riprap

Riprap causes morphological changes in the riverbeds they surround. One such change is the reduction of sediment settlement in the river channel, which can lead to scouring of the river bed as well as coarser sediment particles. This can be combatted by increasing the distance between the pieces of riprap and using a variety of sizes.{{Cite journal |last=Qi |display-authors=etal |date=June 2021 |title=Scour at pile groups and effects of riprap gradation and thickness on the scour reduction |url=https://www.researchgate.net/publication/352680621 |journal=Journal of Hydraulic Engineering |volume=52 |issue=6 |via=ResearchGate}}

The usage of riprap may not even stop erosion, but simply move it downstream.{{Cite journal|last1=Reid|first1=David|last2=Church|first2=Michael|date=2015|title=Geomorphic and Ecological Consequences of Riprap Placement in River Systems|url=http://doi.wiley.com/10.1111/jawr.12279|journal=JAWRA Journal of the American Water Resources Association|language=en|volume=51|issue=4|pages=1043–1059|doi=10.1111/jawr.12279|bibcode=2015JAWRA..51.1043R|s2cid=129730847 }} Additionally, the soil beneath the riprap can be eroded if the rock was just placed on top without any buffer between the layers such as a geotextile fabric or smaller riprap (crushed stone).{{Cite journal |last=Sfeir |display-authors=etal |date=August 2021 |title=RIPRAP FILTERS AND STABILITY OF RIPRAP COVERED SLOPES |url=https://www.researchgate.net/publication/356101606 |journal=Riprap for Scour Countermeasures |via=ResearchGate}}

Riprap affects the amount of organic material in a waterbody by acting as a filter, catching wood and leaves before they can enter the water. Riprap also covers and prevents plants from growing through, which can reduce shade over the water.

Introducing ripraps creates a rocky environment that can affect a waterbody's ecology by making the ecosystem more heterogeneous.{{Cite journal |last=Shields |display-authors=etal |date=June 1995 |title=Experiment in Stream Restoration |url=https://doi.org/10.1061/(ASCE)0733-9429(1995)121:6(494) |journal=Journal of Hydraulic Engineering |volume=121 |issue=6 |pages=494–502 |doi=10.1061/(ASCE)0733-9429(1995)121:6(494) |via=ASCE Library}} While it can negatively affect some organisms by removing shoreline vegetation, the rock can provide important refuge for invertebrates and small fish.{{Cite journal|last1=Chhor|first1=Auston D.|last2=Glassman|first2=Daniel M.|last3=Smol|first3=John P.|last4=Vermaire|first4=Jesse C.|last5=Cooke|first5=Steven J.|date=2020|title=Ecological consequences of shoreline armoring on littoral fish and benthic macroinvertebrate communities in an Eastern Ontario lake|url=http://link.springer.com/10.1007/s00027-020-00740-0|journal=Aquatic Sciences|language=en|volume=82|issue=4|pages=73|doi=10.1007/s00027-020-00740-0|bibcode=2020AqSci..82...73C |s2cid=220857360|issn=1015-1621}} By preventing woody plants from growing and shading the water, riprap can also increase the amount of algae and hydrophytes.{{Cite journal |last=Fischenich |first=J. Craig |date=April 2003 |title=Effects of Riprap on Riverine and Riparian Ecosystems |url=https://apps.dtic.mil/sti/pdfs/ADA414974.pdf |archive-url=https://web.archive.org/web/20220601074310/https://apps.dtic.mil/sti/pdfs/ADA414974.pdf |url-status=live |archive-date=June 1, 2022 |journal=Wetlands Regulatory Assistance Program |via=US Army Corps of Engineers}}

File:11-8-07 riprap photo.jpg|Concrete rubble used as riprap along the San Francisco Bay shoreline

File:Sea defences - geograph.org.uk - 775461.jpg|Modular concrete block riprap

File:Access to Beach is Blocked - geograph.org.uk - 1107949.jpg|Modular concrete block riprap

File:Cape Hinomisaki Izumo04bs3200.jpg|Modular concrete block riprap

File:Riprap.jpg|Riprap lining a lake shore

File:Construction of river channel closing structure in the Mississippi NRRA (7df8f79e-1761-4967-a358-64b4e9a4d1c3).jpg|Riprap closing off a channel on the Mississippi River

File:Corps completes Yolo Bypass levee repairs (6792076725).jpg|Riprap protecting a levee

File:Crews replacing riprap at Seawall.jpg|Crews replacing riprap at Galveston Seawall after a 1915 hurricane

File:Dawlish Warren , Rip Rap and Coastal Scenery - geograph.org.uk - 1345833.jpg|Riprap protecting a concrete retaining wall

• Dolos
• Debris
• Gabion Basket
• Rubble

{{Reflist}}

• Ciria-CUR (2007) - [http://www.kennisbank-waterbouw.nl/DesignCodes/rockmanual/introduction.pdf Rock Manual - The use of rock in hydraulic engineering].
• N.W.H. Allsop (2002) - [https://books.google.com/books?id=0XtfQ_iW0_YC&dq=%22rock+manual%22&pg=PP1 Breakwaters, coastal structures and coastlines].
• US Dept. of Transportation (2004) - [https://web.archive.org/web/20040630002627/http://www.fhwa.dot.gov/environment/fspubs/00232839/page10a.htm Trail Construction and Maintenance Notebook ]

• [http://soilandwater.ohiodnr.gov/portals/soilwater/pdf/stream/stfs16.pdf Ohio Dept. of Natural Resources riprap guide]
• [https://www.usbr.gov/tsc/techreferences/hydraulics_lab/pubs/PAP/PAP-0790.pdf US Bureau of Reclamation publication on riprap for dam overtopping]
• [http://www.dnr.state.mn.us/permits/water/answers.html#riprap Minnesota DNR]
• [http://minerals.usgs.gov/minerals/pubs/commodity/stone_crushed/cstonmyb05.pdf USGS Minerals Yearbook: Stone, Crushed]

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Category:Building stone

Category:Types of wall

Category:Earthworks (engineering)

Category:Coastal construction