THE TENDENCY AND PREDICTION OF WATER AND SEDI-MENT AT THE MIDDLE REACHES OF THE HUANG HE RIVER
黄河中游区水,沙变化趋势及其预测

In this paper, the grey systematic analysis method is used to study and analyse the water and sediment data at the middle reaches of the Huanghe River. It was discovered that, for most station, the mean annual sediment runoff descends successively in three periods (1951?1970, 1971?979, and 1980?985). The reason for such variation was revealed, and the GM (2, 1) model was used for the prediction of periodical mean values of annual sediment runoff. The simulated value is agreement with measured value.