Abstract: Bedload sediment transport in unsteady flows is a fundamental research topic in river dynamics. Over the last few decades, a number of researchers at home and abroad have conducted a series of exploratory studies, achieved insightful understanding, and made great contributions to this subject. This paper reviews the recent advances in the knowledge of bedload sediment transport under unsteady flows, in terms of (i) hysteresis, (ii) hysteretic loops of hydraulic and sediment parameters, (iii) bedload sediment transport rate, and (iv) total bedload yield. Based on an analysis of previous works and findings, we highlight related issues with relevant studies, and make suggestions for addressing these issues.

Key words: unsteady flow, bedload, hysteresis, sediment transport rate, bedload yield