Development of a semi-automatic method based on object-based analysis and data mining algorithm in landslide detection (case study of Mohammad Abad forest watershed in Golestan)

This research aims to develop a semi-automated method based on remote sensing and data mining algorithms on improved images in order to identify landslides in Mohammad Abad forest watershed in Golestan province. This area is prone to landslides due to the special conditions of topography and human manipulations, and every year it causes significant financial losses to residents and infrastructure destruction. In this study, two Gaofen-1 satellite images from June 1402 and March 1401 were used. Due to the different imaging seasons, all the processes were done separately on two images and finally combined for the entire study area. In order to increase the clarity of the images, three image combining methods named Brovey, PCA and Wavelet-PCA were tested. The Wavelet-PCA method was selected as the best method of image synthesis with a correlation coefficient of 97% and the closest entropy value to the original image. In the next stage, 218 landslide cases were recorded in the region through field visits, 70% of which were used for model training and 30% for model validation. Image segmentation was done along with optimization of scale parameter by local variance method and shape and compression parameters by trial and error. The optimal parameters included scale = 33, shape = 0.6 and compression = 0.5. Then the selection of features was done from textural, spectral, height, geometric and auxiliary layers using the random forest method and 16 main features were selected from among the 53 extracted features. Finally, the selected images were