PREDICTION METHOD OF SAND-MOVEMENT DIRECTION IN RIVERS BY GEOCHEMICALELEMENTS

The analysis of sand samples by X-ray fluorescent spectroscopy (XRF) g ives the ratio of the geochemical elements to construct the sand sampl es. The application of the ratio matching to sand samples represents t he correlation number between two sand samples with respect to geochem ical elements. When the correlation number between two sand samples is low, the two samples are not geochemically similar each other. This d enotes that the exchange of sand between two sampling points is scarce or the two samples are independent. When the correlation number betwe en two sand samples is high, the two samples are geochemically similar , signifying that the exchange of sand between two sampling points is frequent or there is sand movement between two sampling points. If the re exists prominent sand movement in the study area, the correlation n umber is almost 1 and kilo count number per second of each geochemical element per weight decreases along the flow direction. The decrease i s caused by the reduction of sizes and the adherence of dirt on the su rface of sand particles. Since the flow direction in rivers is usually the same as the direction of sand movement, it can be verified. This study obtains satisfactory results applying the method of prediction i n sand movement to sediments in rivers.