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The bed degradation of a compound channel induced by a base level fall can significantly impact the flood conveyance capability and stability of riverine structures. This study found that severe compound channel degradation is due to the coupled effects of flood discharge and base level fall. Laboratory experiments examined the impact of base level fall on the grain size distribution at the bed surface, flow discharge in the main channel and floodplains, and longitudinal profile of the bed elevation. Two riverbed degradation patterns of a compound channel after base level fall were clarified. Relative to the original bed slope, degradation pattern (I) had a higher bed slope, but degradation pattern (II) had a lower one. A calculation method was proposed to determine the critical conditions for identifying these two riverbed degradation types. Both experimental and published data confirmed that the proposed method is valid for identifying these two compound channel degradation patterns. [ABSTRACT FROM AUTHOR]

Rock weirs are low-head river restoration structures. The present study comprised two sets of flume tests (i.e. fixed bed and moveable sand bed tests) to investigate the rock dislodgement process, which is a primary cause of the failure of rock weirs. The impacts of approach flow intensity, submergence, void ratio and scour of bed sediment on rock weir dislodgement, and the responses of sediment bed scour at rock weirs to the rock weir dislodgement, are analysed and discussed. Three limits are defined to classify the amount of the rock weir dislodgement: (1) limit I indicates the incipient dislodgement of rock from downstream weir toe; (2) limit II indicates that a few rocks are dislodged from downstream weir face and weir crest; (3) limit III indicates that large numbers of rocks are dislodged from downstream weir face and weir crest, which leads to weir failure. A predictor of each limit is proposed for rock weir design. [ABSTRACT FROM AUTHOR]

In recent years, RS and GIS technologies have played an increasingly important role in various aspects of rainfall induced landslide research. In order to systematically understand their application situation, this paper extensively used various visualization analysis technologies for in-depth analysis of 1,161 documents collected by the WOS data platform in the past 27 years by combining quantitative and qualitative methods. Then, this article focuses on sub domain analysis from four aspects: landslide detection and monitoring, prediction models, sensitivity mapping, and risk assessment. The study found that the number of literature in this field has steadily increased and is expected to continue to rise. This literature review has attracted widespread attention from the academic community, but it is challenging to meet research needs. Frequent and effective cooperation between countries, institutions, and authors is very beneficial for promoting progress in this field. The future development direction is a new intelligent hybrid model that integrates multiple research methods. This study can provide researchers in this field with the core research force, hot topic evolution, and future development trends of future rainfall-induced landslides and contribute to landslide prevention and control decision-making and achieving the United Nations'sustainable development goals. [ABSTRACT FROM AUTHOR]