Generalized Additive Model for Spatial Analysis of Mass Movements Susceptibility

Abstract

This paper analyzes spatial distribution of mass movements susceptibility from Luís Alves watershed, Santa Catarina State, Brazil. The modeling framework adopted in this research is based on spatial point processes, which defines a susceptibility measure that varies continuously over the study region and is estimated by means of generalized additive modeling methods. In this paper, the mass movements susceptibility is quantified by probability levels. The procedure employed allows susceptibility factors to be incorporated into the model in a simple way and easy interpretation. The procedure also allows the construction of maps with tolerance contours which help identify areas of significantly high/low susceptibility and an overall test for the null hypothesis of constant risk over the region. The application of the model to the data of susceptibility to mass movements, presented results consistent with the geomorphology of the study region, showed that the spatial variation in the susceptibility is significant, and pointing a way to the advance of monitoring and decisions making support systems.