Flood hydrology and geomorphic effectiveness in the central Appalachians

Earth Surface Processes and Landforms - Tập 15 Số 2 - Trang 119-134 - 1990
Andrew J. Miller1
1Department of Geography, University of Maryland Baltimore County, Baltimore, Maryland 21228

Tóm tắt

AbstractThis paper compares hydrologic records and geomorphic effects of several historic floods in the central Appalachian region of the eastern United States. The most recent of these, occurring in November 1985, was the largest ever recorded in West Virginia, with peak discharges exceeding the estimated 500‐year discharge at eight of eleven stations in the South Branch Potomac River and Cheat River basins. Geomorphic effects on valley floors included some of the most severe and widespread floodplain erosion ever documented and exceeded anything seen in previous floods, even though comparable or greater rainfall and unit discharge have been observed several times in the region over the past 50 years. Comparison of discharge‐drainage area plots suggests that the intensity and spatial scale of the November 1985 flood were optimal for erosion of valley floors along the three forks of the South Branch Potomac River. However, when a larger geographic area is considered, rainfall totals and discharge‐drainage area relationships are insufficient predictors of geomorphic effectiveness for valley floors at drainage areas of 250 to 2500 km2.Unit stream power was calculated for the largest recorded flood discharge at 46 stations in the central Appalachians. Maximum values of unit stream power are developed in bedrock canyons, where the boundaries are resistant to erosion and the flow cross‐section cannot adjust its width to accommodate extreme discharges. The largest value was 2570 W m−2; record discharge at most stations was associated with unit stream power values less than 300 W m−2, but more stations exceeded this value in the November 1985 flood than in the other floods that were analysed. Unit stream power at indirect discharge measurement sites near areas experiencing severe erosion in this and other central Appalachian floods generally exceeded 300 W m−2; reach‐average values of 200‐500 W m−2 were calculated for valleys where erosion damage was most widespread. Despite these general trends, unit stream power is not a reliable predictor of geomorphic change for individual sites. Improved understanding of flood impacts will require more detailed investigation of interactions between local site characteristics and patterns of flood flow over the valley floor.

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Tài liệu tham khảo

10.2307/621860

Bailey J. F., 1975, Hurricane Agnes rainfall and floods, June‐July 1972’, U.S. Geological Survey Professional Paper, 924, 403

10.1130/0016-7606(1977)88<1057:SRTFWE>2.0.CO;2

Baker V. R., 1984, Sedimentology of Gravels and Conglomerates, 87

Baker V. R., 1987, Catastrophic Flooding, 1

10.1130/0016-7606(1987)98<635:FGOTKG>2.0.CO;2

10.2307/622210

Burkham D. E., 1972, Channel changes of the Gila River, Safford Valley, Arizona, 1846‐1970, U.S. Geological Survey Professional Paper, 655, 24

Calvel J., 1987, Geomorphological effects of the Segre flood of November 8th, 1982 in Catalonia. Spain, Studia Geomorphologica Carpatho‐Balcanica, 21, 109

Camp J. D.andMiller E. M.1970. ‘Flood of August 1969 in Virginia’ U.S. Geological Survey Open‐File Report unnumbered.

Clark G. M., 1987, Catastrophic Flooding, 355

10.1029/WR010i001p00106

10.1130/0091-7613(1978)6<617:CBTFGE>2.0.CO;2

10.1016/0022-1694(87)90146-6

Eisenlohr W. S., 1952, Floods of July 18,1942 in North‐central Pennsylvania, U.S. Geological Survey Water‐Supply Paper, 1134, 100

10.1139/e77-197

Grover N. C., 1937, The floods of March 1936: Part 3. Potomac, James, and Upper Ohio Rivers, U.S. Geological Water‐Supply Paper, 800, 351

Gupta A.1983. ‘High‐magnitude floods and stream channel response’ in Collinson J. D. and Lewin J. (Eds) Modern and Ancient Fluvial Systems. Special Publication of the International Association of Sedimentologists 6 219–227.

Gupta A., 1988, Flood Geomorphology, 301

10.1029/WR010i003p00499

Hack J. T., 1960, Geomorphology and forest ecology of a mountain region in the Central Appalachians, U.S. 0. Geological Survey Professional Paper, 347, 66

10.1139/e88-105

Hoxit L. R., 1982, Johnstown‐Western Pennsylvania storm and floods of July 19‐20, 1977, U.S. Geological Survey Professional Paper, 1211, 68

Interagency Advisory Committee on Water Data1982. ‘Guidelines for determining flood flow frequency’ Hydrology Subcommittee Bulletin17B U.S. Geological Survey Office of Water Data Coordination Reston Virginia.

