Abstract:Studying the runoff and sediment characteristics and trends of sandy rivers in arid and semi-arid regions is of great significance for water and sediment regulation and prediction in the basin. Based on the macro (micro) perspective, the characteristics and trends of sandy rivers in arid and semi-arid areas were studied in detail, in order to provide theoretical help for flow and sediment regulation and prediction in river basins. In this study, the umulative distance method, ITA method and ITA-CB method were used to calculate the inflow flow and sediment transport rate of Kezier Reservoir, meanwhile the characteristics and trends of flow and sediment transport rate were systematically analyzed from the three scales of intrayear, interannual and interdecade scales. The results showed that:(1) The distribution characteristics of flow and sediment were highly similar in the year, with the highest value in July and the lowest value in March and January, respectively, with strong volatility and obvious differences on the interannual scale. (2) The annual inbound flow in the past 58 years showed an upward trend with an increasing tendency, and in summer it showed an upward trend with a weakening tendency, among which the upward trend of the high-value area weakened, and it was necessary to pay attention to the extreme climate of drought. (3) The annual sediment transport rate showed an upward trend, and the trend characteristics under the quarterly scale showed a downward trend, among which the downward trend in summer and autumn tended to weaken, and it showed a tendency to strengthen in winter. Compared with traditional analysis methods, ITA and ITA-CB methods could effectively identify the microscopic trends within the sequence, and were more helpful for analyzing the changes of regional flow and sediment in detail.