The ecosystem of the Urals: how to save a transboundary river from degradation
Russian scientists have proposed to rethink the principles of the distribution of water resources in the transboundary basin of the Ural River (Zhaiyk), which flows through the territory of Russia and Kazakhstan. In their opinion, the current approaches based on fixed volumes of water supply do not take into account the consequences of climate change and the deterioration of river ecosystems. A study conducted by specialists of the Russian Research Institute for Integrated Use and Protection of Water Resources (RosNIIVH) Oksana Nikitina and Alexey Kosolapov, emphasizes the need to move to more flexible, ecosystem-oriented solutions.
The current state of the Ural basin is of concern to environmentalists. In recent decades, the water regime of the river has changed: runoff has increased in winter and decreased in summer and autumn. Biological indicators also indicate degradation. In the middle reaches of the Urals, the species diversity of phytoplankton decreased by 35 species, and the number of major commercial fish, such as carp, bream, pike and pike perch, decreased. The most critical situation has developed with the sturgeon population – about 90% of spawning grounds in the lower reaches of the river have been lost due to siltation and overgrowth.
A key element of the new approach is the introduction of the concept of “ecological runoff”. This is a certain amount of water that must be guaranteed to remain in the river to maintain the health of aquatic and coastal ecosystems, preserve biodiversity and the ability of the river to self-purify. This volume is proposed to be reserved as a priority and not included in the distribution among water users. This approach is already used in international practice, for example, in Mexico, and is also incorporated into the new Water Code of Kazakhstan.
The researchers carried out calculations of ecological runoff for a section of the river near the Russian-Kazakh border. Depending on the methodology and the water content of the year, the volume required to maintain the ecosystem is estimated to range from 59% to 83% of the total annual runoff. This means that only the remaining part of water resources can be used for economic needs, which requires more rigorous planning of water use.
The existing mechanism of distribution of the waters of the Urals is regulated by the protocol between Russia and Kazakhstan of 1996. However, the analysis showed that the volumes contained in it in some periods, especially in low-water years, are lower than the estimated needs of the ecosystem. This indicates the need to revise existing agreements taking into account modern scientific data and changed natural conditions. According to scientists, the inclusion of the provision on ecological runoff in interstate documents will be an important step towards balanced management of water resources.
The proposed approach involves building a clear hierarchy: first of all – ensuring the needs of the river ecosystem as the basis of its sustainability, and secondly – meeting socio-economic needs, including drinking, municipal and industrial water supply. Although ecological runoff is not the only measure, it creates a fundamental basis for the restoration of the river. Comprehensive efforts should also include improving water quality, restoring valuable natural habitats and combating poaching.
The results of the study are preliminary in nature, but they can serve as a basis for the work of intergovernmental commissions and expert groups to clarify the mechanisms of flow distribution in the Ural basin. The developed approaches can also be applied to the management of water resources of other large transboundary rivers, where issues of balance between economic development and nature conservation are acute.
Original (in Russian): Экосистема Урала: как спасти трансграничную реку от деградации
