| 摘要: |
| 【目的】研究黑河流域干旱指数的变化特征，为气候变化影响下该流域水资源的有效管理及农业发展提供依据。【方法】用参考作物蒸散量(ET0)与降水量(P)的比值表示干旱指数(AI)，根据黑河流域内12个气象站及流域外3个气象站近50多年的逐日气象资料，采用Penman-Monteith公式计算ET0，利用Mann-Kendall趋势检验法和ArcGIS插值研究P、ET0及AI的变化趋势和空间分布，基于Morlet小波函数分析AI序列的多时间尺度特征。【结果】近50多年来，黑河流域P、ET0和AI均呈现出明显的南北差异；流域内12个气象站中，大部分站点的P、ET0呈上升趋势，且上游野牛沟站、托勒站上升趋势显著；AI呈下降趋势，仅野牛沟站下降趋势显著，流域趋于湿润，上、中、下游季AI最大值分别出现在秋冬季、春冬季、冬春季；流域AI的多时间尺度变化主要存在19~23年、14~15年的中长振荡周期和7~10年、4~5年的短振荡周期，中长周期与太阳黑子活动的周期基本一致，短周期与大气环流和厄尔尼诺事件的周期基本一致。【结论】黑河流域多年来逐渐趋于湿润，其干湿变化存在明显的短周期和中长周期。 |
| 关键词: 黑河流域 干旱指数 多时间尺度 小波分析 |
| DOI： |
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| 基金项目:国家自然科学基金项目（91425302，51279166） |
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| Trends and multiple time scale characteristics of aridity index in Heihe river basin |
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ZHONG Feng,SU Xiaoling,GUO Jing
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| Abstract: |
| 【Objective】The trends of aridity index in Heihe river basin were investigated to provide basis for effective management of water resources and agricultural development. 【Method】The aridity index (AI) was calculated as the ratio of potential evapotranspiration (ET0) to precipitation (P).Daily ET0was estimated using the Penman-Monteith equation with the observed daily climate data for more than 50 years at 12 meteorological stations located in Heihe river basin and 3 stations out of it.The trends and spatial distribution of precipitation,ET0 and aridity index in different time scales were detected by Mann-Kendall test and interpolation tools in ArcGIS,and the Morlet wavelet analysis was used to analyze the multiple time scale characteristics of aridity index. 【Result】The annual precipitation,ET0 and aridity index of the north basin were different from those in south basin in recent 50 years.The average annual precipitation and ET0 at most of the 12 stations in the basin had increasing trends with time,and had significantly increasing trends at Yeniugou and Tuole stations in the upstream.Aridity index had decreasing trends,but only significant at Yeniugou station,indicating that the basin tended to be wetter.The upstream aridity index had peak values during autumn and winter,while midstream and downstream had peak values during spring and winter.Annual aridity index fluctuated with long cycles of 19-23 and 14-15 years and short cycles of 7-10 and 4-5 years.The long period was identical to sunspot cycle,while the short ones were basically same with the frequency of atmospheric circulation and El Nino events.【Conclusion】The study area was becoming wetter in recent years,and variations of annual aridity index presented short and long cycles. |
| Key words: Heihe river basin aridity index multiple time scale wavelet analysis |
