Structure from Motion with Multi-View Stereo photogrammetry (SfM-MVS) is increasingly used in geoscience investigations, but has not been thoroughly tested in gullied savanna systems. The aim of this study was to test the accuracy of topographic models derived from aerial (via Unmanned Aerial Vehicle, ‘UAV’) and ground-based (via handheld digital camera, ‘ground’) SfM-MVS in modelling hillslope...

The tall-grass prairies, wetlands and forests that dominated the Iowa landscape have been replaced by annual row-crops and grass pastures that occupy more than 90 % of the landscape today. Because of these changes water reaches the streams and gullies much faster and has led to incised streams and an extensive growth of gully networks. Stream and gully banks are major contributors of the nonpoi...

understanding the development of gully volumes requires the empirical relations between gully volume (v) and length (l) to be established in the field. so far, such v–l relations have been proposed for a limited number of gullies/environments and were especially developed for ephemeral gullies.in this study, v–l relations were established for ephemeral gullies in southern ilam. in order to take...

introduction: gully erosion is an important type of soil erosion in iran and ardebil province (moghimi and salami, 2011; khatibi, 2006). increasing the cross section of gullies is an indicator for gully developing (deng et al, 2015). topography and soil properties are two important factors in gully developing in various regions of worldwide (poesena et al, 2003). despite the importance of soil ...

negative impacts of gully erosion in marly areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. the objective of this research was to evaluate gully thresholds related to plant vegetation cover and landuse change in the agriculture (ag), fair rangeland (fr) and weak rangeland (wr) areas of ghaasr-e-shirin, kermanshah, i...

Introduction: The discovery of abundant, geologically recent gullies on Mars in Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images [1] has led to numerous studies examining potential mechanisms for recent fluid or fluid-rich surface processes [e.g., 1-2]. The process or processes involved in Martian gully formation provide important insights into Martian geologic and volatile history. ...

Introduction: The latitude dependent distribution [1-3] and non-uniform orientations [4-8] of young gullies on Mars suggest that their formation and modification are controlled by the activity of volatiles at or near the surface. Given the relative abundance of gullies and Mars' current thermal environment, CO 2 and H 2 O are the most likely candidates for contributing to gully evolution. Conte...

Introduction: Current temperature and pressure conditions on Mars suggest that liquid water is unstable at the surface with respect to boiling and freezing. However, gully features, generally consisting of alcoves , channels, and debris aprons and existing in a band at mid latitudes mainly in the southern hemisphere with a possible preference for pole-facing orien-tations [1, 2], suggest liquid...

Introduction: Gully features were first observed in the images taken by MOC in impact craters, south polar pits and large martian valleys [1], tending to midlatitudes [2]. HiRISE imagery supports the conclusion that the gullies were formed by fluvial erosion [3], but the source and composition of this fluid is unclear. The superposition of the gully aprons over aeolian features, e.g. dunes, sug...