Application of photogrammetry to the field observation of failed slopes

This report analyses the accuracy and applicability of aerial photogrammetry to the study of erosion. The study presented in this report uses aerial photogrammetry to study the distribution characteristics of materials from failed slopes in steep mountainous areas where there is frequently slope failure. The topography of the area consists of cataclastic and hydrothermally altered soft granite and fresh granite. Aerial photogrammetry was used to study slopes with active production of materials through erosion, locations where eroded materials accumulate, and how the eroded materials are washed away by rainfall. The use of aerial photogrammetry was effective in gaining an understanding of the movement of eroded earth and sand. Furthermore, the quantitative results obtained through aerial photogrammetry were compared with quantitative results obtained from measurements using observation piles, giving very close results. Since they match the results of existing literature, aerial photogrammetry is also thought to be reasonably accurate. The results of this research shows that the accuracy of aerial photogrammetry is sufficient for field observations of slopes with fairly active erosion.