摘要:采用气候趋势倾向率、小波变换、Mann-Kendall突变检验等方法，对黄土高原砚瓦川流域1951—2009年近60年的降水进行时空特征分析。结果表明：从时间过程上看，该流域春、秋季降水量明显趋于减少，而夏、冬季则稍有增加，年降水量在波动中呈下降趋势；年降水量最显著的振荡周期为32年，经历高-低-高3个循环交替，夏、秋季的周期变化对年降水量的影响较大；该流域50年一遇的年降水量和最大日降水量分别是815.3 mm和111.5 mm；降水年内分布主要集中在6—9月，占全年的68%。年降水量没有明显的突变现象，但在50年代有两次降水转折，80年代后期以来出现七次降水转折。从空间分布上看，流域年降水呈西高、东低的态势，其中东北部年降水量近60年来下降幅度较大，西部年降水量下降幅度较小。

关键词:降水  时空变化  砚瓦川流域  黄土高塬沟壑区

AbstractSpatiotemporal variation characteristics of precipitation in nearly 60 years from 1951 to 2009 were analyzed for the Yanwachuan watershed of the Loess Plateau by the climate tendency rate, wavelet and Mann-Kendall abrupt change test analysis method. Temporally, annual precipitation over th e watershed presented a declined trend in a fluctuating way, with precipitation in spring and autumn tending to decrease obviously and precipitation in summer and winter increasing slowly. Annual precipitation had a significant oscillation period of 32 years and three alternative cycles of highlowhigh precipitation. Periodic change in summer and autumn influenced annual precipitation more remarkably. Annual precipitation and the maximum daily precipitation with 50year return period for the watershed were 815.3 and 111.5 mm, respectively. Precipitation in a year mostly occurred from June to September, and the proportion is 68%. Annual precipitation did not show an obviously abrupt change, but two transitions in precipitation were observed in the 1950s and seven transitions in the late 1980s. Spatially, annual precipitation over the watershed during the 60 years showed the distribution that was high in the west and low in the east, of which annual precipitation in the northeast declined more than that in the west.

Key wordsprecipitation  spatiotemporal variation  Yanwachuan watershed  gully area of the Loess Plateau

文章编号： 0258_7106 (2016) 01_0018_15 中图分类号： P618.41 文献标志码：A

改回日期：2015_07_11

基金项目

**通讯作者耿新霞， 女， 1979年生， 助理研究员， 成矿规律研究方向。 Email： gen gxinxia@cags.ac.cn