vallée en toit perched river
Creator: | |
Language pair: | French to English |
Discipline: | Geography |
Definition / notes: | https://www.stblaisenp.co.uk/starr https://docplayer.fr/44563655-Cartographie-des-zones-inondab... (slide 28 of 43) Also, in the book \"River Mechanics\" https://books.google.co.uk/books?id=uOrdh7pOZ9wC&pg=PA289&lp... (page289) These all say that the river flow has brought sediment down during times of flood. The successive sediment deposits have built up at the banks to form levees. The water can overflow these in times of flooding and (as mentioned in your source text) can flood the surrounding floodplain areas. \'Perched channel\' seems to be used mainly for lava flows rather than water. \'Perched river bed\' seems to be used rarely and many references are from the same original source \'Perched river valley\' - I can only find one reference to at https://www.leg.mn.gov/docs/pre2003/other/800875.pdf . The reason for the term \'perched river\' is that the build up of sediment has created levees at the banks and caused the riverbed to rise. This results in the level of the river baseflow being higher (sometimes significantly higher) than the surrounding floodplain. As a result, when the river overflows or breaks the levees, there is rapid flooding of the rest of the valley and often dangerous, high velocity floodplain flows. For more reference and images, see the following - https://books.google.co.uk/books?id=c-h4AgAAQBAJ&pg=PA288&lpg=PA288&dq=%22perched+river%22&source=bl&ots=A8XKL8JIws&sig=ACfU3U1QXYfBw3Cz3wDk6h6SK47Q2og9sg&hl=en&sa=X&ved=2ahUKEwiGhY73xNjtAhWCnVwKHQNNB4A4UBDoATAIegQICRAC#v=onepage&q=%22perched%20river%22&f=false https://www.rms.nsw.gov.au/projects/01documents/blackadder-safety/blackadder-creek-flood-mitigation-assessment-report-2014-07.pdf https://www.gov.mb.ca/mit/wms/floodcontrol/arbasin/assiniboine.html (with pictures) https://cawaterlibrary.net/wp-content/uploads/2019/07/Appendix-I-Floodplain-Restoration-Opportunities-Analysis-FROA.pdf |
Your current localization setting
English
Select a language
Close search