Study On Rapid Assessment Of Earthquake Losses In North-South Seismic Belt

The earthquake is one of the most devastating natural disasters which threaten human lives. Destructive earthquakes may cause enormous harms and great damages to national economic construction,people’s life and property security. To evaluate earthquake loss timely and accurately after the earthquake is of great significance to emergency response establishment,the government’s earthquake relief decision and the reconstruction work.Therefore, to get the disaster information timely and accurately, to evaluate economic loss and casualties caused by earthquakes and to provide a basis for the relevant departments’emergency rescue are the urgent needs of the decision makers and the public.North-South seismic belt is large in scale and consist of a series of complex faults. Nearly half of M>8earthquakes has occurred in this area according to past records and earthquake frequency is much higher than other mainland area. Therefore, fast loss assessment model and technique applied to this area has practical significance for emergency relief and minimizing loss farthest.This paper selected North-South seismic belt as study area.In order to meet the needs of evaluating disaster situation and building loss,we developed "an idea of fast realizing the seismic intensity map" and "fast evaluating building loss based on kilometer grid".Taking Wenchuan Ms8.0earthquake,Yingjiang Ms5.8earthquake and Lushan Ms7.0earthquake for example,we obtained reliable results.In order to carry out the work above, lots of relevant papers had been read:relevant technique of earthquake intensity evaluation, common fast evaluating earthquake loss methods and their application status.Vulnerability classification list method,macroscopic vulnerability method and methods based on GIS and RS to evaluate earthquake loss fastly are the most used methods at the present stage.On the basis of the present earthquake intensity evaluation method, this paper propose a method to realize intensity map rapidly:use images reflecting earthquake disaster which includes photos,the UAV aerial images,remote sensing images and scene intensity value to draw seismic intensity map.Three problems to realize this idea were solved:obtaining images required,image registration and evaluating earthquake intensity. Taking Wenchuan Ms8.0earthquake for example,we realized the thought.On the basis of the typical buildings damage characteristics in North-South earthquake belt, we adopt the kilometer grid data of the project 《Huge damage area fast locating and the disaster distribution key technology research》,combined with vulnerability matrix, loss ratio and the unit price of the buildings, to draw buildings’s loss distribution map of different intensities and calculate different buildings’s loss caused by Wenchuan Ms8.0earthquake in Sichuan province.Likewise,we evaluated earthquake loss caused by another two earthquakes:Ms5.8Yingjiang earthquake on March10,2011and Ms7.0Lushan earthquake on April20,2013.Still we drew loss distribution map of different damage buildings and calculated economic loss.The results suggest:1、 The method of fast obtaining earthquake intensity map in this paper is much more quickly than that after field investigation, and more accurately than that of historical experience isoseismal line model. It is simple and clear which meets the requirements of earthquake emergency rescue and save time and manpower.2、 Appling the population, economic, house data based on the kilometer gird to fast earthquake damage losses assessment, which switches the administrative unit to kilometer grid not only reduced the data distribution error caused by administrative region division, but more actually. Therefore, it can greatly narrow the evaluation error and provide the basis for emergency relief more effectively.3、 The paper experimentalized three typical earthquakes in North-South seismic belt, proved the feasibility of the fast earthquake damage assessment based on kilometer grid in the study area, and achieved good results. The assessment accuracy is higher than before that can meet the requirement of the earthquake emergency relief.