題 目：Early warning systems for natural hazards-- the fundamentals
主講人：Prof. Tad Murty （Department of Civil Engineering, University of Ottawa, Canada）
時 間：2012年12月7日 下午3:00-5:00
地 點：主樓六層會議室
主講人簡介：
Prof. Tad Murty, PH.D (Meteorology& Oceanography), University of Chicago, USA
Formerly
1. Senior Research Scientist, Canadian Oceanographic Service.
2. Director of Australian National Tidal Facility.
3. Professor of Earth Sciences, Flinders University, Adelaide, Australia.
4. Director, Sea level and Climate monitoring project, Government of Australia.
At present
1. Editor, Natural Hazards, published by Springer in the Netherlands.
2. Edited the Storm Surge Manual, for the World Meteorological Organization, Geneva
3. Vice President, International Tsunami Society, Honolulu
4. Adjunct Professor, Department of Civil Engineering, University of Ottawa, Canada
內容簡介：
Natural hazards can be broadly classified into three groups, namely permanent, evanescent and episodic. Under permanent hazards, one can include tides, wind waves coastal erosion, sedimentation and climate change. Evanescent hazards are those for which there is no clear beginning or clear ending. Examples include droughts and sea level rise. No warning systems are in place for these two types, rather, either routine predictions or continuous monitoring of various parameters is the norm. Episodic hazards have a clear beginning and a clear ending. Large scale hazards of this type include earthquakes, tsunamis, hurricanes, stormsurges, winter storms, river floods, volcanic eruptions. Medium scale hazards include landslides, snow avalanches, flash floods, meso-scale weather systems such as squall lines, Rissaga and Kallakkadal. Small scale hazards include Karst, sink holes, rip currents. For episodic hazards early warning systems are in place. There are three types of wave motion in the oceans, ocean wave spectrum is clearly separate for short period and long period waves. Wind waves and swell are short period waves, while tides, storm surges and tsunamis belong to the class of long gravity waves. Clustering is the most common phenomena in geophysical processes and the Hurst phenomenon, Joseph, Noah and Eden effects in Hydrology attest to the clustering. The role of aliasing in geophysical data records is explored. Other topics discussed include: precision versus accuracy, fuzzy mathematics, lateral thinking and probability versus determinism in the prediction of natural hazards. Finally the difficulty problem of the computation of coastal inundation from tsunamis and storm surges is discussed. The Eulerian techniques do not work properly for these multiple-connected regions and Lagrangian methods such as SPH (Smoothed Particle Hydrodynamics) are better suited.
