Despite considerable attention, the long-term impact of rivers on species diversification remains uncertain. Meander loop cutoff (MLC) is one river phenomenon that may compromise a river's diversifying effects by passively transferring organisms from one side of the river to the other. However, the ability of MLC to promote gene flow across rivers has not been demonstrated empirically. Here, we...

in semi arid area geomorphological impacts of dams are very major. dams, as man- made structures, have major impacts on river hydrology, primarly through in the timing, magnitude, and frequency of low and high flows, ultimately producing a hydrologic regime differing significantly from the pre-impoundment natural flow regime. despite the profiles of dams on river regulation for water resources ...

Riparian forest vegetation is widely believed to protect riverbanks from erosion, but few studies have quantified the effect of riparian vegetation removal on rates of river channel migration. Measured historical changes in a river channel centreline, combined with mapped changes in floodplain vegetation, provide an opportunity to test how riparian vegetation cover affects the erodibility of ri...

Venusian lava channels have meander dimensions that relate to their mode of formation. Their meander properties generally follow terrestrial river trends of wavelength (L) to width (W) ratios, suggesting an equilibrium adjustment of channel form. Slightly higher L/W for many Venusian channels in comparison to terrestrial rivers may relate to nonaqueous flow processes. The unusually low L/W valu...

meanders are among the important characteristics of some rivers that flow in semi-arid regions. swift displacement along the river's flow, change in the location of the central ridge and bank erosion leateral erosion are resulted from making meander in the river's flow. meanders in river courses on north east slopes of sahand (located in 46ëš 43ì to 47ëš 15ì e and from 36ëš 05ììì...

karun river with a length of about 890 km is considered as a main river in the country. in this paper, types of karun’s screws regarding to the geometric factors of radius of curvature and chord length were identified by fitting circles with the arcs of the river’s axis. river’s arcs were classified into simple and compound screws. then, by formation of the database consist of topographic...

The long-term discharge evolution of branches of rivers can potentially be derived from inactive and fossil river meanders using relations between discharge and channel width and meander dimensions. This evolution is relevant for the understanding of river dynamics and avulsion, and the resulting changes of downstream flooding risks and shipping conveyance. Unfortunately, digitalisation of infi...

We review a number a recent advances in the study of two-dimensional statistical models with strong geometrical constraints. These include folding problems of regular and random lattices as well as the famous meander problem of enumerating the topologically inequivalent configurations of a meandering road crossing a straight river through a given number of bridges. All these problems turn out t...