Jacobson R. B. Cron E. D.andMcGeehin J. P.1989a. ‘Slope movements triggered by heavy rainfall November 3‐5 1985 in Virginia and West Virginia’ in Schultz A. P. and Jibson R. W. (Eds) Landslides of Eastern North America. Geological Society of America Special Paper 236 1–13.

10.1016/0169-555X(89)90015-9

Johnson R. A.1983. Stream channel response to extreme rainfall events: the Hurricane Camille storm in central Nelson County. Virginia unpublished Master's Thesis University of Virginia Charlottesville.

Kochel R. C., 1988, Flood Geomorphology, 169

10.1130/0091-7613(1987)15<718:ROTDIT>2.0.CO;2

Kresan P. L., 1988, Flood Geomorphology, 465

Leopold L. B., 1964, Fluvial Processes in Geomorphology, 522

Lescinsky J. B.1987. ‘Flood of November 1985 in West Virginia Pennsylvania Maryland and Virginia’ U.S. Geological Survey Open‐file Report 86–486.

Miller A. J.andParkinson D. J.in preparation. ‘Flood hydrology and geomorphic effects on river channels and flood plains: the flood of November 4‐5 1985 in the South Branch Potomac River Basin West Virginia’ in Jacobson R. B. (Ed.) Geomorphic Effects of the Storm and Flood of November3–5.1985 in the Central Appalachians. U.S. Geological Survey Bulletin.

10.1086/649652

Mussey O. D.1950. ‘Flood of June 1949 in Stokesville‐Bridgewater area’ Virginia Division of Water Resources Bulletin No.10 20pp.

10.1130/0016-7606(1986)97<1467:EOVAAC>2.0.CO;2

10.1080/00049188508702880

10.1002/esp.3760050102

Osterkamp W. R., 1987, Catastrophic Flooding, 201

Pomeroy J. S., 1980, Storm‐induced debris avalanching and related phenomena in the Johnstown area. Pennsylvania, with references to other studies in the Appalachians, U.S. Geological Survey Professional Paper, 1191, 24

Reneau S. L.andDietrich W. E.1987. ‘Size and location of colluvial landslides in a steep forested landscape’ in Beschta R. L. Blinn T. Grant G. E. Ice G. G. and Swanson F. J. Erosion and Sedimentation in the Pacific Rim Proceedings of the Corvallis Symposium August 1987: International Association of Hydrological Sciences Publication 165 39–48.

Ritter U. F., 1988, Flood Geomorphology, 243

Scatena F. N., 1986, Floodplain reconnaissance study, November 1985 flood, Potomac River Basin, Interstate Commission on the Potomac River Basin Technical Report, 86, 32

Schumm S. A., 1963, Channel widening and flood‐plain construction along Cimarron River in southwestern Kansas, U.S. Geological Survey Professional Paper, 352, 71

Shroba R. R., 1979, Storm and Hood of July 31‐August 1, 1976. in the Big Thompson River and Cache la Poudre River basins, Larimer and Weld Counties, Colorado, U.S. Geological Survey Professional Paper, 1115, 87

Stewart J. H., 1967, Erosion and deposition produced by the flood of December 1964 on Coffee Creek, Trinity County, California, U.S. Geological Survey Professional Paper, 422, 22

Stringfield V. T., 1956, The relation of geology to drainage, floods and landslides in the Petersburg area, West Virginia, West Virginia Geologic and Economic Survey Report of Investigations, 13, 19

Sullivan J. E.1983.Geomorphic effectiveness of a high‐magnitude rare flood in central Texas unpublished Master's Thesis University of Texas at Austin 214pp.

10.2307/279491

Webb R. H., 1987, Catastrophic Flooding, 247

Williams G. P., 1973, Erosional and depositional aspects of Hurricane Camille in Virginia, 1969, U.S. Geological Survey Professional Paper, 804, 80

10.1029/TR039i001p00001

10.1002/esp.3290030207

10.1086/626637

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Earth Surface Processes and Landforms

Tập 15 Số 2

119-134

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