九寨沟震区地表形变监测及震损物源估算

地震及其次生地质灾害（滑坡、崩塌、泥石流等）引发的松散物质（即震损物源）剧烈迁移会给震区环境与安全造成极为深远的影响。“8·8”九寨沟地震发生后，大量的震损物源加剧了九寨沟景区地质灾害易发性及湖泊淤积风险。获取震损物源的分布与数量，是减少灾害风险与保护湿地景观的基础。因此，利用DInSAR技术实施地表形变监测,基于形变数据，再结合光学遥感数据解译和实地观测，估算九寨沟景区震损物源，解析空间分布与数量特征。研究结果显示:地震在震中的西北侧造成了较大的沉降形变，在震中东南侧也产生了轻微隆起形变，雷达视线向形变量达-23～11 cm；景区震损物源呈带状分布,沿沟谷和道路较为发育，以五花海区域最为集中，估算数量达1.658×105m³。研究结果将为九寨沟景区地质灾害隐患的监测防治及河湖湿地的绿色防淤提供支撑。

Detecting Surface Deformation and Calculating Colluvial Materials: the Case of the 2017 Jiuzhaigou Earthquake

The loose materials movement caused by earthquakes and secondary geohazards endanger residents and threaten the ecological environments. In 2017, the Jiuzhaigou earthquake had produced large amounts of loose materials (colluvial materials) that were still present on the steep slopes and in the valleys. The colluvial materials had aggravated the risks of future geohazards and caused siltation in the Jiuzhaigou Reserve; strong rainfalls can eventually develop devastating debris flows. In response, this research seeked to calculate the volume of earthquake-triggered colluvial materials and analyzed their spatial distribution patterns to help to implement proper early warning systems, prevent, and mitigate geohazards and prevent siltation in future. For this purpose, the researchers applied the DInSAR technique, remote sensing, and conducted some field trips to detect the surface deformation, calculated the volume and spatial distribution patterns, and interpreted their findings. Results showed that the Jiuzhaigou earthquake produced large deformations on the northwest of its epicenter, and small deformations on the southeast of the epicenter, ranging from -23 cm to 11 cm in the satellite Line of Sight. Results revealed that the earthquake-triggered colluvial materials in the Jiuzhaigou Reserve have zonal distribution features, mainly distributed along the roads and valleys, especially in the Wuhuahai area, with a calculated volume of 1.658×105m³. In fact, these findings had great significance for the mitigation on geohazards risks and lakes siltation in Jiuzhaigou Reserve.