Let P be a set of n objects on a square grid. A push is a transformation of P that involves sweeping a horizontal or vertical line by one unit, starting from the hull of P , displacing objects in the direction of the sweep. For example, when pushing to the right, all the leftmost objects are displaced one unit to the right. This in turn displaces other objects further right. Given P , we want t...

The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flood...

Declines in cottonwood (Populus spp.) recruitment along alluvial reaches of large rivers in arid regions of the western United States have been attributed to modified flow regimes, lack of suitable substrate, insufficient seed rain, and increased interspecific competition. We evaluated whether and how these factors were operating during 1993–1996 to influence demographics of Fremont cottonwood ...

The main purpose of this paper was to evaluate the performance of the triangular vanes located on the bed and their effect on the bed topography considering different flow conditions. For this purpose, tests were carried out on a straight flume for different flow conditions (five Froude numbers of 0.18, 0.20, 0.22, 0.24 and 0.26) by installing a series of triangular vanes at a space of 4Le (Le ...

river banks are exposed to bank erosion and destruction. one of the river engineering goals is to provide human life requirements and reduce river danger. so spreading extent of this phenomenon, whose risk and other important factors must be recognized. using groins is one of the control ways that by accurate design and accurate performance, bank erosion control and field reclamation would be p...

1. introduction floods are among earth's most common and most destructive natural hazards. floods create geomorphic hazards via changes in sediment transport and channel configuration (e.g. channel width, lateral migration, planform changes, etc). in this context, floodplain zoning and its application in spatial planning is important in non- structural measures in order to reducing flood damage...