Structure-from-Motion Multi-View Stereo (SfM-MVS) photogrammetry has become one of the popular methods widely applied in various geomorphological studies. Unlike the orthodox photogrammetry, the data processing of SfM-MVS photogrammetry is more straightforward allowing instantaneous acquisition of high-resolution, accurate topographic data based on varying platforms including small Unmanned Aerial Vehicle (UAV). Here we review the basics and applications of SfM-MVS photogrammetry to discuss the efficiency and possibilities of the innovative approach in geomorphology, particularly focusing on the slope (mass movements), fluvial, coastal, and volcanic processes, with additional examples in glacial/periglacial and tectonic applications. We also discuss issues on the SfM-MVS methodology including its coverage area, resultant data resolution, acquisition frequency, and accuracy/quality assessment, as well as the future of the SfM-MVS approach in geomorphology.

Sand ribbons, which are longitudinal bedforms formed by unidirectional flows, appeared on an athletic field on the flood channel of the swollen Kizu River, Kyoto, Japan, in September of 2012 and 2013. We made the following observations of the sand ribbons and associated fluvial bedforms; (1) Furrows were distributed upstream of the sand ribbons; “in-line ripples”, newly defined here, were superimposed on the sand ribbons where antidunes had formed in an upper flow regime, and sand patches, sand sheet, and the transverse bedforms of 3D (e.g., barchanoid, lunate, and linguoid) and 2D dunes were distributed downstream of the sand ribbons. (2) The distribution pattern shows that the sand ribbons formed on a flat substrate where the supply of sand was limited in an upper flow regime. (3) The bedform distribution pattern reminds us traffic flow patterns. Transported sediments can take congested, “jammed” or free phases, depending on the flux and density of sediments. During the free phase, furrows, sand ribbons, sand sheets and sand patches form in that order as flux and density increase. The congested to jam phases are characterized by ripples, dunes, and sand ridges.

Jamuna is a large sand bedded braided river of Bangladesh which leaves significant amount of sand bars along the river course. The main objective of this work is to quantify the potential economic minerals and rare earth materials from a specific river bar of Jamuna River and to infer the presence of similar materials in similar environment of deposition through geomorphic point of view. The case study deals with the identification and quantification of average concentration of dominant heavy minerals which are economically important. Heavy liquid and mechanical separation, and microscopic observation followed by X-ray analytical techniques were performed to determine heavy and light mineral percentage in raw sand as well as presence of other important elements including rare earths in those minerals. The physical separation results showed the presence of approximately 20 % heavy minerals which were identified as ilmenite, magnetite, garnet, rutile, amphibols, pyroxene, kyanite, epidote, tourmaline, zircon, monazite, etc. Such heavy mineral concentrations in Jamuna River indicate that fluvial bars of Bangladesh can be a potential place of economic mineral deposition. Analytical analysis revealed that several trace metals and rare earth elements like strontium, thorium, yttrium, niobium, cerium, neodymium, erbium etc. are present in considerable amount. Geomorphological prospecting could be a potential technique to explore the similar kind of depositions in other parts of the river. Defining such deposits and exploitation of economic minerals from those areas could be helpful for flood hazard mitigation.

Lake Biwa is the largest and longest-lived lake of fresh water in Japan. Its environment changes have been recorded in the bottom sediments. To elucidate relationship between fossil diatom assemblages and climate conditions in Lake Biwa, we performed diatom analysis for the surface sediments, associated with water content, total organic carbon, total nitrogen, Cs-137, and Pb-210 measurements. Temporal changes of fossil diatom assemblage were revealed in intervals of 1 to 3 years for the past 50 years, and 4 diatom zones were recognized on the basis of CONISS cluster analysis. Zone 1 (before AD 1973) is characterized by dominant Stephanodiscus suzukii associated with Aulacoseira nipponica and lack of Fragilaria crotonensis. Zone 2 (AD 1973-1986) is dominated by Aulacoseira nipponica with S. suzukii.. Zone 3 (AD 1986-1996) is characterized by predominance of S. suzukii and Zone 4 (AD 1986-2012) is shown by increase of Fragilaria crotonensis. Increasing of F. crotonensis seems to relate with warm temperature higher than 14℃. Abundance of Aul. nipponica has positive relation to low winter temperature and high winter precipitation. S. suzukii seems to be favorable for intermediate temperature. These relationships suggest that temporal change of fossil diatom assemblage might be controlled by climate changes in the late Quaternary.

Recently, topographic surveying using UAV and SfM-MVS has been attracting attention. These have made it possible to obtain DSM (Digital Surface Models) with a high time and spatial resolution. In this study, we will attempt to prove the work efficiency of surveying conducted using the UAV/SfM-MVS system. The results demonstrated that DSM resolution is only affected to flight altitude, provided that the parameters of the SfM software aren’t changed. In advance, it is necessary to predict the desired resolution and conduct a UAV flight. The position of the GCP has the most significant effect on the accuracy of the DSM. GCP influences the assumed position of camera shooting as estimated by SfM. When giving the GCP, in order for the object to be interpolated it is desirable to give the highest and lowest points of what you want to be captured. In the future, it is necessary to aim for improved efficiency in surveying methodology through further experiments and improved understanding of the principles of SfM-MVS software.