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Estimating sedimentation rates and sources in a partially urbanized catchment using caesium‐137
Author(s) -
Ormerod L. M.
Publication year - 1998
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/(sici)1099-1085(19980615)12:7<1009::aid-hyp643>3.0.co;2-i
Subject(s) - sedimentation , floodplain , hydrology (agriculture) , erosion , deposition (geology) , topsoil , sediment , environmental science , drainage basin , geology , channel (broadcasting) , soil science , geomorphology , soil water , geography , cartography , geotechnical engineering , engineering , electrical engineering
While there has been increased interest in determining sedimentation rates and sources in agricultural and forested catchments in recent years, there have been few studies dealing with urbanized catchments. A study of sedimentation rates and sources within channel and floodplain deposits of a partially urbanized catchment has been undertaken using the 137 Cs technique. Results for sedimentation rates showed no particular downstream pattern. This may be partially explained by underestimation of sedimentation rates at some sites by failure to sample the full 137 Cs profile, floodplain erosion and deliberate removal of sediment. Evidence of lateral increases in net sedimentation rates with distance from the channel may be explained by increased floodplain erosion at sites closer to the channel and floodplain formation by lateral deposition. Potential sediment sources for the catchment were considered to be forest topsoil, subsurface material and sediments derived from urban areas, which were found to be predominantly subsurface material. Tracing techniques showed an increase in subsurface material for downstream sites, confirming expectations that subsurface material would increase in the downstream direction in response to the direct and indirect effects of urbanization. © 1998 John Wiley & Sons, Ltd.