Development of a conceptual reservoir-type model for salinity simulation along the tidal river
In: Journal of Hydrology. Elsevier: Tokyo; Oxford; New York; Lausanne; Shannon; Amsterdam. ISSN 0022-1694; e-ISSN 1879-2707, more
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| Author keywords |
Seawater intrusion;Conceptual model;High salinity;mike11;Scheldt estuary;intrusion;risk |
| Authors | | Top |
- Zhu, B.
- Willems, P., more
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| Abstract |
Increasing saltwater intrusion in estuaries driven by climate change and human activities necessitates efficient predictive tools, yet high-resolution models remain computationally prohibitive for large-scale applications. This study presents a conceptual reservoir-type model (CM), which is a simplification of the full hydrodynamic 1D MIKE11 framework, designed to balance accuracy and computational efficiency. The CM comprises two modules: (1) a hydrodynamic module resolving discharge (Q) and water level (WL) via sequential reservoir calculations, and (2) an advection-dispersion module simulating salinity (S) dynamics using the finite difference method. Validated for the Scheldt Estuary against MIKE11 simulations, the CM achieves Nash-Sutcliffe Efficiency (NSE) > 0.9 for WL, > 0.8 for Q, and > 0.85 for S, effectively capturing spatial gradients (e.g., downstream-to-upstream decline), tidal variability, and abrupt tributary impacts (e.g., Rupel River). Despite the coarser spatial resolution ( 6,000 m vs. MIKE11's 300 m for S node spacing), the CM demonstrates the capacity to accurately simulate S dynamics, with slight overestimations, particularly excelling in simulating high 95th percentile salinities. Moreover, the CM reliably estimates S at non-aligned spatial nodes with simple interpolation, as demonstrated through validation against field data. After scenario testing, its high computational efficiency and spatial flexibility (enabling rapid sub-reach adaptation without grid reconfiguration) support scalable and robust applications like zoning management for saltwater monitoring under climate change. |
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