1 23 Arabian Journal for Science and Engineering ISSN 1319-8025 Volume 40 Number 3 Arab J Sci Eng (2015) 40:735-746 DOI 10.1007/s13369-014-1540-6 A Deep Catastrophic Failure Model of Hillslope for Numerical Manifold Method and Multiple Physics Computation Hsueh-Chun Lin, Yao-Chiang Kan, Wen-Pei Sung & Yao-Ming Hong