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Calibration Software Probability Density Function Tree rings and other calibration records Wiggle-Matching: Using fluctuations in calibration curve to obtain precise ages relatively-dated series.
More than 10,000 reservoirs have been constructed in agricultural watersheds in the United States since the 1940s to control floods and sediments.
Three sediment profiles were sampled at 5-cm intervals in a flood control reservoir in the Fort Cobb Reservoir Experimental Watershed in southwestern Oklahoma.
Radioactivity was measured with a γ spectrometer for radioisotopes 137Cs and 210Pb. Three models (constant flux-constant sedimentation [CFCS], constant initial concentration [CIC], and constant rate of supply [CRS]), which are widely used in the lacustrine and marine environments under slow-sedimentation conditions, were not applicable to fast-sedimentation conditions because of considerable 210Pbex input with the sediment, which is assumed negligible in the models.
The 137Cs tracer was conservative in the fraction of Data provided are for informational purposes only.
We collected 50 surface soil samples from overland in a watershed (15.6 km2), 28 subsoil samples from gully bank, and 43 sediment samples in channels. Proportion means were calculated by solving a linear mixing model.
ABSTRACT: Knowledge of sediment provenance is critical for precision conservation planning and calibration of soil erosion models.
The objectives are to evaluate the ability of 137Cs to apportion sediment source contributions, quantify uncertainty of the estimates, and estimate desirable sample numbers.
A modified CRS model that uses 137Cs age markers as references improved determination of the sediment chronology.
The average sedimentation rates were three to five times higher during the 1957 to 1963 time period than during the 1964 to 2011 period.
Reservoir sedimentation records provide a unique opportunity to retrospectively study the effects of land use changes and climate variations on sediment production if the sediment chronology could be properly determined.