Application of remote sensing technology in emergency rescue decision about “6·17” Danba River debris flow disaster chain

On June 17, 2020, a mudslide occurred in Meilongou of Banshanmen Town, Danba County of Sichuan Province, which blocked Xiaojinchuan River and formed a barrier lake, causing heavy property losses and casualties. In order to grasp the first-hand disaster situation and assist emergency rescue and other disposals, combined with the UAV aerial photography data and post-disaster site survey and other data, the authors used the domestic high-score 2 satellite data as the main data source to carry out the emergency investigation and analytical research of emergency rescue decision about “6.17” Danba River debris flow disaster chain. The results show that the affected population is about 65,000 and the nearest emergency rescue teams are from State Grid Danba County Power Supply Company and China Unicom of Xiaojin Country. Five schools, such as Banshanmen middle school, could be used as temporary resettlement shelters. There are six mining enterprises, one important reservoir and one hydropower station affected by the disaster. The debris flow gully is NE—SE distributed, covering about 142,700 m². And the barrier lake is about 1.03 km², covering 498,000 m². The totally destroyed roadbed and road surface were about 2.1 km and there are 9 suspected disaster hidden dangers in the lower reach. Whats more, 25 residential houses and 5 bridges were damaged by the disaster. Two rescue lifelines with good post-disaster accessibility to the severely affected debris flow areas were chosen. With the help of remote sensing technology, the in-depth analysis of the pre-judgment of the affected population by the debris flow disaster chain, emergency investigation of the disaster situation and disaster damage, and the selection of emergency rescue lifelines were successfully conducted, which has great guiding significance in the emergency rescue and disaster prevention and mitigation in the mountainous areas of Southwest China with similar geological conditions.