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Selection of Parameters to be Monitored
Published in Larry W. Canter, River Water Quality Monitoring, 1985
Stream flow can be estimated from precipitation data, but it is much better to use information based on actual stream flow measurements. Stream flow measurements include measurements of stream discharges as well as water surface elevations, with the collection of stream flow data being called stream-gaging (Butler, 1957). Most stream-gaging discharge measurements are made by the area-velocity method using a current meter to measure the velocity. In the area-velocity method the channel cross section is divided into subareas, each subarea is multiplied by its mean sub-areal velocity to determine the subareal discharge, and the sub-areal discharges are added to determine total stream discharge. The mean velocity is computed by dividing the total discharge by the total cross sectional area. Field data for an area-velocity discharge measurement consists of measurements of velocity, depth, and width-stationing at various positions in the channel cross section.
The Cooper–Eromanga petroleum province, Australia
Published in Australian Journal of Earth Sciences, 2022
D. Kulikowski, K. Amrouch, K. Pokalai, S. I. Mackie, M. E. Gray, H. B. Burgin
High-velocity cemented calcite zones are present within the Eromanga Basin and can distort the true subsurface image when not incorporated into velocity models (Kulikowski, 2017; Kulikowski, Hochwald, et al., 2016). Precise interval-velocity modelling can include these high-velocity zones for more accurate seismic depth conversion that consider areal velocity changes. Interval velocity models are also used when anomalous velocities are present within a specific stratal unit, which can be caused by overpressures, cementation or the presence of faults and fractures. To capture these areal velocity changes, 3D velocity modelling is recommended.
Student understanding of approximations in physics
Published in International Journal of Mathematical Education in Science and Technology, 2023
K. K. Mashood, Arvind Kumar, Anwesh Mazumdar
This is precisely the notion tested in Q. 3 (Figures 13) and Q. 13 14). The contexts are very different, but the underlying idea is common. Q. 3 deals with the continuity equation of a liquid. Q. 13 deals with the relation between angular momentum and areal velocity for a planar orbit.