A systematic framework for early identification and assessment of rockfall disasters in the Nujiang River Valley: A typical Alpine and Gorge Region

Frequent rockfall disasters have long posed a serious threat to the safety of life and property of the people in the Nujiang River Valley in Yunnan Province， China. In the Alpine and Gorge Region (AGR)， traditional methods for rockfall disaster identification and assessment are severely limited. The purpose of this study is to establish a systematic technical process framework for the early identification and assessment of rockfall disasters in typical high-relief environments， using the Nujiang River Valley as a representative case study. It combines InSAR， UAV photogrammetry， and 3D numerical simulation， showcased through a case study from the Nujiang River basin. The results show that， based on surface deformation analysis， the area with obvious deformation in the Nujiang River basin is about 5%， and nine dangerous rockfall source areas are identified and delineated using UAV photography technology. Based on the evaluation method proposed in this paper， four high-hazard areas have been identified directly above residential zones. Additionally， there is one middle-hazard area located in the gully on the north side of the residential area. Four low-hazard areas have been identified， which are primarily situated on both sides of the residential area. Furthermore， this method also provides the key parameters for rockfall prevention， namely a maximum kinetic energy exceeding 400 kJ and bounce heights over 40 meters. This study demonstrates the practical application of the proposed framework in the Nujiang River Basin， offering a replicable workflow for rockfall hazard identification and risk mitigation in AGR settings.