The streambed median grain size (D50) has been an integral part of many sediment transport and stream power equations seeking to characterize channel stability conditions. However, its previous usage is constrained by regional applicability, localization datasets, a limited number data points. This study uses large geographically diverse set (n > 2400), from five published sources, present q...

Introduction. FIDO is the prototype rover for the Mars 2003 mission, complete with an Athena-like science payload [1]. FIDO will be deployed in April 1999 for a series of tests at Silver Lake, CA [2]. In preparation for these tests, we have examined a suite of rocks collected at the site to anticipate the problems expected in field analyses on available rock surfaces as opposed to surfaces that...

USDA Forest Service Res. Note PSW-RN-414-WEB. 1993. E xperienced hydrologists and geomorphologists can estimate the relative mobility of a streambed by looking at indicators of bedload transport, such as the freshness of bed-surface material. Another such indicator is the amount of fine sediment in pools. Pools in gravelbed streams commonly contain deposits of fine sediment (mostly sand and gra...

An Unattainable Salvation Dirt, Danger & Domesticity in Old New York It was 1832, and in the Five Points area of New York, a great street excavation was under way. What would cause such a flurry over the cobbles? Here, shovels plied the earth decades before the subway tunneled beneath the crowded streets. Electrical poles and telegraph lines had yet to become a nuisance worthy of inhumation. No...

The cave’s physical environment can be affected by tourism activities but only a few studies evaluated how recreational use may affect the cave fauna, mainly in caves with low number of visitors per year. To test hypothesis that led to changes habitat structure and invertebrate diversity, distinct scales along were analyzed. Distinct areas without human visitation analyzed transects (10 x 3 m) ...

The hydraulics of steep mountain streams differ from lower gradient rivers due to shallow and rough flows, energetic subsurface flow, and macro-scale form drag from immobile boulders and channel and bed forms. Heightened flow resistance and reduced sediment transport rates in steep streams are commonly attributed to macro-scale form drag; however, little work has explored steep river hydrodynam...