Study on Characteristics of Riverbank Collapse in Typical Section of the Lower Yellow River
The frequent bank collapse in the local sections of the lower reaches of the Yellow River seriously endangers the safety of embank-ments and floodplains.This study conducted field observations in the typical reaches of the lower Yellow River,aiming to describe the proces-ses and characteristics associated with riverbank collapse.Complementary to these observations,cross-sectional survey data were employed to elucidate the influences of soil composition and water-sediment conditions on riverbank collapse in the lower Yellow River.The results show that riverbank collapse causes lateral widening of the main channel in the lower Yellow River,with the magnitude of failure masses exhibiting notable temporal and spatial variability.In comparison to the pre-flood period,the bankfull width of the main channel at the reach scale in the key reach is increased by 57.03 and 7.83 m after the 2006 and 2018 floods respectively.In addition,the maximum lateral erosion distance on one side of the representative cross-section reaches to an alarming value of 207.20 m.In the lower Yellow River,the predisposition to river-bank failure during the flood season is attributed to the low degree of compaction and poor impact resistance of the topsoil,compounded with an inverse relationship between the shear strength and increasing water content.The water-sediment condition characterized by'high flow-low sediment'is prone to riverbank failure,while the hyper-concentrated flow mitigates riverbank erosion by facilitating sediment siltation in the near-shore riverbed.This study recommends further long-term monitoring of typical riverbanks and advocates the adoption of ecological river-bank revetments based on the consideration of flood safety.
riverbank collapsein-situ observationssoil compositionwater-sediment conditionslower Yellow River
万方数据
维普
