山东省1960—2011年参考作物蒸散量变化特征研究

为了研究山东省参考作物蒸散量（ET0）的变化特征,选取属于湿润气候的成山头站以及属于半湿润气候的惠民站、济南站、潍坊站、定陶站、兖州站6个气象站,利用国家气象资料中心提供的1960—2011年的逐日气象资料,采用距平分析、回归分析和地理信息系统分析了山东省ET0的年代际、年际和年内的时空变化趋势,并通过偏相关分析及标准化偏回归系数对各站ET0的影响因素进行研究。结果表明：半湿润区ET0年代均值大于湿润区ET0年代均值,其中济南站最大,最大值出现在20世纪70年代,达到1269.2 mm,成山头站最小,最小值也出现在20世纪70年代,为900.8 mm;6个站点中,济南站ET0值年际间的变化最大,极差达到351.9mm,定陶的极差最小,为157.8 mm。潍坊的ET0年际波动最大,标准差达到74.4 mm;定陶的年际ET0标准差达到51.4 mm,波动最小。6个站点的ET0年均值随时间呈现不同程度的降低,其中潍坊和兖州为极显著,济南和定陶为显著降低。ET0年均值在空间上的分布规律为：济南站〉潍坊站〉惠民站〉兖州站〉定陶站〉成山头站;6个站点的ET0都是夏季最高,冬季最低。春季平均ET0值中部地区最大,达到409.0 mm,东北部沿海区最小,只有237.2 mm。夏季平均ET0值的空间分布与全年平均ET0值的空间分布较为一致,只在惠民站为中心的小区域内出现降低,与周围区域有反差。秋、冬季平均ET0值在中部及东北部均较大,东北部最大,西南部及西北部较小,最小值出现在西南地区。半湿润气候的惠民站、济南站、潍坊站、定陶站、兖州站的ET0随时间的年内变化曲线为单峰型,峰值均出现在夏季6月,全年的第162天。湿润气候下成山头站的ET0随时间的年内变化曲线呈双峰型,峰值分别出现在春季5月,全年第150天以及秋季9月,全年第270天;山东省ET0与气象要素间的相关性很好,除成山头站的最低气温外,均达到极显著水平。影响山东省湿润气候和半湿润气候ET0变化的主要气象要素分别为最高气温和平均气温。

Variation characteristics of reference crop evapotranspiration from 1960 to 2011 in Shandong province

To study variation characteristics of reference crop evapotranspiration （ET0） in Shandong province, this study chose Cheng Shantou Station which located in semi-humid areas, and Huimin Station, Jinan Station, Weifang Station, Dingtao Station and Yanzhou Station which situated in humid region to analyse decadal, inter-annual and annual variation tendency of ETo by distance average analysis, regression analysis and geographical information system, using daily meteorological data from 1960 to 2011 pro- vided by National Climatic Data Center. Influencing factors of ET0 were found through partial correlation analysis and standardized partial regression coefficient. The results showed that the deeadal mean ET0 in semi-humid region was greater than that in humid region. Both the greatest and the smallest value of the mean ET0 were showed in 1970s. The maximum mean ET0 was 1 269.2 mm in Jinan Station, while the minimum was 900.8 rnm in Cheng Shantou Station. In all of these stations, the greatest change of annual ETo was in Jinan Station with the range of 351.9 mm, and the minimal change appeared in Dingtao Station with the range of 157.8 mm. The biggest inter-annual fluctuation was in Weifang Station with the standard deviation of 74.4 mm and the smallest was in Dingtao Station with the standard deviation of 51.4 mm. The annual ET0 decreased differently in these 6 stations, annual ET0 in Weifang Station and Yanzhou Station decreased very significantly, and it reduced significantly in Jinan Station and Dingtao Station. When it came to the spatial distribution regularities of annual average value of ET0, the sequence in descending was Jinan Station, Weifang Station, Huimin Station, Yanzhou Station, Dingtao Station, and Cheng Shantou Station. ET0 had higher values in summer and the lower ones in winter. In spring, the greatest average ET0 showed in central region, which reached 409.0 mm, while, it was only 237.2 mm in the northeast coastal zone. The spatial distribution of average ET0 in summer was somewhat similar to that of annual average ETo, but there was reduction in a small area taking Huimin Station as center. In autumn and winter, it was greater in the central and northeast area, the greatest in the northeast, the smaller in the southwest and northwest, and the smallest in the southwest. ET0 change curve of the five sites in semi-humid areas on annual scale was single peak type with the peak in June, the 162th day of the year, whereas, ET0 change in humid climate areas in a year showed double-peak curves, and the peaks occurred in May, the 150th day and autumn, and September, the 270th day respectively. The correlation between ET0 and meteorological elements in Shandong Province reached very significant level in addition to the lowest temperature in Cheng Shantou Station. Main meteorological elements which influenced ET0 variation in humid climate and semi-humid climate in Shandong Province were the highest temperature and the aver- age temperature.