A dasymetric data supported earthquake disaster loss quick assessment method for emergency response in China

Abstract

Abstract. Improving earthquake disaster loss estimation speed and accuracy is one of key factors in effective earthquake response and rescue. The presentation of exposure data by applying a dasymetric map approach has good potential for addressing this issue. With the support of 30'' × 30'' areal exposure data (population and building data in China), this paper presents a new two-phase earthquake disaster loss estimation method for emergency response situations. This method has two phases: a pre-earthquake phase and a co-earthquake phase. In the pre-earthquake phase, we pre-calculate the earthquake loss related to different seismic intensities and store them in a 30'' × 30'' grid format, which has four stages: determining the earthquake loss calculation factor, gridding possible damage matrixes, the building damage calculation and the people loss calculation. The dasymetric map approach makes this possible. Then, in the co-earthquake phase, there are two stages of estimating loss: generating a theoretical isoseismal map to depict the spatial distribution of the seismic intensity field; then, using the seismic intensity field to extract statistics of disaster loss from pre-calculated loss estimation data to obtain the final estimation results. The method is validated by four actual earthquakes that occurred in China. The method not only significant improves the speed and accuracy of loss estimation, but gives spatial distribution for the loss, which will be effective in aiding earthquake emergency response and rescue. Additionally, related pre-calculated earthquake loss estimation data in China could serve to provide disaster risk analysis before earthquakes happen. Currently, the pre-calculated loss estimation data and the two-phase estimation method are used by the China Earthquake Administration.

Post-Earthquake People Loss Evaluation Based on Seismic Multi-Level Hybrid Grid: A Case Study on Yushu Ms 7.1 Earthquake in China

“…The values of regional intensity often decrease as the distance from the epicenter increases, and the relationship between distance and intensity can be expressed by using a seismic isoseismal map. A seismic isoseismal map is a continuous planar intensity map that illustrates the spatial distribution of a seismic intensity eld [15]. Seismic intensity at any point in a disaster area can be obtained from the seismic isoseismal map, which is considered a hazard map used to depict the seismic eld of in uence of the earthquake.…”

“…The damage level of buildings (j) is categorized as basic intact (B i ), slight damage (S l ), moderate damage (M d ), severe damage (S d ), and complete damage (C d ). Seismic intensity (I) in DPM ranges from VI to X because the damage caused by an earthquake with a seismic intensity of less than VI is low and thus not considered in the evaluation, although the seismic intensity ranges from I to XII based on the Seismic Intensity Scale of China [15]. Moreover, an earthquake of a seismic intensity XII has not been recorded in China.…”

“…However, due to a large land territory of administrative units, such as in China, it is a common situation that only a component of administrative regions is a ected in one earthquake event. Therefore, an erroneous evaluation result may be obtained and inappropriate rescue decisions may be implemented when exposure data of an entire administrative area is used [15]. For example, Qinchuan county was not provided with an appropriate rescue level after Wenchuan earthquake occurred in China.…”

“…With a high-precision grid, the e ciency of seismic damage assessment can be improved [15]. In existing SIG-based methods, an entire disaster region is divided into several grid units, which exhibit same shapes and sizes, and seismic intensity and exposure information are assumed to be evenly distributed within a grid unit.…”

Rapid Loss Assessment for Earthquake Disaster Based on AHP and Case Matching

“…Earthquake is one of the most serious natural disasters in the world [1]. For example, the 1994 Northridge earthquake in the USA caused 12.5 billion USD insurance losses [2]; the 2003 Bam earthquake in Iran resulted in more than 30 000 deaths [3]; the 2008 China Wenchuan earthquake (Ms8.0) had 69,142 death tolls.…”