Hydro-morphology, channel change and sediment transport dynamics of major Albanian Rivers

This dissertation offers a comprehensive exploration into the hydromorphological transformations of major Albanian rivers, situated within the unique ecosystem of the Western Balkans. Covering the Mat, Ishmi, Erzen, Shkumbin, Seman, and Vjosa rivers, the research spans critical facets of river dynamics, contributing vital insights for effective river basin management in line with the European Union Water Framework Directive and Floods Directive. Examining nearly 80% of the Albanian river network, with catchment areas exceeding 650 km², the study reveals the present dominance of single-thread (22%) and sinuous (17%) river morphologies. Notably, a distinct trend towards channel narrowing emerges, with historical analyses showcasing substantial shifts, including transformations from braided to wandering (39%) and braided to sinuous (10%). Meandering reaches experience a 21% alteration, with 20% transitioning into abandoned reaches. Over five decades, approximately 53 km of river channels shift into abandoned status, emphasizing the impact of channelization, land cover changes, and natural river cut-offs. This country-wide analysis establishes a foundational understanding for river basin management, flood prevention, and restoration, crucial as Albania moves towards EU membership. Focusing specifically on the Erzen River, a major watercourse passing near Tirana and Durres, the research delves into meticulous analyses of channel adjustments, incision, and narrowing. Utilizing remote sensing, historical image analyses, DEM, and field surveys, the study reveals rapid changes in channel morphology, including up to 75% channel narrowing and significant riverbed incision. Sediment mining emerges as a primary driver, with 22 mining sites detected between 1995-2015. These observed channel modifications contribute to coastal erosion and potential downstream freshwater shortages, emphasizing the urgent need for effective sediment transport management. Accurate data and predictive calculations play a crucial role in achieving sustainable river management. Further exploring sediment transport dynamics, the study analyses historical hydrology data from 1949 to 1992 for the Erzen River. A calibrated sediment transport capacity predictor offers insights into the impact of channel changes on sediment transport rates. Comparison with the nearby Shkumbin River reveals important baselines to understand the intricate relationship between human activities, sediment transport, and coastal erosion. The research addresses a critical question: to what extent have modifications in channel morphology affected sediment transport capacity in selected Albanian rivers? The findings underscore the pivotal role of predictive calculations in developing basin management plans aligned with EU directives. In essence, these integrated findings provide a nuanced understanding of hydromorphological changes in major Albanian rivers, offering comprehensive insights into the evolving river dynamics. The research serves as a foundational resource for policymakers, scientists, and stakeholders, advocating for sustainable river basin management practices to preserve the ecological significance of the Western Balkans' unique river systems for future generations.