Document: NUREG-0800
Document ID: 496b5bd8-c9a2-4cf6-a703-e41c51e155ec
Document Type: srp
Title: CHANNEL MIGRATION OR DIVERSION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1819/ML18190A201.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.9
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CFR Title: 

Content:
nts and the potential for future channel migration or diversion in the region. The phrase “channel diversions” is not commonly used in the literature, so the literature search should include other terms, such as “channel, stream, or river migration,” “channel, stream, or river meandering,” “channel, stream, or river geomorphology,” “physical hydrology,” and initiating events such as “landslides” and “levee breaks” or “breaches.” In any review of the literature, the potential for diversion, migration, or realignment of natural waterways should address the following locations relative to the reactor site: A. Upstream, and generally above-bank, due to geologic, seismic, or topographic changes, e.g., caused by hillslope failure or earthquakes. 6 The geologic doctrine of uniformitarianism essentially states that the nature and rates of geologic processes occurring now are the same as in the past. Thus, evidence of past channel migration can be inferred based on the identification of certain types of geomorphic features depicted on topographic (and geologic) maps. See Salisbury and Atwood (1908) for example. The same interpretive principles can be applied to the examination of aerial photographs and satellite imagery. See examples in Ray (1960). Catalogs of geomorphic images as observed from space are available on the following web sites: National Atmospheric Space Administration: https://visibleearth.nasa.gov/view_cat.php?categoryID=917, and the European Space Agency: https://earth.esa.int/web/guest/home. 7 Available online at http://geonames.usgs.gov/apex/f?p=262:1:0. 2.4.9-11 Draft Revision 4 – September 2018 B. Upstream (or downstream) and within the bank, and due to erosion, deposition or channel migration or diversion, e.g., loss of a revetment, or alluvial channel meander changes. C. Upstream (or downstream) and within the bank and due to climatic/ meteorological causes such as ice-jams. Evaluate the geographic layout of existing