渭河流域近52年日照时数和风速时空变化特征

Variation characteristics of sunshine duration and wind speed in the last 52 years in Wei River Basin

利用渭河流域1959—2010年23个气象站的风速和日照时数观测数据,通过线性拟合、Mann-Kendall突变检验等方法分析了该地区近52 a日照时数和风速的年、季、月的时空变化以及突变特征。结果表明:近52 a来渭河流域大部分地区日照时数表现为减少趋势,平均每10 a减少10.13 h,1973年前后发生突变;空间分布上以关中平原减少最为突出,季节上以夏季和冬季的减少趋势最显著;流域年平均风速也呈明显减少趋势,平均每10 a减少0.05 m/s,1981年左右发生突变,4个季节的风速变化都是以关中平原和黄土高原丘陵沟壑区减少趋势最为显著;风速的年内变化表现为偏双峰型,4月最大,形成年内的第一峰值,最低值出现在每年的10月,第二峰值出现在每年的11月。

Based on the data of sunshine duration, wind speed collected at 23 stations from 1959 to 2010 in Wei River Basin, spatial and temporal （for annual, seasonal and monthly） variations of sunshine duration and wind speed, as well as the abrupt change characteristic were analyzed. The result showed that the sunshine duration displayed a decreas ing tendency in the last 52 years with a decreasing rate of 10.13 h/lO a, while a sudden change was found in about 1973. A distinct decrease occurred in Guanzhong Plain in spatial distribution, and the decrease was most prominent in summer and winter in seasonal distribution. The annual average wind speed decreased at a rate of O. 05 m/s per 10 years, while a sudden change was found in about 1981. The decrement rate in the Guanzhong Plain and loess hilly-gully region was higher than that of other parts. The change characteristic of wind speed was double peak type. The first peak appeared usually at April and the lowest wind speed appeared usually at October. The second peak appeared usually at November.