嘉陵江汇流特性统计及分形分析

嘉陵江汇流特性对长江重庆河段的泥沙运动与河床演变影响重大。根据1955~2011年的原型实测水文资料，通过数理统计方法，分析了嘉陵江汇流比的变化趋势和频率分布特性，应用分形几何方法研究了日汇流过程曲线特征，提出采用分形汇流比RD全面量化复杂汇流过程，并探讨了RD的参数构成及变化规律。结果表明：嘉陵江日汇流比R的变幅随北碚站流量Q的增加而逐渐缩窄；各级流量对应的汇流比区间频率具有中间大、两端小的分布特性，累积频率分布曲线呈现两端平缓、中间陡峻的变化特点；分形汇流比RD随流量的增大而增大，全年RD与汛期RD的变化规律基本一致，汛期汇流过程对全年汇流特征影响显著。

Study of confluence characteristics of Jialing River Basin based on statistic and fractal analysis

The confluence characteristics of runoff at Jialing River estuary is important to the sediment transport and river bed evolution of Chongqing reaches of Yangtze River. Based on the observed hydrological data from 1955 to 2011, the variation trend and frequency distribution characteristics of the confluence ratio of Jialing River are analyzed by using the mathematical statistics method, and the continuous daily confluence process curves are studied by using the fractal geometry method; the comprehensive quantification of the complex confluence process is obtained by the fractal confluence ratio R_D , and the expression and variety law of R_D are discussed. The results show that: with the increase of the flow (Q) at Beibei Hydrological Station, the variation amplitude of daily confluence ratio R gradually becomes small; the distribution curve of the interval frequency of confluence ratio under the flow at all levels is higer in the middle and lower at two ends, and the cumulative frequency curve is gentle at the both ends and steep in the middle; with the increase of flow, R_D increases, the variation of annual R_D and flood season R_D is generally consistent, and the confluence process in flood season influences the annual confluence characteristics markedly.