陕南汉江上游气温变化及其对农业生产的影响

Temperature Changes and its Impacts on Agriculture in the upper Reaches of Hanjiang River in Southern Shaanxi

以陕南汉江上游汉中、石泉、安康观测站1960-2010年的逐日、逐月平均气温资料为基础,采用线性趋势法、滑动平均法和Mann-Kendall非参数检验法,分析了该区气温的年际和季节变化趋势、突变特征,以及季节气温变化对农业的影响。结果表明,自1960年以来,陕南汉江上游年平均气温和年平均最低气温呈波动上升的变化趋势,递增速率分别为0.107℃/10a(P<0.01)、0.16℃/10a(P<0.01),而年平均最高气温呈不显著递增趋势,三者发生突变的时间分别为2001、2000和2001年;各季节的变化特征表现为冬季增温速率最高(P<0.01),对年平均气温增加的贡献最大;夏季气温变幅较小,变化趋势不显著;春、秋季气温分别呈极显著、显著上升趋势,但日波动性较大;倒春寒天气发生时间推迟,发生频率、强度增大;秋封(冷害)发生频率虽然有所下降,但持续时间较长,强度较大,对该区的水稻、玉米、小麦等农作物生产造成严重影响。深入了解汉江上游气候变化规律及成因,对有效应对气候变化和保障粮食安全具有积极意义。

The variation and mutation of temperature at inter-annual and seasonal scales and their impacts on agriculture were analyzed,by using of linear trend analysis,moving average methods and Mann-Kendall,based on daily and monthly average temperature data of 3 stations in the upper reaches of Hanjiang river in Southern Shaanxi from 1960 to 2010.The results showed that the annual average temperature and annual average minimum temperature increased generally at the rate of 0.107℃/10y（P＆lt;0.01）and 0.16℃/10y（P＆lt;0.01）respectively,but annual average maximum temperature did not increased obviously.The mutation point for annual average temperature,annual average minimum temperature,and annual average maximum temperature were detected in 2001,2000 and 2001 respectively.The seasonal change showed that greater in winter（P＆lt;0.01）,and it had large contribution to climate warming.Temperature decreased a little in summer,but increased extreme significantly in spring and significantly in autumn.Late spring coldness delayed,with high intensity and high frequency.The frequency of autumn chilling decreased with longer duration greater intensity.Therefore,late spring coldness and autumn disasters caused a serious damage on crop production,including rice,maize and wheat.It was help for adapting to climate change and ensuring food security to understand climate change and its mechanism in upper Hanjiang river.