Changes of atmospheric water vapor budget in the Pearl River basin and possible implications for hydrological cycle
Changes of atmospheric water vapor budget in the Pearl River basin and possible implications for hydrological cycle
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DOI：
10.1007/s00704-010-0257-z
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发表时间：
2010-02
影响因子：
3.4
通讯作者：
Qiang Zhang;Chong-yu Xu;Zeng-xin Zhang;Y. Chen
中科院分区：
文献类型：
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作者：
Qiang Zhang;Chong-yu Xu;Zeng-xin Zhang;Y. Chen
利用NCAR/NCEP再分析资料，采用连续小波变换和简单两阶段线性回归技术，对珠江流域四边缘水汽通量和水汽收支的突变性、趋势性和周期性特征进行了深入分析。文中还讨论了这些变化对水文循环和水资源管理的可能影响。结果表明：（1）通过珠江流域四个边缘的水汽输送量都在减少，特别是从研究流域北部边缘出去的水汽输送量的变化更为明显。（2）小波变换谱表明，自80年代初以来，北边缘水汽通量的月变化趋势是减少的，这种减少主要体现在小波功率谱的间歇性分布上。通过北部边缘的水汽通量的周期性特征表明，20世纪80年代以后，水汽通量向北的传播减弱;（3）水汽通量与降水和径流的密切关系表明，20世纪60年代初期以后，珠江流域水文循环的改变主要表现为水汽通量的季节性变化。这些水汽通量变化的直接后果之一是珠江流域干湿状况的季节转换。不同流域的水文循环对气候变化的响应可能不同。珠江流域对全球气候变暖的水文响应主要表现为降水变化的季节性变化：冬季变湿，夏季变干。珠江流域降水季节转换规律的发现，对气候变化特别是全球变暖背景下珠江流域水资源管理具有重要的科学意义和实用价值。
In this study, we thoroughly analyzed abrupt behaviors, trends, and periodicity properties of water vapor flux and moisture budget entering and exiting the four edges of the Pearl River basin based on the NCAR/NCEP reanalysis dataset by using the continuous wavelet transform and the simple two-phase linear regression technique. Possible implications for hydrological cycle and water resource management of these changes are also discussed. The results indicate that: (1) the water vapor propagating through the four edges of the Pearl River basin is decreasing, and it is particularly true for the changes of the water vapor flux exiting from the north edge of the study river basin. The transition point from increase to decrease occurs in the early 1960s; (2) The wavelet transform spectra indicate that the monthly water vapor flux through the north edge decreases and this decrease is mainly reflected by intermittent distribution of the wavelet power spectra after early 1980s. The periodicity properties of the water vapor flux through the north edge imply that the northward propagation of water vapor flux decreases after the 1980s; (3) close relations between water vapor flux, precipitation and streamflow implies that the altered hydrological cycle in the Pearl River basin is mainly manifested by seasonal shifts of water vapor flux after early 1960s. One of the direct consequences of these changes of water vapor flux is the seasonal transition of wet and dry conditions across the Pearl River basin. Regional responses of hydrological cycle to climate variation/change could be different from one river basin to another. Hydrological responses of the Pearl River basin to the global warming are mainly demonstrated by seasonal shifts of precipitation changes: winter comes to be wetter and summer tends to be dryer. The finding of the seasonal transition of precipitation in the Pearl River basin is of great scientific and practical merits in basin scale water resource management in the Pearl River basin under the changing climate and global warming in particular.