Domestic wells in North America and elsewhere are typically constructed at relatively shallow depths and with the sand or gravel pack extending far above the intake screen of the well (shallow well seal). The source areas of these domestic wells and the effect of an extended gravel pack on the source area are typically unknown, and few resources exist for estimating these. In this article, we u...

6 [1] Gravel-bedded channels often become incised and degraded below dams. Gravel can 7 be added to the channel to rehabilitate hydrogeomorphic conditions, including those 8 promoting salmon spawning. When implemented without increasing bed slope, gravel 9 addition at downstream riffles back floods upstream riffles. A 2-year gravel augmentation 10 project was done to test the efficacy of a new ...

0003-682X/$ see front matter 2009 Elsevier Ltd. A doi:10.1016/j.apacoust.2009.07.003 * Corresponding author. Tel.: +1 217 352 6511. E-mail address: [email protected] (G.W. Swen Experiments were performed to measure the various sound-wave propagation parameters of two kinds of gravel, a crushed limestone and a stream-formed ‘‘pea gravel”, at frequencies between 25 and 200 Hz. The apparatus w...

Fairy Circles (FCs) are barren circular patches of soil surrounded by grass species, the origin of which is poorly understood. FCs feature in both the gravel plains and dune fields of the Namib Desert. While a substantial number of hypotheses to explain the origin and/or sustainability of fairy circles have been presented, none are completely consistent with either their properties or distribut...

Decisions about flood protection and river rehabilitation require prediction of the consequences of each possible management alternative. To provide such predictions, an integrative model is required that represents the cause-effect relations between revitalisation measures and morphologic, hydraulic and ecological consequences. This paper describes the hydraulics submodel of such an integrativ...

The 2003 flood of the Muda River reached 1,340 m3 /s at Ladang Victoria and adversely impacted 45,000 people in Malaysia. A flood control remediation plan proposed a levee height based on a 50-year discharge of 1 ,815 m3 /s obtained from hydrologic models. This design discharge falls outside the 95% confidence intervals of the flood frequency analysis based on field measurements. Instream sand ...

Submitted: Jul 12, 2013; Accepted: Aug 26, 2013; Published: Aug 29, 2013 Abstract: Sand production in water, oil and gas wells is usually controlled by gravel packing techniques worldwide. Consideration in the gravel pack design requires that the particle size is five or six times the formation sand depending on the formation sand median diameter. Sieve analysis result shows that the grain size...

UNLABELLED Fairy circles (FCs) are barren circular patches of soil surrounded by grass species. Their origin is poorly understood. FCs feature in both the gravel plains and the dune fields of the Namib Desert. While a substantial number of hypotheses to explain the origin and/or maintenance of fairy circles have been presented, none are completely consistent with either their properties or thei...

[1] The first extensive dataset on subaqueous bed material grain size in a large river subject to reduced sediment supply is investigated alongside bathymetry, modeled flow, and sediment flux. Results suggest that following sediment supply decline and a shift to a finer sediment supply, the gravel‐sand transition (GST) in fluvial systems extends and subsequently migrates upstream. The non‐abrup...