阿克苏河源流区径流量与降水量丰枯变化和相关性研究

利用新疆塔里木河流域阿克苏河源流区出山口沙里桂兰克和协合拉两水文站1957-2008年近50a的径流和降水数据, 借助Z指数法、参数T检验和非参数检验和小波变换等, 分析了阿克苏河两水文站降水量和径流量的变化趋势, 以及二者多时间尺度相关关系.结果表明:近50a来, 沙里桂兰克、协合拉径流量和降水量均呈增加趋势, 两水文站径流量在1993年发生了显著的增多突变, 其中, 降水量突变点沙里桂兰克在1985年, 协合拉在1986年.沙里桂兰克和协合拉降水量和径流量丰枯指数由突变前的"偏枯"和"正常"等级为主转变为突变后的"正常"和"偏涝"等级占优势.沙里桂兰克和协合拉径流量变化分别存在7a和6a的主周期, 降水量变化分别存在7a和4a的主周期.沙里桂兰克径流量和降水量在整个时间尺度上以正相关为主, 协合拉则以负相关为主, 在大于20a的时间尺度上两水文站径流量和降水量均呈不显著的正相关关系.

Research on the High-Low Flow Variation and the Correlation Between Runoff and Precipitation at the Headwaters of the Aksu River

Based on the past 50-a runoff and precipitation data at Shaliguilanke and Xiehela Hydrological Stations in the Aksu River, variation trend and correlation in various time scales between precipitation and runoff from the above two stations were analyzed by using the Z index method, t-test, non-parametric test and wavelet transform. It is found that: 1) the runoff and precipitation at the two hydrological stations had an increasing trend. Runoff increased abruptly at the two stations in 1993, whereas abrupt change point of precipitation occurred in 1985 at Shaliguilanke Station and in 1986 at Xiehela Station; 2) the high-low flow index of runoff and precipitation at the two stations changed from dry and normal grades before the abrupt change point to normal and flooded grades after the abrupt change point; 3) the main period of runoff variation at the two stations was 7 a and 6 a, respectively, and that of precipitation variation was 7 a and 4 a, respectively; 4) runoff and precipitation had positive correlation mainly at Shaliguilanke Hydrological Station and negative correlation at Xiehela Hydrological Station. However, runoff and precipitation presented non-significant positive correlation at two hydrological stations in the period longer than 20 a.