Abstract Dike failure is a disaster that brings extensive damage. Studying the characteristics of breach flow is of great practical significance for breach closure and reducing flood damage. However, experimental research on the surface morphology and velocity field of breach flow during the process of dike-break remains relatively limited. In this study, a large-scale experimental model of instantaneous dike-break induced flow under various flow conditions was conducted. The simultaneous measurement of water surface morphology and surface velocity fields near the breach was achieved using three-dimensional surface particle tracking velocimetry measurement technology. Based on the morphological evolution of the breach water surface, the dike-break process was divided into three stages: initial stable water tongue formation, gradual submergence, and eventual disappearance. The dimensionless water surface profile elevation along the breach centerline during the first stage exhibited similar characteristics under varying experimental conditions. The surface velocity also exhibited relatively stable distribution patterns along the breach centerline during this stage. The dimensionless water-level difference between the main channel side and floodplain side decreased with increasing initial water depth. However, the water-level difference between the downstream and upstream sides within the main channel increased with higher initial river velocities. The surface velocity of breach flow exhibited an initial increase to a peak followed by a decline, with the peak value showing a positive correlation with the initial channel depth. These findings revealed the evolution of breach flow surface morphology and velocity field, enhancing understanding of hydrodynamic processes of dike failure.
Groundwater resources face increasing stress due to climate change and rapid urban growth in semi-arid regions. The current study used an integrated approach involving the Analytic Hierarchy Process (AHP), Geographic Information System (GIS), and Remote Sensing (RS) to delineate groundwater potential zones in Tangshan City. Seven important thematic layers were derived from the geospatial database. These layers were assigned weights based on expert knowledge and normalized them using AHP techniques to generate GWPZ map. The results indicate that around 35.6
Understanding how groundwater systems respond to climate change and ecological water replenishment is vital for sustainable water resource management. In this study, a physically based coupled surface water–groundwater model (SWAT-MODFLOW) was developed for the upstream region of the Chaobai River Basin in northern China. Future rainfall data from three Coupled Model Intercomparison Project Phase 6 (CMIP6) scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) were downscaled and bias-corrected into the coupled model. The coupled SWAT-MODFLOW model accurately captures the phase and amplitude of streamflow at a representative hydrological station and seasonal groundwater fluctuations at all observation wells. Simulations under future climate scenarios revealed projected rainfall increases of 15
Evapotranspiration, as an important component of the water cycle on the Qinghai-Tibet Plateau (QTP), has long been a hot topic and challenge in research due to the difficulty in accurately quantifying it. Complementary models have gained widespread use for their ability to simulate evapotranspiration using only conventional meteorological data. While the key parameter α _e has been demonstrated to vary with temporal scales and regions, the factors influencing this variability remain unclear, and dynamic parameterization methods are still lacking. This study conducted an analysis of the parameters and influencing factors of the complementary model (C2018 model) based on 14 eddy flux stations on the QTP, and fitted the relationships between parameters and environmental factors. The results showed that the calibration parameter values ( α _e ) of the 14 eddy flux stations ranged from 1.07 to 1.54, exhibiting a strong correlation with the multi-year monthly average temperature and net radiation (correlation coefficients of -0.71and − 0.47, respectively). Using stepwise regression to fit the relationship between α _e and environmental variables, and embedding these parameters into the C2018 model, approximately 86 α _e proposed in this study provides scientific support for plateau evapotranspiration estimation, hydrological mechanism analysis, and water resource management.
The seismic analysis of an open water-sediment-foundation-dam (WSFD) system can be decomposed into a free-field problem for an auxiliary system and an interaction problem for a bounded WSFD system. Both of them involve complex wave coupling problems across multiple different media. This study develops a partitioned method and integrates a 2D-3D finite element procedure, based on a generalized saturated porous medium (GSPM) model and a novel localized Lagrange multipliers (LLM) method. The GSPM model fundamentally eliminates multi-solver coupling through a unified representation of heterogeneous media. The novel LLM method enables simultaneous interaction of multiple different media, transcending the inherent limitations in classical fluid-solid interface treatments. In implementation, a more realistic input for the bounded system is provided by computing the free-field for the auxiliary system using the 2D procedure, reducing numerical errors caused by multi-transmitting boundary. The accuracy of the partitioned method is examined through numerical simulations of an idealized dam–2013;reservoir–2013;foundation system, with results compared against those obtained from the direct method. Finally, the effects of sediment and nonlinearity on dam are investigated by augmenting a plastic-damage constitutive module.
