Landslide Hazard Assessment Using UAV Imagery and GIS for Road Planning and Development in Chure Area: Sindhuli-Hetauda Section

Nepal, constantly ranked as one of the most disaster-prone countries, has a high risk of landslides. This study aims at creating the hazard map, landslide inventory map and designation of hazard levels along ~100Kms of Sub-Himalayan road in four of the most crucial sites. Unmanned Aerial Vehicles (UAVs) as the primary means of for carrying out the topographical survey, used the Digital Surface Model (DSM) and the orthomosaic map. The Root Mean Square Error (RMSE) of the survey for the individual sites were found to be 0.001m, 0.045 m, 0.044 m and 0.804 m respectively. A detailed topographical map of the area was created, along with the hazard map. Furthermore, the hazard levels for the surveyed area were also obtained: the largest area being medium (60.68%, 57.45%, 71.21% and 71.16 % respectively in Chattiwan, Bhawanchuli, Gurji and Hakpara), followed by high (32.59%, 18.91%, 17.03% and 11.54% respectively in Chattiwan, Bhawanchuli, Gurji and Hakpara), low (6.73%, 23.64%, 11.76% and 17.30% respectively in Chattiwan, Bhawanchuli, Gurji and Hakpara). It was also concluded that the forest area is at high risk followed by the bush and the settlement area in the first, second and the third site (Chattiwan, Bhawanchuli and Hakpara in order), and the cultivable land followed by the bush and the settlement area were found to be in high risks in order in the fourth site (Gurji).