A case study was conducted for the Thailand Khao Lak coast using a forward numerical model to understand uncertainties associated with interpreting tsunami deposits and relating them to their tsunami sources. We examined possible effects of the characteristics of tsunami source, multiple waves, sediment supply and local land usages. Numerical results showed that tsunami-deposit extent and thickness could be indicative of the slip value in the source earthquake near the surveyed coastal locations, provided that the sediment supply is unlimited and all the deposits are well preserved. Deposit thickness was found to be largely controlled by the local topography and could be easily modified by backwash flows or subsequent tsunami flows. Between deposit extent and deposit thickness, using deposit extent to interpret the characteristics of a tsunami source is preferable. The changing of land usages between two tsunami events could be another important factor that can significantly alter deposit thickness. There is a need to develop inversion models based on tsunami heights and/or run-up data for studying paleotsunamis. 相似文献
Blockage in water-dominated flow pipelines due to hydrate reformation has been suggested as a potential safety issue during the hydrate production. In this work, flow velocity-dependent hydrate formation features are investigated in a fluid circulation system with a total length of 39 m. A 9-m section pipe is transparent consisted of two complete rectangular loops. By means of pressurization with gas-saturated water, the system can gradually reach the equilibrium conditions. The result shows tha... 相似文献
Mega-earthquakes and extreme climate events accompanied by intrinsic fragile geology lead to numerous landslides along mountain highways in Taiwan, causing enormous life and economic losses. In this study, a system for rapid slope disaster information integration and assessment is proposed with the aim of providing information on landslide occurrence, failure mechanisms, and subsequent landslide-affected areas to the highway authority rapidly. The functionality of the proposed system is deployed into three units: (1) geohazard rapid report (GeoPORT I), (2) multidisciplinary geological survey report (GeoPORT II), and (3) site-specific landslide simulation report (GeoPORT III). After landslide occurrence, the seismology-based monitoring network rapidly provides the initial slope disaster information, including preliminary location, event magnitude, earthquake activity, and source dynamics, within an hour. Within 3 days of the landslide, a multidisciplinary geological survey is conducted to collect high-precision topographical, geological, and remote-sensing data to determine the possible failure mechanism. After integrating the aforementioned information, a full-scale three-dimensional landslide simulation based on the discrete element method is performed within 10 days to reveal the failure process and to identify the areas potentially affected by subsequent disasters through scenario modeling. Overall, the proposed system can promptly provide comprehensive and objective information to relevant authorities after the event occurrence for hazard assessment. The proposed system was validated using a landslide event in the Central Cross-Island Highway of Taiwan.
Natural Hazards - From 2015 to 2017, construction for the Dalixi Eco-Industrial Park in Dalixi Village, Xingshan County in the Three Gorges Reservoir area, reactivated a series of ancient... 相似文献
Geotechnical and Geological Engineering - Underground water-sealed storage cavern is an important way for petroleum strategic reserve in China, which owns lots of outstanding advantages, such as... 相似文献
Measuring fluxes of greenhouse gases (GHGs) is fundamental to estimating their impact on global warming. We examined diurnal variations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) vertical fluxes in a tidal marsh ecosystem. Measurements were recorded on neap and spring tide days in April and September 2010 in the Shanyutan wetland of the Min River estuary, southeast China. Here, we define a positive flux as directing into the atmosphere. CH4 fluxes on the diurnal scale were positive throughout, and CH4 emissions into the atmosphere on neap tide days were higher than on spring tide days. CH4 releases from the marsh ecosystem on neap tide days were higher in the daytime; however, on spring tide days, daily variations of CH4 emissions were more complex. The marsh ecosystem plays a twofold role in both releasing and assimilating CO2 and N2O gases on the diurnal scale. Average CO2 fluxes were positive on the daily scale both on neap and spring days and were greater on the neap tide days than on spring tide days. Diurnal variations of N2O fluxes fluctuated more. Over the diurnal period, soil temperature markedly controlled variations of CH4 emissions compared to other soil factors, such as salinity and redox potential. Tidal water height was a key factor influencing GHGs fluxes at the water–air interface. Compared with N2O, the diurnal course of CO2 and CH4 fluxes in the marsh ecosystem appeared to be directly controlled by marsh plants. These results have implications for sampling and scaling strategies for estimating GHGs fluxes in tidal marsh ecosystems. 相似文献
