نوع مقاله : پژوهشی
نویسندگان
بخش تحقیقات منابع طبیعی مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان گلستان، سازمان تحقیقات، آموزش و ترویج کشاورزی
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Using multi‑temporal satellite imagery—QuickBird (2005), SuperView (2019), Pléiades (2019)—together with UAV data (2024), this research analyzes the morphodynamic evolution and classification of meandering forms of the Atrak River within the Chat‑Gonbad reach in Golestan Province. The methodological approach is based on visual interpretation and geometric analysis of 21 identified meander reaches and the delineation of four major geomorphological units. Quantitative findings reveal a clear trend toward greater geometric complexity. The number of straight, low‑sinuosity channels (sinuosity < 1.5) observed in 2005 (two cases) completely disappeared by 2024, while high‑sinuosity channels (> 1.5) increased from nine in 2005 to ten in 2024, indicating a continuous intensification of lateral channel instability. Hydrological and annual runoff analyses show that the 2018–2019 water year was an extreme and unprecedented event, recording roughly 390 million m³ of annual runoff. The associated 15‑day flood had a peak discharge of 108 m³/s and a total flood volume of 24 million m³, acting as a hydrological threshold that coincided with an abrupt morphological adjustment in the Atrak River. During the post‑flood period (2019–2024), internal depositional forms expanded and migrated, while stable vegetation gradually developed on these newly formed sediments—signifying the river’s morphodynamic reorganization and adaptation toward more complex meandering patterns. Overall, these results demonstrate the Atrak River’s rapid and sensitive response to extreme hydrological events and the intensification of its transition from simple to complex morphodynamic configurations within the study reach.
کلیدواژهها [English]
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