Spatial analysis of damaged vegetation in the Mianyuan River basin after the Wenchuan Earthquake
H. Z. Zhang1,2,3, J. R. Fan2, X. M. Wang1,3, T. H. Chi1, and L. Peng11Institute of Remote Sensing and Digital Earth, Chines Academy of Sciences, Beijing, 100101, China 2Institute of Mountain Hazards and Environment, Chines Academy of Sciences, Chengdu, 610041, China 3University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
Received: 03 Apr 2015 – Accepted for review: 19 Apr 2015 – Discussion started: 11 May 2015
Abstract. The 2008 Wenchuan earthquake destroyed large areas of vegetation. Presently, these areas of damaged vegetation are at various stages of recovery. In this study, we present a probabilistic approach for slope stability analysis that quantitatively relates data on earthquake-damaged vegetation with slope stability in a given river basin. The Mianyuan River basin was selected for model development, and earthquake-damaged vegetation and post-earthquake recovery conditions were identified via the normalized difference vegetation index (NDVI), from multi-temporal (2001–2014) remote sensing images. DSAL (digital elevation model, slope, aspect, and lithology) spatial zonation was applied to characterize the survival environments of vegetation, which were used to discern the relationships between successful vegetation regrowth and environmental conditions. Finally, the slope stability susceptibility model was trained through multivariate analysis of earthquake-damaged vegetation and its controlling factors (i.e. topographic environments and material properties). Application to the Subao River basin validated the proposed model, showing that most of the damaged vegetation areas have high susceptibility levels (88.1% > susceptibility level 3, and 61.5% > level 4). Our modelling approach may also be valuable for use in other regions prone to landslide hazards.
Zhang, H. Z., Fan, J. R., Wang, X. M., Chi, T. H., and Peng, L.: Spatial analysis of damaged vegetation in the Mianyuan River basin after the Wenchuan Earthquake, Nat. Hazards Earth Syst. Sci. Discuss., 3, 3225-3250, doi:10.5194/nhessd-3-3225-2015, 2015.