Author(s): Ibrahim Halil Demirel; Giovanni De Cesare

Linked Author(s): Ibrahim Halil Demirel

Keywords: Flow regime alteration; Hydropower regulation; Ecohydrology; Hydropeaking; Eco-deficit

Abstract: This study investigates flow regime alteration from hydropower regulation in two contrasting hydroclimatic systems: the Rhône River (Switzerland) and the Çoruh River (Türkiye). Change-point, trend, and ecological deficit analyses using daily flow data (2000–2024) reveal that regulation primarily alters temporal rather than volumetric components of flow. Increased rise–fall rates in the Rhône indicate intensified hydropeaking, whereas regulation in the Çoruh basin, including upper-basin cascade developments, is associated with smoother short -term variability patterns. Despite stable baseflows, both rivers show seasonal eco-phase shifts and artificial timing patterns, reflecting anthropogenic control over natural regimes. The findings demonstrate that regulation produces “artificial seasonality” and emphasize the need t o integrate ecohydrological indicators such as Richards–Baker Flashiness Index, Baseflow Index, and Eco-Deficit into hydropower management and water policy frameworks to ensure ecological resilience.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.157

Year: 2026