Factors such as flow and sediment characteristics affecting the spur dike’s local depth of erosion have yielded considerable research results, but there is little discussion of the geometry of the spur dike’s local scour holes. This study focuses on the spatial characteristics of the geometry of local scour holes in straight-wall spur dikes. The discussion shows that the spur dike arrangement clearly changes the plane geometry of the scour hole. The maximum scour depth has a power function relationship with the area of the scour hole and the scour hole-volume. Moreover, the ratio of the product of the maximum scour depth and the plane area of the scour hole to the scour hole-volume is a fixed constant. The average slope of upstream of the scour hole and along the axis direction of the spur dike is slightly larger than the angle of repose of the sediment, the slope distribution of the scour holes profiles presents an inverted “U” type, and its profile morphology and slope distribution have geometric similarity. This distribution also reflected that, the interaction between the downward flow and the horseshoe vortex inside the scour hole leads to the formation of a cusp.

In the context of global climate change, the frequency of watershed flooding events resulting from extreme rainfall has significantly increased. Especially at river or lake confluences, the presence of backwater effects greatly amplifies the flood risk. To investigate the influence of backwater effects on the hydraulic characteristics of rivers and lakes, this study focuses on the Dongping Lake in China. An enhanced two-dimensional hydrodynamic model was employed to simulate and analyze three different degrees of backwater effects. The results indicate that, compared to the working conditions without the backwater effect, the highest lake water level increased by 1.0 m and 0.1 m under severe and moderate backwater effect conditions, respectively. The total outflow flood volume decreased by 30.1% and 2.3%, respectively. The demolition time for the Jinshan Dam needs to be advanced by 12.5 h and 10.0 h, respectively, and the inundation area in the western region expanded by 2.73% and 0.32%. Additionally, the average inundation depth increased by 0.93 m and 0.08 m, respectively. These results provide valuable data support for the safe operation of Dongping Lake, the formulation of flood defense strategies, and, likewise, offer valuable insights into the risk management of flood events in other rivers and lakes with backwater effects.

Dam breach can trigger severe flood disasters, threatening life and property safety, and having long-term impacts on the environment, society, and the economy. Dam breach floods also contaminate water bodies, degrading water quality and its sustainability. This study analyzes the characteristics and trends of dam breach research using research findings included in the CNKI (China National Knowledge Infrastructure, Beijing, China) database and the Web of Science (WoS) core database. Bibliometric methods, including word frequency analysis, co-citation analysis, and clustering analysis, were applied to the retrieved data. Using the CiteSpace (v6.3.R2) visualization tool, the study conducted statistical analyses and generated maps for publication trends, research institutions, and research hotspots. The findings indicate the following. (1) From 2000 to 2023, the number of research outcomes has been continuously growing both domestically and internationally with significantly more foreign-language publications than Chinese ones. (2) Chinese research institutions, notably the Chinese Academy of Sciences and the Nanjing Hydraulic Research Institute, have substantial international influence. (3) In terms of research hotspots, Chinese studies focus on the failure mechanisms of earth-rock dams, while foreign studies emphasize dam breach flood flows. (4) Establishing numerical models has emerged as a common trend in both Chinese and foreign research. These insights help identify deficiencies in current methods and technologies, allowing for the proposal of more scientific strategies for dam safety assessment. Based on these conclusions, some insights are proposed with the aim of reducing the risk of dam breaches, ensuring sustainable water resource management and utilization, promoting environmental protection, and fostering harmonious socio-economic development.