Efficient sampling for estimating suspended sediment loads - case studies from the river Rhine and the river Elbe

摘要

The main deficiency of most long-term sampling programmes is that they mostly are not well adapted to processes showing high variability, as they do not take account of the statistical character of the process observed. Therefore, a great number of unnecessary samples are often taken. To obtain load estimates within an acceptable range of accuracy and precision sampling strategies have to be applied. This paper describes the concept of stratified sampling and presents results of case studies from the rivers Rhine and Elbe with regard to the estimation of yearly sediment loads. From the simulations the conclusion can be drawn that the sampling rate in both rivers can be reduced significantly in comparison to daily sampling if a statistically based strategy is applied and the sampling scheme is well adjusted to the nature of the process by means of historical data.