Coastal regions are dynamic areas that often lie at the junction of different natural hazards. Extreme events such as storm surges and high precipitation are significant sources of concern for flood management. As climatic changes and sea-level rise put further pressure on these vulnerable systems, there is a need for a better understanding of the implications of compounding hazards. Recent computational advances in hydraulic modelling offer new opportunities to support decision-making and adaptation. Our research makes use of recently released features in the HEC-RAS version 5.0 software to develop an integrated 1D–2D hydrodynamic model. Using extreme value analysis with the Peaks-Over-Threshold method to define extreme scenarios, the model was applied to the eastern coast of the UK. The sensitivity of the protected wetland known as the Broads to a combination of fluvial, tidal and coastal sources of flooding was assessed, accounting for different rates of twenty-first century sea-level rise up to the year 2100. The 1D–2D approach led to a more detailed representation of inundation in coastal urban areas, while allowing for interactions with more fluvially dominated inland areas to be captured. While flooding was primarily driven by increased sea levels, combined events exacerbated flooded area by 5–40% and average depth by 10–32%, affecting different locations depending on the scenario. The results emphasise the importance of catchment-scale strategies that account for potentially interacting sources of flooding.
The Dahongliutan granitic pluton consists of two-mica granites and is located in the eastern part of the Western Kunlun Orogen, northwestern Tibetan Plateau. Zircon separates from the pluton yield a SIMS U–Pb age of 217.5 ± 2.8 Ma. Rocks from the pluton contain relatively high and uniform SiO2 (72.32–73.48 wt%) and total alkalis (Na2O + K2O = 8.07–8.67 wt%) and are peraluminous and high-K calc-alkaline to shoshonitic in composition. The Dahongliutan granites are relatively depleted in the high-field-strength elements and the heavy rare earth elements (HREEs) and have relatively high Rb, and low Ba and Sr concentrations. They contain low total rare earth element (REE) concentrations. The light REEs are strongly enriched relative to the HREEs, with (La/Yb)N values of 28.56–37.01. The εNd(t) values range from ?10.6 to ?8.8, and (87Sr/86Sr)i = 0.7142–0.7210. Zircons from the pluton yield εHf(t) values of ?13.8 to ?1.6, and δ18O = 10.5–11.6‰. Petrographic and geochemical features of the pluton indicate that the granites are S-type and were derived from parting melting of a mixture of metasedimentary and minor metaigneous sources in the middle–lower crust. Magmatic differentiation was dominated by the fractional crystallization of plagioclase, K-feldspar, muscovite, biotite, and accessory monazite, allanite, and Fe–Ti oxides. Regional granitoids were emplaced in the Early-to-Middle Triassic. Other younger granitoids, with ages of 240–200 Ma, are mostly I-type in character and were likely derived from multiple types of source rock, suggesting the source was heterogeneous Triassic crust. Such a scenario is consistent with their formation in a post-collisional setting. Our new data, combined with other geological evidence, suggest that the collision between the Tianshuihai and southern Kunlun terranes occurred between ca. 250 and 240 Ma, resulting in the closure of the Palaeo-Tethys. Post-collisional tectono-magmatic events may have occurred between 240 and 200 Ma. 相似文献