Probability distributions of wave phases in association with distributions of surface elevations are studied with wave records. Wave records of different nature are used for comparison. These are surface fluctuations ...Probability distributions of wave phases in association with distributions of surface elevations are studied with wave records. Wave records of different nature are used for comparison. These are surface fluctuations acquired during wind wave flume experiments, representing wave generation under strong wind; and wave records measured in the northern part of Taiwan for waves in natural environments. Three probability models, the unifrom distribution, the beta distribution, and a model from Tayfun and Lo (1989) are adopted to study the possible distributions of wave phases. It is found that when surface elevations become skewed, wave phases deviate from the usually assumed uniform distribution and a better model would be the beta distribution.展开更多
Recent advances in hydraulic modeling create improved methodology to accurately predict the extent of floodplain map in order to assist policy makers to develop flood hazard mitigation measures and timely inform the l...Recent advances in hydraulic modeling create improved methodology to accurately predict the extent of floodplain map in order to assist policy makers to develop flood hazard mitigation measures and timely inform the local communities with the flood risk alerts.However,accurate prediction of the inundation map also depends on the spatial resolution of the topographic data.In this study,we developed a novel high-resolution modeling framework for Nashwaak River watershed,New Brunswick,Canada to capture significant flooding along the banks of the river for the two historic flood events and accurately map the floodplains for both the gauged and ungauged areas of the watershed.The model is based on HEC-RAS(US Army Corps of Engineers Hydrologic Engineering Center River Analysis System)hydraulic model and the topographic data were generated from high-resolution LiDAR data of~0.5 m.The model runs were driven by observed flow conditions applied at the boundary and the framework is based on different spatial resolution to determine the effect of spatial resolution on the predicted inundation.We validated the model simulated water surface elevation with the observed data and the model reproduces reasonably good skill score.Results from the numerical simulation suggest that apart from the strength of the stream velocity,design of the modeling framework plays an important role in determining the inundation depth as well as the maximum flooding extent.展开更多
文摘Probability distributions of wave phases in association with distributions of surface elevations are studied with wave records. Wave records of different nature are used for comparison. These are surface fluctuations acquired during wind wave flume experiments, representing wave generation under strong wind; and wave records measured in the northern part of Taiwan for waves in natural environments. Three probability models, the unifrom distribution, the beta distribution, and a model from Tayfun and Lo (1989) are adopted to study the possible distributions of wave phases. It is found that when surface elevations become skewed, wave phases deviate from the usually assumed uniform distribution and a better model would be the beta distribution.
基金funded by the ETFNB Environmental Trust Fund of New Brunswick(grant No.170099).
文摘Recent advances in hydraulic modeling create improved methodology to accurately predict the extent of floodplain map in order to assist policy makers to develop flood hazard mitigation measures and timely inform the local communities with the flood risk alerts.However,accurate prediction of the inundation map also depends on the spatial resolution of the topographic data.In this study,we developed a novel high-resolution modeling framework for Nashwaak River watershed,New Brunswick,Canada to capture significant flooding along the banks of the river for the two historic flood events and accurately map the floodplains for both the gauged and ungauged areas of the watershed.The model is based on HEC-RAS(US Army Corps of Engineers Hydrologic Engineering Center River Analysis System)hydraulic model and the topographic data were generated from high-resolution LiDAR data of~0.5 m.The model runs were driven by observed flow conditions applied at the boundary and the framework is based on different spatial resolution to determine the effect of spatial resolution on the predicted inundation.We validated the model simulated water surface elevation with the observed data and the model reproduces reasonably good skill score.Results from the numerical simulation suggest that apart from the strength of the stream velocity,design of the modeling framework plays an important role in determining the inundation depth as well as the maximum flooding extent.
