淮河上中游流域日照时数时空分布特征分析

为揭示淮河上中游流域日照时数时空变化特征及突变情况，基于1960～2014年日照时数资料，采用气候倾向率、Mann-Kendall趋势与突变检验、滑动t检验、克里金插值等方法，对流域日照时数的时空变化特征进行剖析。结果表明，淮河上中游流域近55年来日照时数以20世纪80年代为界由多变少，其中年日照时数大约每10 a减少102.2 h，四季日照时数的气候倾向率排序为夏（-48.8 h/10a）、冬（-29.3 h/10a）、秋（-19.7 h/10a）、春（-5.4 h/10a）。流域日照时数的减小趋势除春季不显著外，年与夏、秋、冬三季的日照时数均呈现出显著的减少趋势。空间上，流域北部的中间地带（商丘站附近）与西北部（宝丰、郑州站附近）的日照时数减小趋势较明显（Z＜-2），减少幅度较大，而东部（盱眙站除外）减少幅度则偏小。年与夏季日照时数的极显著突变年份为1980年，年日照时数的弱显著突变年为1984年。秋季、冬季的突变年份分别为1999年、1983年，春季的突变年份在20世纪70年代内。研究成果可为淮河上中游流域的气候研究、农业生产等提供科学研究依据。

Characteristic analysis of the temporal and spatial distribution of sunshine duration in the upper and middle reaches of Huaihe River Basin

In order to reveal the spatial-temporal variation characteristics of sunshine duration in the upper and middle reaches of Huaihe River Basin and determine the year of mutation, we adopted such methods as the climate tendency rate, Mann-Kendall trend and mutation test, sliding t-test, and Kriging interpolation, and analyzed the spatial-temporal variation characteristics of sunshine duration based on the data of sunshine duration from 1960 to 2014. The results indicated that the sunshine duration in the past 55 years decreased to a lower level in the 1980s; the annual sunshine duration decreased by about 102.2 h every 10 years; and the climate tendency rates of sunshine duration in the four seasons were as follows: summer (-48.8 h/10a), winter (-29.3 h/10a), autumn (-19.7 h/10a), and spring(-5.4 h/10a). The sunshine duration in a year and in all three seasons except spring showed a significant decreasing trend. Spatially, the decreasing trend of sunshine duration was more obvious and sharp in the middle of the northern basin (near Shangqiu station) and in the northwest (near Zhengzhou and Baofeng stations) (Z<-2), but the decrease was small in the east (except for Xuyi station). The highly significant mutation year of annual and summer sunshine durations was 1980, and the weakly significant mutation year of annual sunshine duration was 1984. The mutation years of autumn and winter were 1999 and 1983 respectively, and the mutation year of spring was in the 1970s. The research results are expected to provide scientific basis for the climate studies and agricultural production in the upper and middle reaches of Huaihe River Basin.