A Remote sensing-based approach for debris-flow susceptibility assessment using artificial neural networks and logistic regression modeling

Efforts to map the distribution of debris flows, to assess the factors controlling their development, and to identify the areas susceptible to their occurrences are often hampered by the paucity of monitoring systems and historical databases in many parts of the world. In this paper, we develop and successfully apply methodologies that rely heavily on readily available remote-sensing datasets over the Jazan province in the Red Sea hills of Saudi Arabia. A fivefold exercise was conducted: 1) a geographical information system (GIS) with a Web interface was generated to host and analyze relevant coregistered remote-sensing data and derived products; 2) an inventory was compiled for debris flows identified from satellite datasets (e.g., GeoEye, Orbview), a subset of which was field verified; 3) spatial analyses were conducted in a GIS environment and 10 predisposing factors were identified; 4) an artificial neural network (ANN) model and a logistic regression (LR) model were constructed, optimized, and validated; and 5) the generated models were used to produce debris-flow susceptibility maps. Findings include: 1) excellent prediction performance for both models (ANN: 96.1%; LR: 96.3%); 2) the high correspondence between model outputs (91.5% of the predictions were common) reinforces the validity of the debris-flow susceptibility results; 3) the variables with the highest predictive power were topographic position index (TPI), slope, distance to drainage line (DTDL), and normalized difference vegetation index (NDVI); and 4) the adopted methodologies are reliable, cost-effective, and could potentially be applied over many of the world's data-scarce mountainous lands, particularly along the Red Sea Hills.