水保所知识产出(1956---)知识库

There is an increasing demand for reliable methods to measure soil loss in order to get a
better understanding of sediment movement and to develop process-based sediment transport models.
This study described the design, calibration, and practical application of an instrumented technique that
automatically characterized surface flow in situ fields. The instrument consisted of a sampling assembly,
a measuring assembly, and a management platform. The special design combined with a volume-mass
conversion relationship was used to determine the exact volume and mass of the sediment-laden water,
thereby allowing the implementation of real-time measurement and synchronous calculation of runoff
rate and sediment concentration. Calibration results showed that normal distributions and an average
error of −3.67% were obtained for the target sediment concentrations of 2–1,000 g/L. Compared with the
gravimetric method, the average error of the new technique for sediment concentration was 4.82%, and
the highest precision was 98.50%. The high repeatability and accuracy of the technique suggest that it can
be used with confidence to give satisfactory results in fields. A field experiment under natural rainfall
showed that a grass-covered plot had 18.94% less runoff rate and 42.92% lower sediment concentration
than a bare soil plot, illustrating the impact of vegetation cover on reducing soil loss. This uniquely
designed instrument provides a new approach to real-time sediment detection in surface flow. It will be
beneficial for rigorously evaluating runoff and sedimentation and for in-depth research regarding water
and soil loss processes.