Erosion, deposition

These materials can damage equipment by means of corrosion, erosion, deposits, plugging, catalyst poisoning, etc. 

The following chapter is a case study of how the three problem areas illustrated (dissolved oxygen depletion, erosion/deposition, and potentially toxic trace elements) may be successfully addressed on a major river system using quantitative, semi-quantitative and qualitative approaches respectively. 

The goals of this chapter do not include a "state of the art" literature review which would be appropriate for a more in-depth discussion of one particular problem area. Rather the intent is to illustrate mechanistic approaches to river quality assessment using the three globally relevant water quality problem areas discussed in the previous chapter dissolved oxygen depletion, erosion/deposition, and potentially toxic trace elements. The information provided does not include all rationale, methology or approaches used in the study as this is beyond the scope of the chapter. Additional general information on application of the intensive river quality assessment approach in the Willamette River basin may be found elsewhere (4-9, 11-14, 17). 

Erosion/Deposition Impact Matrix and Map. Methods applied in this semi-quantitative assessment involved mapping depositional features using high and low altitude imagery, numerical ranking of land use activity impacts and construction of problem matrixes. The information generated in these first steps were applied to the Universal Soil Loss Equation (15-16),... 

Results. Using the information generated in the analysis, an erosion/deposition impact matrix was developed as shown in Table 3 (14,15). The horizontal axis... 

Fig. 1.9. ERO code simulation of carbon and beryllium erosion and transport inside the divertor of JET showing the multi-step transport of C in contrast to the one step erosion-deposition of Be...

Fig. 9.6. Dependence of the erosion/deposition balance on plasma temperature Te and the carbon concentration in the edge plasma in at %...

The quantification of the co-deposition rate in ITER is still subject to large uncertainties and analysis carried out to date provide only general trends rather than accurate predictions. This subject is thoroughly discussed in several publications (see for example [97]). The main uncertainties arise primarily from the plasma edge physics parameters, which are anticipated to strongly affect the erosion, deposition and co-deposition patterns and rates, from uncertainties of the chemical erosion yields at high fluxes [33] and from the effect of temperature and H-atomic flux on deposition patterns and rates in areas hidden from the plasma. 

Modeling of Erosion, Deposition and Impurity Transport with the ERO-TEXTOR Code... 

Genetically, the Aralian coasts may be classified into three types, namely, abrasion coasts (modeled by marine erosion), depositional and abrasion-deposition-al ones [25]. Coasts of the first type (abrasion) are most common at the western, northern and part of the southern margins of the sea. They are built of compact calcareous marls and sandy-clayey Paleogene and Neogene rocks. Typically, they form high (up to 200 m) abrasion cliffs with wave-cut notches and a narrow strip of sandy beach. In areas where loose rocks occur, coasts are rather low, with a shallow notch and broader beach. There exist varieties of abrasion coasts, such as abrasion-denudation ones and abrasion coasts with slumps, with material from screes, rockfalls, and slumps present in the nearshore zone in abundance. 

Stanley, D.J., and Wear, G.M. 1978. The "mud-line" An erosion-deposition boundary on the upper continental slope. Marine Geology, 28 M19-M29. 

According to Stauffer (1973) the Quaternary cover is found on coastal lowlands and constitutes the floors of some inland valleys. It also finds localized expression on terraces or as remnants of erosion deposits at higher levels. 

Erosion/deposition processes (short term seconds to days)... 

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