摘要
本文首先应用Mann-Kendall非参数检验方法对白洋淀流域7个气象站1957年～2006年50年平均气温、降水量序列的长期变化趋势进行分析,并进行显著性检验。针对Mann-Kendall非参数检验方法的不足,在此方法的基础上运用R/S分析方法,估算各时间序列的Hurst指数,得到流域气温、降水量的持续性特征,并采用随机重排法对估算结果进行稳定性检验,再结合两种方法得到其未来变化趋势及其持续性。研究结果表明:流域内平均气温具有明显的上升趋势,其中冬季气温贡献最大,且未来一段时间气温将呈持续上升趋势;降水量总体上呈现较为明显的下降趋势,其中夏季降水量的下降趋势最为明显,未来一段时间降水量可能持续下降。白洋淀流域未来气候将向干热化方向发展,这可能是白洋淀"干淀"的一个重要原因。
In this study, long-term trends in the time series of air temperature and precipitation from 1957 to 2006 were detected by using nonparametric Mann-Kendall method in the Baiyangdian basin. The non-parametric Mann-Kendall test, which is recommended by World Meteorological Organization （WMO）, is widely used for analyzing the trends of environmental time series, such as stream flow, temperature and precipitation. R/S method was also applied to generalize the Hurst exponent, in order to estimate long-range dependence of air temperature and precipitation. It is a non-parametric method and shows great stability. Then, the reliability of the estimated results for Hurst exponent was tested by comparing H values, which were calculated by both original time series and the stochastically reset ones, respectively. Finally, future trend characteristics of air temperature and precipitation were analyzed by combining R/S with Mann-Kendall. The future trend is not only an important factor in explaining why the rivers and lake dried up but also of great significance to hydrological cycle and water resources management in the Baiyangdian basin. The results show that air temperature in the Baiyangdian basin demonstrates an obvious increasing trend in the past and future. The mean increasing amplitude of air temperature is up to 1.9℃ in the past 50 years, to which winter temperature has the greatest contribution, and annual mean temperature would continue to ascend. On the other hand, the trend of precipitation is not as significant as that of air temperature. Generally, precipitation shows a descending trend, especially in summer, and there is a tendency of even less precipitation in the future. The mean decreasing amplitude of annual precipitation is up to 131.3mm in the past 50 years and the greatest decrease is in summer. The differences of β and H values between air temperature and precipitation in space show that air temperature and precipitation are not absolute consistent with variation （i.e., an ascending temperature may lead to increase or decrease in precipitation）. In other words, temperature increase doesn＇t directly affect precipitation. It is concluded that the climate in the Baiyangdian basin can become warmer and drier in the future, which is the major cause of drying up of the Baiyangdian Lake.
出处
《资源科学》
CSSCI
CSCD
北大核心
2009年第9期1498-1505,共8页
Resources Science
基金
北京师范大学"京师学者"特聘教授启动经费
科技部国际合作项目(编号:2006DFA21890)资助
关键词
白洋淀
气温
降水
未来趋势
非参数检验
HURST指数
Baiyangdian Lake
Air temperature
Precipitation
Long-term trend
Nonparametric statistical test
Hurst exponent
