Articles | Volume 13, issue 11
Nat. Hazards Earth Syst. Sci., 13, 2851–2861, 2013
Nat. Hazards Earth Syst. Sci., 13, 2851–2861, 2013

Research article 15 Nov 2013

Research article | 15 Nov 2013

Pre-, co-, and post- rockslide analysis with ALOS/PALSAR imagery: a case study of the Jiweishan rockslide, China

C. Zhao1,2, Q. Zhang1,2, Y. Yin3, Z. Lu4, C. Yang1,2, W. Zhu5, and B. Li6 C. Zhao et al.
  • 1College of Geology Engineering and Geomatics, Chang'an University, Xian, Shaanxi, 710054, China
  • 2Key Laboratory of Western China's Mineral Resources and Geological Engineering, Ministry of Education, No.126 Yanta Road, Xian, Shaanxi, 710054, China
  • 3China Geological Survey, 45 Fuwai Dajie, Xicheng District, Beijing, 100037, China
  • 4Roy M. Huffington Department of Earth Sciences, Southern Methodist University, Dallas, Texas, USA
  • 5Department of Land Surveying and Geo-Informatics, Hong Kong Polytechnic University, Hong Kong, China
  • 6Institute of Geomechanics, Chinese Academy of Geological Sciences, South Road, Minzuxueyuan, Beijing, 100081, China

Abstract. On 5 June 2009, a catastrophic rockslide debris flow occurred at the crest of the Jiweishan range, Chongqing Municipality, China, killing 74 people and injuring an additional eight. We use L-band ALOS/PALSAR imagery to address landslide processes before, during and after the slide. We employ three different SAR methods, i.e., short baseline subsets (SBAS) interferometric SAR (InSAR), SAR backscattering intensity change, and InSAR stacking algorithm, to study any ground deformation before the rockslide, investigate the affected area, and calculate the topographic change by this slide, respectively. First, continuous deformation has been observed based on the available ALOS/PALSAR InSAR imagery during June and December 2007. Second, the area affected by the landslide can be inferred based on changes in SAR backscattering intensity as well as surface topography, with an estimated area of 0.47 million m2. Last, an InSAR-derived post-slide digital elevation model has allowed us to estimate surface height changes due to the slide, reaching about −80 m at the source region and about 60 m in the deposit region, respectively. Our InSAR-derived estimates have been validated using in situ data and 3-D lidar measurements.

Final-revised paper