Assessment Of Damaged Areas And Affected Population In Earthquake Disasters Based On Night-time Imageries

Night light is the symbol of human activities: the existence of a light source and light source strength degree representatives the intensity of human activities.At the same time,the light is closely related to power facilities and buildings,if an area suffered from a strong earthquake damage,the information will get clear on the damage scope and degree of lighting performance,especially,for the subject people who are waiting for rescue,it is able to provide the most direct information.So night light images play a vitally significant role for earthquake disaster relief and decision-making.DMSP/OLS night lighting remote sensing images selected by the thesis have the rescue subject-related information advantages over day imageries.Based on that,the thesis selected the major seismic disaster events happened in Japan earthquake in 2011,Wenchuan earthquake in 2008,then carried out data filtering,fast matching,the normalized preprocessing research,which effectively eliminate the influence of non-seismic factors.Then it extracted difference of the night lights change by using two phase,multi-phrase and interpolation of the whole year round light data.The results show that three methods get the similar effect: In east Japan earthquake hard-hit Miyagi,Fukushima and Iwate prefecture,and in the Wenchuan earthquake disaster seriously,Pengzhou,Dujiangyan,Shifang city,Mianzhu city,Anxian county,Wenchuan county,etc.Those tested and verified the correctness of the experiment process,processing method,extraction method.Different extraction methods have different applicable range and precision,which illustrates the light data are feasible to be used to study the influence of the earthquake disaster area.But the extraction also affected by economic development,population environment,natural geographical environment,cloud in the sky and clouds thickness pre-post the earthquake and the influence of sensor detection ability,etc.Finally,it derived and modeled the quantitative relation and population distribution between China's population statistics in 2002-2010 and light data.Combining with the Wenchuan earthquake disaster,the affected area population was estimated by area extraction and the precision was analysed.Accoring to the ratio of damaged area and affected population,the hard hit area,serious area,and the general area were detected.This thesis realized quantitative evaluation of population and its macroscopic distribution in dynamic monitoring,and rapid information support for the decision of earthquake emergency.