J. Earth Syst. Sci. (2020) 129 30 Ó Indian Academy of Sciences https://doi.org/10.1007/s12040-019-1277-4 (0123456789().,-volV)(0123456789().,-volV) Susceptibility assessment of rainfall induced debris flow zones in Ladakh–Nubra region, Indian Himalaya HSNEGI*, ANANT KUMAR,NNARASIMHA RAO,NKTHAKUR, MSSHEKHAR and SNEHMANI Snow and Avalanche Study Establishment, Him-Parisar, Sector-37A, Chandigarh 16036, India. *Corresponding author. e-mail:
[email protected] MS received 17 April 2019; revised 29 July 2019; accepted 4 August 2019 In recent past, rainfall-induced debris flow events in Ladakh–Nubra region have caused loss of lives and damages to civil infrastructures and army locations. Therefore, there is a need of high spatial and temporal monitoring of precipitation, and further to assess susceptible rainfall-induced debris flow zones in the area. We assessed the rainfall data collected at two gauge stations and observed a significant increase in the rainfall amount over the study region during summer-monsoonal period 1997–2017. Increasing trend was also observed from CRU gridded precipitation dataset. A GIS-based multi-criteria evaluation (MCE) method was performed by combining topographical, environmental and hydrological parameters for mapping of rainfall-induced susceptible zones. Suitability analysis of precipitation fore- casts from WRF model at higher resolution (3 km) was also performed. A good agreement (r = 0.76) was observed between 4-day model forecast and field observed rainfall. Further, the simulated precipitation from WRF was incorporated into GIS model for assessment of debris flow susceptible zones for two cases of heavy precipitation events. The modelled high, medium, low and very low risk susceptible zones identified for the year 2015 events are validated with field survey and pre-post satellite imageries, and found in good agreement (ROC = 76.6%).