This paper took a subregion in a small watershed gully system at Beiyanzikou catchment of Qixia, China, as a study and, using object-orientated image analysis (OBIA), extracted shoulder line of gullies from high spatial resolution digital orthophoto map (DOM) aerial photographs. Next, it proposed an accuracy assessment method based on the adjacent distance between the boundary classified by rem...

The Piedmont region in the United States has been eroded and gullied due to deforestation and cultivation during the 1700 and 1800. Currently, a majority of these gullies are under forest vegetation and appear stable; however, neither the hydrology of these gullies, nor their sediment contribution to surface waters, has been quantified. This study instrumented eight gullies ranging in size from...

Introduction: Gullies were first noted in Mars Orbiter Camera images [1] and have since been found to be commonplace throughout the mid-latitudes on Mars [e.g. 2]. These features are often associated with the action of liquid water, either as unconcentrated water flow or debris flow [e.g., 3,4]. The fact that gullies are found predominantly in the mid-latitudes and have a pole-facing preference...

Introduction: Gullies, a class of unusually young features on Mars consisting of an alcove, a channel and a fan, were initially interpreted to have originated through processes related to the presence of liquid water, primarily through groundwater discharge [1,2]; the current metastability of liquid water on the surface of Mars generated a host of alternative explanations for the gullies [see s...

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...

0019-1035/$ see front matter Published by Elsevier doi:10.1016/j.icarus.2009.06.018 * Corresponding author. E-mail address: [email protected] (J.L. Dickson) Gullies are extremely young erosional/depositional systems on Mars that have been carved by an agent that was likely to have been comprised in part by liquid water [Malin, M.C., Edgett, K.S., 2000. Evidence for recent groundwater seepage a...

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. ...

As an attempt to improve the performances of multi-entry gullies with applications to drainage system of a building, the hydrodynamic characteristics of air-water flows through the gullies with and without swirl generation vanes (SGV) are experimentally and numerically examined. With the aid of present Charge Coupled Device (CCD) image and optical systems for experimental study, the mechanism o...

[1] Recent gullies on Mars are suspected to be the result of liquid‐water‐bearing flows. A formation from wet flows has been challenged by studies invoking granular (dry) flows. Our study focuses on the sinuous shapes observed for some of the recent Martian gullies. Sinuous gullies are found in locations and slopes (of 10°–15°) similar to straight gullies, and they are therefore related to the ...

A new survey of Mars Orbiter Camera (MOC) narrow-angle images of gullies in the 30◦–45◦ S latitude band includes their distribution, morphology, local topographic setting, orientation, elevation, and slopes. These new data show that gully formation is favored over a specific range of conditions: elevation (−5000 to +3000 m), slope (>10◦), and orientation (83.8% on pole-facing slopes). These dat...