ABSTRACT
This study focuses on the efficiency of a horizontal sampling bottle (Van Dorn), a low-cost instantaneous water sampler for rivers. Sand concentrations from five experiments on the Colorado River are compared with isokinetic US P-61-A1 (point-integrating) and US D-96-A1 (depth-integrating) measurements. Instantaneous point sampling is more uncertain compared to point- or depth-integrating sampling owing to the lack of time or spatial averaging and the non-isokinetic sampling design of instantaneous horizontal bottle sampler. However, theoretical sand-concentration profiles can be fitted to instantaneous point sampling to improve the estimation of near-bed concentration.
