usage of remote sensing data for tracking or monitoring war conflicts is a reality nowadays. The Russian invasion in Ukraine seriously impacted on the environment of the attacked country in all areas: air, soil, water, flora and fauna. The war has created a massive increase in air pollution in some regions of Ukraine, and might have effect in neighbouring countries. The Russian attack has caused many fires at places such as oil depots, industrial complexes, equipment and ammunition stockpiles, the forests, and residential areas. In addition to this, many bridges, hydraulic and other structures located over and near the water bodies were destroyed. These events were analysed in this paper by using publicly available remote sensing data: NOAA-2, Suomi NPP, Aqua and Terra satellites, Sentinel and Landsat satellites, as well as from other sources open to public. We assume that the use of remote sensing data is an excellent tool to monitor effects of military conflicts on environment. The conducted research with proposed method can serve as a good scientific practice that should be implemented for monitoring of the harm to nature caused by wars.

Based on the results of regular monitoring and remote sensing data the patterns of water temperature of the reservoirs cascade on the Dnipro River were identified. A characteristic feature of the thermal regime of the Dnipro Cascade has been the water temperature increase over the past decades. In the period 1977–2020 the water temperature in summer increased by 0.74 °C decade⁻¹, and during May–October by 0.65 °C decade⁻¹. An important factor influencing the thermal regime of the reservoirs is the influence of those ones, located upstream. Water from them is discharged from the lower layer, where the processes of heating and cooling are very slow. This has a significant influence on the water temperature of downstream reservoirs, especially on their upper part. The water temperature in this part during spring and summer seasons is lower compared to natural conditions. In autumn it is higher. The temperature of water also depends on the latitude: it rises in the reservoirs located both downstream and to the south. Another important factor influencing the water temperature is the wind, which can change the temperature in the surface layer by 5–6 °С. Water temperature also depends on the intensity of algae bloom – it is higher in the spots of a large bloom.

The results of the studies devoted to the consequences of the Kakhovka dam destruction on June 6, 2023 in the course of the Russia-Ukraine war are presented. After the accident, the Kakhovske reservoir, which was the largest by volume on the Dnipro River, practically disappeared. It has turned into the network of river branches and lakes that do not compare with the former reservoir. Currently, the conditions on the territory of the former reservoir have approached those observed in natural conditions. To some extent, they depend on the water discharge of the Dnipro River, more exactly, on the water discharge of the Dnipro HPP located upstream. In the conditions of large water runoff, the large part of the former Kakhovske reservoir is covered with water. An unusual natural phenomenon of the area of the former reservoir is very rapid overgrowth, primarily by willow. A year after the accident, its height in places which is rich in organic sediments exceeded 4 meters. At the same time, the size of the trees on the bottom covered by sands is much smaller. Today, a large area of the former reservoir looks like a dense forest.