1955—2012年韩江入海径流量和输沙量多尺度变化特征

基于韩江流域 12个气象台站1955—2012年降水量、潮安站径流量和输沙量资料，采用Mann-Kendall非参数秩次检验及小波分析方法研究韩江流域入海径流量和输沙量的多尺度变化特征. 结果表明:1955—2012年韩江入海径流输沙量总体没有出现明显变化，1982年以来径流量未发生显著变化，但输沙量呈现显著减少；流域径流量、输沙量存在明显的25~30、9~14、3~8 a时间尺度变化周期，其中25~30 a震荡周期最为明显，具有全域性. 流域入海输沙量和径流量周期规律基本一致，但输沙量周期略滞后径流量周期；在4 a时间尺度上正负相交替频繁，变化剧烈，突变点较多，而12 a与30 a时间尺度正负相交替正常，表明短时间尺度受人类活动影响较大. 近年来修建大量水电站，森林草地覆被率的提高，以及用水量的增加是韩江流域近几十年来径流量和输沙量变化的主要因素.

Characteristics of Multi-Scale Variability of Water Discharge and Sediment Load in the Hanjiang River During 1955-2012

Based on daily precipitation, water discharge and sediment runoff recorded at 12 meteorological stations in the Hanjiang river and hydrological date gathered from Chaoan station from 1955—2012, the characteristics of multi-scale variations in flow discharge and sediment load are analyzed by Mann-Kendall trend test and wavelet analysis. The results indicate that there is no obvious variation in runoff and the sediment load from 1955-2012, a significant descendent trend in sediment load while the amount of runoff has no obvious variation during 1982-2012.There are three significant periodic variations at scales of 25~30a, 9~14a, 3~8a for runoff and sediment discharge, but the 25~30a scale is the most significant. The periodic of runoff and sediment discharge in Hanjiang river is consistent, but the periodic of sediment discharge slightly lags the periodic of runoff. At the 4-year scale, not only the positive and negative phases about the curves of runoff and sediment discharge have appeared frequently and sharply but there are so many mutation points, while at the 12-year and 30-year scales have appeared normally, human activity has a great power influence on short scales. Construction of a large number of hydropower stations, the improvement of forest vegetation coverage and an increase in water consumption are the main factors for the reduction of runoff and sediment yield in Hanjiang basin.