新疆精河流域河川径流及对气候变化的响应

根据精河流域1957—2012年的气温、降水和径流量等资料,分析了精河流域近55 a来径流量的变化趋势和周期特征,研究了河川径流及对气候变化的响应关系,并建立基于多变量时间序列自回归CAR(Controlled Auto-regressive)径流预测模型。结果表明:(1)精河径流在年内分配不均,季节变化明显,夏季集中,枯水期长且枯季径流量小。6—9月为径流连续最大4个月,占全年径流量的74%。(2)从20世纪80年代开始,河川径流量增加,持续至90年代,在21世纪有减小的趋势,1981—2005年平均年径流总量比1957—1980年增加了3.24%。(3)精河流域年径流量序列在21 a和13 a左右的振荡周期最为明显,其次是32 a和9 a,而其中的21 a和13 a时间尺度上的振荡是全时域的。(4)建立了径流与降水和气温的CAR模型,发现拟合平均相对误差为6.54%,均方根误差为0.039。用CAR模型模拟河流年径流量误差在可接受范围内,可以利用该模型对精河流域年径流量进行预测。

Hydrological Response of Runoff to Climate Change in Jinghe River Basin

Runoff formation is a complex hydro-climatic process influenced by temperature and precipitation. Based on hydrological and climatic data covering the period from 1957 to 2012, this paper presents a multi-variate time series controlled auto-regressive (CAR) model, to study the climate change and its effects on runoff of Jinghe River, Northwest China. The results showed that: The river runoff of Jinghe was distributed uneven and has obvious seasonal change around the year. It was concentrated on summer and has along dry season with less runoff. The monthly maximum river runoff was from June to September, which accounting for74% of annual runoff. The river runoff increased since the 1980s which continued to the 1990s, in the 21st century there was a trend of decreasing, The average annual runoff from 1981 to 2005 increased by 3.24% from 1957 to 1980.The oscillatory period of annual runoff series in Jinghe River Basin was 21a and 13a, and this period were more obvious, followed by 32a and 9a. The oscillation with a timescale of 21a and 13a was a full-time domain. The MRE is 6.54%, the MAE is 0.84×108m3, and the RMSE is 0.039. The CAR model passed the F-test and residual test, and the change trend of calculated and measured values of annual runoff is consistence, which means that the model was reasonable.