Kazakhstan journal for oil & gas industryKazakhstan journal for oil & gas industry2707-42262957-806XKMG Engineering10901610.54859/kjogi109016Conceptual Assessment of Potential Ural River Channel Changes Associated with Caspian Sea Level Decline Through Computer-Based ModelingKhassanovBakhytzhan K.b.khassanov@kbv.kzhttps://orcid.org/0009-0007-2006-9127StepanchukArtem M.a.stepanchuk@kbv.kzhttps://orcid.org/0009-0000-6022-7141RomanAnelkazakh.7979@mail.ruhttps://orcid.org/0000-0003-3489-9475Kashagan B.V.KMG "Kashagan B.V."841206202613102026Copyright © , Khassanov B.K., Stepanchuk A.M., Roman A.<h1 data-section-id="1q7k9pi" data-start="0" data-end="10">Abstract</h1> <h2 data-section-id="1cc82z" data-start="12" data-end="25">Background</h2> <p data-start="27" data-end="663">The decline in the Caspian Sea level has been observed over recent years and is considered one of the key long-term risks for all operators in the Northern Caspian region. A decrease in the sea level may alter flow directions, water depths, and the configuration of river channels discharging into the Caspian Sea, including the Ural River. Changes in the position of the main Ural River channel could significantly affect the offshore infrastructure and logistics of the Kashagan Field, as the Ural River and adjacent water areas are used for cargo delivery, equipment transportation, dredging operations, and environmental monitoring.</p> <h2 data-section-id="151jjl6" data-start="665" data-end="677">Aim</h2> <p data-start="679" data-end="960">To investigate the potential behavior of the Ural River channel, the Ural-Caspian Canal, and delta distributaries under projected Caspian Sea level decline using computer-based modeling, with the aim of assessing risks and logistical implications for the Kashagan Field operations.</p> <h2 data-section-id="13xhl4q" data-start="962" data-end="986">Materials and Methods</h2> <p data-start="988" data-end="1624">The historical evolution of the Ural River delta over the past 200 years was examined. Flood events and channel processes were simulated for various Caspian Sea level decline scenarios. Flow directions, inundation areas, and the potential formation of new distributary channels were analyzed. Required hydraulic parameters were derived, and thematic maps were produced. The computer model was developed using cartographic, topographic, bathymetric, morphometric, hydraulic engineering, hydrological, geological, and scenario-based datasets. A two-dimensional hydrodynamic model was constructed using the MIKE 21 FM software package.</p> <h2 data-section-id="22sytk" data-start="1626" data-end="1640">Results</h2> <p data-start="1642" data-end="2598">During the period 1985–2024, most left-bank distributaries of the Ural River delta exhibited a tendency toward channel narrowing and configuration changes as a result of the declining Caspian Sea level. Modeling results indicate that the majority of river discharge continues to be directed toward the Ural Trough. Under lower sea-level conditions, the formation of new distributaries is possible, predominantly oriented toward the southeast and south-southeast. These newly formed channels are local in nature and are not navigable. Even under the most unfavorable scenarios, floodwaters do not reach the boundaries of the Kashagan Field or its marine access channel. The existing seabed topography, as well as the presence of islands and shoals in the Northern Caspian, remains the primary controlling factor governing flow directions. No significant evidence was identified to suggest a redirection of river discharge toward Kashagan project facilities.</p> <h2 data-section-id="8dtpi" data-start="2600" data-end="2613">Conclusion</h2> <p data-start="2615" data-end="3034" data-is-last-node="" data-is-only-node="">Computer-based modeling demonstrated that the projected decline in the Caspian Sea level will not result in a redirection of the Ural River channel or its delta distributaries toward the Kashagan Field. The findings indicate the absence of hydrological and geomorphological risks associated with the natural migration of the Ural River channel toward the Kashagan development area within the forecast period up to 2075.</p>Ural River, Caspian Sea level decline, modeling, Kashagan field, flooding, flood events, Ural Trough, prediction of channel deformations.Жайық өзені, Каспий теңізі деңгейінің төмендеуі, модельдеу, Қашаған кен орны, су басу, су тасқындары, Жайық ойысы, арналық деформацияларды болжау.река Урал, снижение уровня Каспийского моря, моделирование, месторождение Кашаган, затопление, паводки, Уральская бороздина, прогнозирование русловых деформаций1.Samoylov, I.V. River Mouths. Moscow: Geografgiz, 1952.2.Yumina, N.M., Magritsky, D.V. Forecasting Water Levels in the Lower Reaches of the Ural River // Eurasian Union of Scientists (EUS), No. 6 (63), 2019, pp. 4–9.3.Sergaliyev, N.Kh., Akhmedenov, K.M. 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