Effect of landslide spatial representation and raster resolution on the landslide susceptibility assessment

The quality of landslide susceptibility assessment is effected by landslide inventory and raster resolution. The point landslide inventory and polygon landslide inventory are usually two spatial representations. The uncertainty to landslide susceptibility result will be induced by different raster resolution and landslide spatial representation. To explore the uncertainty caused by differences in landslide spatial representation and raster resolution, 2 spatial representations (point and polygon) in landslide inventory and 4 raster resolutions (25 m, 50 m, 75 m and 100 m) were introduced in the landslide susceptibility model. A total of 489 landslides with accurate boundary information were obtained in Wanzhou District, Chongqing, China. 5 geo-environmental predictors and random forest model as a data-driven model were used in the landslide susceptibility assessment. The research results demonstrate that (i) in terms of model performance, the prediction performance of polygon models was higher than that of point models by comparing reliability and accuracy. In addition, under the conditions of different base map resolution in the study area, the 25m resolution has a relatively good prediction performance. (ii) In terms of model robustness analysis, the lowest uncertainty was the 25 m resolution model, which has more stable prediction performance. Therefore, the research is useful for selecting the raster resolution and spatial representations in the data-driven landslide susceptibility assessment.