Wenchuan Earthquake

8.0 Richter Magnitude

is the most destructive

most widely-spread and the one entails the most difficulties in disaster-relief since the founding of People’s Republic of China.Along with the earthquake

many secondary disasters

such as mountain collapses

landslides and debris flows and dammed lakes occurred and enlarged the disaster.After the earthquake

National Disaster Reduction Committee（NDRC）and Ministry of Civil Affairs（MCA）triggered the domestic and international satellite remote sensing data achieving mechanism immediately

including the International CHARTER Space and Major Disasters.The achieved data were used for the continuous disaster monitoring and urgent disaster assessment

and provided effective information in disaster relief.This paper establishes an urgent assessment method for catastrophe

which is based on the interpretating with remote sensing data and the deducting by spatial analysis.Taking the urgent assessment using remote sensing data during the Wenchuan Earthquake as an example

this paper apply the method into the assessment for the 152 counties of Sichuan

Shanxi and Gansu provinces.The results show that buildings are destroyed seriously

and the affected population distribute in a very wide area.In general

the disaster loss is distributed corresponding to the fault zone.The disaster loss in mountain area is larger than that in plain area

and the damage in village area is more serious than that in urban area.Wenchuan

Beichuan

Qingchuan

and Mianzhu and other 8 counties in Sichuan province are the most seriously damaged counties.Wen County in Gansu province and Mian county in Shan’xi province are serious damaged.By validation with field investigation

the efficiency of the assessment was approved.The paper developes a step-by-step collection method of assessment

which takes the advantage of the remote sensing data and meets the efficiency need of urgent disaster assessment.The method is also useful for the coordinative operation and comprehensive assessment.The method is scientific

applicable

and feasible in disaster assessment with remote sensing data during catastrophe.