Scour Parameters Research Articles

Practical simulation of sediment transport in urban runoff

A model for simulating sediment transport in urban areas has been developed based on the concept of "equivalent solids reservoirs." The processes of erosion, deposition, and routing have been represented by simple algorithms, which are applied to typical urban drainage elements (surfaces, gutters, pipes, and detention ponds). Input requirements are limited and include two sediment characteristics (particle size and relative density), scour and deposition parameters, and initial sediment loadings. Hydraulic properties of the drainage elements and the inflow hydrograph to each element are also required. This sediment transport submodel is an integral part of Q'URM, the Queen's University Urban Runoff Model. It has been developed and calibrated on the basis of data from a stormwater quality sampling program on the Calvin Park basin in Kingston, Ontario, and verified on the basis of data from an independent study of runoff quality in the Malvern basin in Burlington, Ontario. Key words: urban hydrology, sediment transport, simulation, measurement.

On the spatial frequency of linear ice scours on the seabed

In this paper the factors which affect the spatial frequency of linear scours on the seabed are identified through the use of a Monte Carlo simulation model. This identification is followed by analysis leading to various formulas useful for assessing the risk to undesea structures from scouring ice. Specifically, formulas for the conditional probability that a scour will intersect a segment of pipeline or an installation in the shape of a convex geometric figure, expressed in terms of measured scour parameters, are developed. In addition, formulas for the annual probability that a segment of pipeline may be scoured and the expected number of pipeline/scour interactions are obtained. Similarly, it is shown how to calculate the annual probability that a rectangular region will be scoured. Definitions of areal and scour start-point density are presented which precisely delineate the important concepts associated with scour frequency as seen in existing sonogram imagery. The use of these concepts is illustrated by their application to some simulated sonogram imagery. Finally, the methods are applied to recent resurvey results for an area on the northern Grand Banks of Newfoundland to estimate an upper bound on the annual scour rate for the region.