基于现场调查的2025西藏定日MS6.8地震房屋震害与人员伤亡分析

doi:10.3969/j.issn.0253-4967.2025.01.005

摘要/Abstract

摘要：

2025年1月7日9时5分, 西藏南部日喀则市定日县发生6.8级地震。此次地震已造成126人遇难, 188人受伤, 大量房屋倒塌。根据现场调查, 土木结构房屋是此次地震中受影响最大, 破坏最严重的房屋类型。地震遇难者集中分布于震中附近的定日县长所乡、措果乡和曲洛乡, 其中长所乡受灾最为严重, 遇难人数占总遇难人数的74.60%。地震破坏力强、村落临近发震断层、房屋建筑抗震性能低、高人员在室率及低温缺氧等是造成此次地震人员伤亡高的主要原因。基于人员伤亡原因分析和现场调查, 文中从加强活动断层探测、提升地震预警能力、降低传统民居震害风险、夯实应急保障措施、防范地震次生灾害风险及加强风险意识宣传教育等6个方面, 提出了针对性地降低西藏地区震害风险、减少人员伤亡的对策建议, 以期为当地防震减灾能力提升和灾后恢复重建提供参考。

关键词: 定日M_S6.8地震, 震害分析, 人员伤亡, 西藏

Abstract:

On January 7, 2025, at 9:05 AM, a magnitude 6.8 earthquake struck Dingri County, Shigatse City, located in the southern part of the Xizang Autonomous Region(28.50°N, 87.45°E), with a focal depth of 10 kilometers. By 7:00 PM on January 9, the earthquake had resulted in 126 fatalities and 188 injuries. A total of 27, 248 buildings were damaged, including 3, 612 collapsed structures. Timely understanding and analysis of the earthquake's damage characteristics and the causes of casualties can provide valuable references for subsequent disaster loss assessments and recovery planning.

Based on field investigations, this study provides a comprehensive overview of the earthquake damage, covering four main aspects: seismic characteristics and affected areas, seismogenic fault and aftershock distribution, building damage and influencing factors, and the distribution and causes of casualties. The study also analyzes in detail the reasons for the severe casualties in this earthquake.

The epicenter of the Dingri earthquake is located within the Lhasa block of the Tibetan Plateau. The earthquake was triggered by the Dengmecuo fault, a normal fault characterized by crustal extension due to fault slip. The maximum intensity of this earthquake reached IX degree, and the major axis of the isoseismal line runs nearly north-south, with a length of 191 kilometers and a short axis of 152 kilometers. The area affected by intensity VI or higher is approximately 23986 square kilometers, covering six counties and 45 towns(or streets)in Shigatse City, Xizang Autonomous Region. The earthquake caused a surface rupture of approximately 26 kilometers, with a maximum vertical displacement of about 3 meters.

Field investigations revealed that the building structures in Dingri County mainly consist of frame, masonry, and traditional civil structures. Among these, traditional civil structures sustained the most severe damage. In extremely and severely affected areas, the majority of civil-structure buildings were either destroyed or severely damaged, with complete or partial collapses occurring. The main factors contributing to the severe damage to civil-structure buildings include the lack of seismic resistance measures, poor construction techniques, and inadequate shear resistance and bond strength of construction materials.

The majority of casualties were concentrated in Changsuo, Cuoguo, and Quluo towns, near the epicenter. Changsuo town suffered the most severe damage, with casualties accounting for 74.60% of the total fatalities. The high casualty rate can be attributed to the strong destructive power of the earthquake, the proximity of villages to the fault lines, low seismic performance of buildings, high population density, and adverse environmental conditions such as low temperatures and oxygen deficiency.

Based on the analysis of the causes of casualties and field investigations, this study proposes targeted countermeasures and suggestions to mitigate earthquake disaster risks and minimize casualties in Xizang. These measures include enhancing active fault detection, improving earthquake early warning capabilities, reducing seismic damage risks to traditional residential buildings, strengthening emergency response measures, mitigating the risk of secondary earthquake disasters, and increasing public awareness of earthquake risks. These recommendations aim to enhance the region's earthquake prevention and mitigation capabilities and provide guidance for post-disaster recovery and reconstruction.

Key words: Dingri M_S6.8 earthquake, earthquake damage analysis, casualties, Xizang

魏本勇, 张钰曼, 石峰, 乔俊香, 王鑫, 张达. 基于现场调查的2025西藏定日M_S6.8地震房屋震害与人员伤亡分析[J]. 地震地质, 2025, 47(1): 64-79.

WEI Ben-yong, ZHANG Yu-man, SHI Feng, QIAO Jun-xiang, WANG Xin, ZHANG Da. ANALYSIS OF BUILDING DAMAGE AND CASUALTIES OF THE 2025 DINGRI M_S6.8 EARTHQUAKE IN XIZANG BASED ON FIELD INVESTIGATION[J]. SEISMOLOGY AND GEOLOGY, 2025, 47(1): 64-79.

图/表 9

图1 西藏定日6.8级地震烈度图

Fig. 1 Seismic intensity map of the MS6.8 earthquake in Dingri, Xizang.

图2 定日6.8级地震区域地震构造与余震分布

Fig. 2 Regional seismic structure and aftershock distribution of the Dingri MS6.8 earthquake.

图3 定日6.8级地震震源机制解图

Fig. 3 Seismic source mechanism solution of the Dingri MS6.8 earthquake.

图4 定日6.8级地震地表破裂(石峰等, 2025)

Fig. 4 Photo showing surface fractures produced by the Dingri MS6.8 earthquake(SHI Feng et al., 2025).

图5 土木结构房屋震害示例 a 长所乡; b 锡钦乡; c 措果乡; d 曲洛乡

Fig. 5 Examples of seismic damage to civil structural buildings.

图6 曲洛乡(a)和措果乡(b)砖混结构震害示例

Fig. 6 Examples of seismic damage to brick concrete structures in Quluo(a) and Cuoguo town(b).

图7 曲洛乡框架结构震害示例

Fig. 7 Examples of seismic damage to the framework structure in Quluo town.

图8 定日地震遇难人员分布

Fig. 8 Location distribution of victims in the Dingri MS6.8 earthquake.

图9 定日地震遇难人员年龄结构

Fig. 9 Plot of victim number with age in the Dingri MS6.8 earthquake.

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