Author(s): George Gergov; Tzviatka Karagiozova
Linked Author(s):
Keywords: Soil erosion; Suspended sediment load; Sediment yield; Partial sediment yield
Abstract: Abstract: The paper deals with measures of sediment load, which are rather scares and inaccurate. The information is being much required because of the ecological interest towards the river sediments, as they form river abiota and participate in the food chain of river biocenoses. The traditional measure and methods of study does not distinguish the contribution of a particular area in the total sediment load, neither the mapping. On the opposite, the new parameter–partial sediment yield MR (δ), which is introduced by the authors overcome some of the uncertainties in sediment load assessment. The partial sediment yield is the total annual suspended sediment load that has been formed on the catchment area between any two adjacent gauge stations. It is a presumption that sheet erosion develops uniformly over the watershed with close physical and geographic conditions. The space variability of the parameter might be mapped and a comparative studies with soil erosion should go. Once the partial sediment yield increases downstream, it means that the rate of soil erosion is high and new quantities of soil particles enter the river course because diverse sheet and rill erosion forms are being developed. Otherwise, when the yield value is negative, it means that river sediments lay down on the bed in discrete forms or on a thin layer over the riverbanks and terraces. From the other side, the results obtained could reveal inaccuracy of gauge measurements. The paper includes some statistical data for the country-side of Bulgarian rivers, the total sediment resource of the country and maps of the distribution of the partial sediment yield.
Year: 2004