Influence Of Water Flow Research Articles

Influence of Water Flow on the Stability of Geosynthetic-Soil Layered Systems on Slopes

This paper presents an analysis of the stability of geosynthetic-soil layered systems constructed on slopes when water is flowing along the slope. Equations are presented for the factor of safety of infinite slopes as well as slopes of finite height. In the case of an infinite slope, only the interface shear strength along the slip surface contributes to the stability. In the case of a slope of finite height, the contributions of the buttressing at the toe of the slope and of geosynthetic tension are taken into account, in addition to interface shear strength. The analysis shows that the influence of water flowon the stability of a geosynthetic-soil layered system can be very significant if the slip surface is above the geomembrane. In this case, the factor of safety of a layered system with water flow can be as low as one half of the factor of safety without water flow. The analysis shows that the influence of water is small, and in some cases negligible or even zero, if the slip surface is below the geomembrane.

Breeding ecology, nest characteristics, and nest-site selection of stream- and lake-dwelling rock bass, Ambloplites rupestris (Rafinesque)

This study examines the breeding ecology, nests, and nest-site selection of stream-dwelling rock bass, Ambloplites rupestris (Rafinesque), populating the Middle Thames River near London, Ontario. Breeding in this stream began earlier, at lower temperatures, and continued longer than in other documented lake-breeding populations. These responses were related to flooding which repeatedly thwarted breeding attempts. Nesting and spawning continued asynchronously throughout the seasons, increasing breeding opportunities. Older, larger males spawned earliest in the season, allowing them increased renesting opportunities. The duration of each stage in nesting and brood development was documented. Nests were generally larger than those of other rock bass populations. Male size and nest size were positively related. Nests were elliptical rather than circular as in lakes, reflecting the influence of water flow. Males demonstrated nest-site selection: individual nest sites were allocated nonrandomly with respect to depth, reflecting the availability of appropriate nesting substrates, and the majority of nests were constructed downstream from obstructions to current. Many of these features of rock bass reproduction can be interpreted as being responses to the relatively variable and rigorous environment of the stream habitat as compared with lakes.

The Influence of Waterflow on Brown Trout Parasites

The Influence of Waterflow on Brown Trout Parasites