Steep topography on the ocean bottom, when underneath an oscillating tide, is not only associated with significant internal wave generation at the tidal frequency but also nonlinear flow features, large overturns and turbulent flow. Here, we investigate the internal wave dynamics and turbulence at an isolated steep obstacle using a three-dimensional, high-resolution large eddy simulation (LES)....

The disease environment in general, and malaria in particular, could help explain underdevelopment in many regions of the world, especially in Africa. Using data from Ethiopia, this paper provides evidence that local malaria risk is associated with worse local development outcomes. By combining information from a large-scale Ethiopian household survey with satellite-derived topographical inform...

Clinoforms on coasts exposed to ocean waves form from sand exported from the shoreface during extreme wave conditions and deposited where wave action diminishes. Elsewhere, it is shown that, during upper 5-percentile wave conditions, wave-induced shear stresses exceed the sediment threshold of motion to below the clinoform rollovers. Experiments and theory suggest that, where bed sediments are ...

the rate of soil erosion and sediment yield estimation in the catchment areas is considered as an important factor for soil and water conservation practices. due to difficulties and restrictions in common soil erosion methods, applying a high accuracy method with lowest cost and time consuming would be necessary. assessment of soil loss in hilly areas with capacity of rang land that has changed...

Eighteen profiles of ∼N-S-trending topography from the Mars Orbiter Laser Altimeter (MOLA) are used to analyze the shape of Mars’ northern hemisphere. MOLA observations show smaller northern hemisphere flattening than previously thought. The hypsometric distribution is narrowly peaked with > 20% of the surface lying within 200 m of the mean elevation. Low elevation correlates with low surface r...

Using spheropolygon-based simulations and contact slope analysis, we investigate the effects of surface topography and atomic scale friction on the macroscopically observed friction between rigid blocks with fractal surface structures. From our mathematical derivation, the angle of macroscopic friction is the result of the sum of the angle of atomic friction and the slope angle between the cont...

The topography of inland deltas is influenced by the water-sediment bal-3 ance in distributary channels and local evaporation and seepage rates. In this 4 letter a reduced complexity model is applied to simulate inland delta forma-5 tion, and results are compared with the Okavango Delta, Botswana and with 6 a laboratory experiment. We show that water loss in inland deltas produces 7 fundamental...

the study was carried out to investigate the effective soil and topographic features on distribution of plant types in sanib taftan watershed in sistan-and-balouchestan province, iran. initially, land units map was specified by combining three maps of slope, aspect and altitude. five types including artemisia santolina- hammada salicornica, artemisia sieberi- amygdalus lycioides, artemisia lehm...

Abstract. Satellite radar altimetry has been an important tool for cryospheric applications such as measuring ice-sheet height or assessing anomalies in snow and ice properties (e.g. the extensive melt Greenland 2012). Although accurate measurements are key applications, slope-induced errors due to undulating topography within kilometre-wide beam-limited footprint can cause multi-metre errors. ...

Abstract We use a mathematical model to investigate the effect of basal topography and ice surface slope on transport deposition sediment within water-filled subglacial channel. In our model, three zones different behaviour occur. zone furthest upstream, variations in lead under wide range conditions. this first zone, even very small gradually varying undulations (~5 m amplitude) can modelled D...