کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4576326 1629959 2013 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Trends in the suspended-sediment yields of coastal rivers of northern California, 1955–2010
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Trends in the suspended-sediment yields of coastal rivers of northern California, 1955–2010
چکیده انگلیسی

SummaryTime-dependencies of suspended-sediment discharge from six coastal watersheds of northern California – Smith River, Klamath River, Trinity River, Redwood Creek, Mad River, and Eel River – were evaluated using monitoring data from 1955 to 2010. Suspended-sediment concentrations revealed time-dependent hysteresis and multi-year trends. The multi-year trends had two primary patterns relative to river discharge: (i) increases in concentration resulting from both land clearing from logging and the flood of record during December 1964 (water year 1965), and (ii) continual decreases in concentration during the decades following this flood. Data from the Eel River revealed that changes in suspended-sediment concentrations occurred for all grain-size fractions, but were most pronounced for the sand fraction. Because of these changes, the use of bulk discharge-concentration relationships (i.e., “sediment rating curves”) without time-dependencies in these relationships resulted in substantial errors in sediment load estimates, including 2.5-fold over-prediction of Eel River sediment loads since 1979. We conclude that sediment discharge and sediment discharge relationships (such as sediment rating curves) from these coastal rivers have varied substantially with time in response to land use and climate. Thus, the use of historical river sediment data and sediment rating curves without considerations for time-dependent trends may result in significant errors in sediment yield estimates from the globally-important steep, small watersheds.


► Trends were found in suspended-sediment yield for all six watersheds.
► Increases in suspended-sediment yields occurred during 1964.
► Decreases in suspended-sediment yields occurred during the decades following 1964.
► These patterns resulted from land practices from logging and the flooding history.
► Trends show that the sediment rating curves have varied substantially with time.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hydrology - Volume 489, 10 May 2013, Pages 108–123
نویسندگان
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