利用1972—2012年石家庄城市站和4个乡村站地面风速资料,采用城乡对比方法,对石家庄城市站地面风速序列中的城市化影响进行分析,结果表明,石家庄站年和季节平均地面风速和平均10min最大风速的长期下降趋势,主要是由城市化因素引起.具体结论如下:(1)石家庄站年和四季平均风速、平均10min最大风速和大风日数均呈极显著的减少趋势,年平均减少速率分别为-0.15(m/s)/10a、-1.05(m/s)/10a和-2.90d/10a;乡村站年平均风速呈微弱下降趋势,年平均10min最大风速减少较为明显,年大风日数减少趋势非常显著,减少速率分别为-0.02(m/s)/10a、-0.21(m/s)/10a和-2.19d/10a.(2)石家庄站年平均风速下降趋势中的城市化影响为-0.13(m/s)/10a,城市化影响非常显著,城市化贡献率达到86.0%.该站春、夏、秋、冬季平均风速变化的城市化影响分别为-0.16(m/s)/10a、-0.10(m/s)/10a、-0.13(m/s)/10a和-0.15(m/s)/10a,城市化贡献率分别为82.8%、87.6%、88.6%和85.4%.(3)石家庄站年平均10min最大风速变化趋势中的城市化影响为-0.84(m/s)/10a,城市化贡献率为79.7%;春、夏、秋、冬季平均10min最大风速变化趋势中的城市化影响分别为-0.94(m/s)/10a、-0.80(m/s)/10a、-0.60(m/s)/10a和-1.01(m/s)/10a,城市化贡献率分别达到90.4%、78.6%、64.9%和79.1%.(4)城市化对石家庄站年大风日数减少的影响不显著,但冬季大风日数减少仍明显与城市化过程有关.%Based on data of the surface wind speed at Shijiazhuang city meteorological station (simplified as Shijiazhuang station) and four rural meteorological stations during 1972-2012,urbanization effect on the surface wind speed series at Shijiazhuang station was analyzed using an urban-rural difference method. The results showed that: (1) In 1972-2012,there were very significant decreased trends on annual and seasonal mean wind speeds,mean maximum wind speeds of 10 min and gale days at Shijiazhuang station,and the annual mean decreased trends were -0.15 (m/s)/10a,-1.05 (m/s)/10a and -2.90 d/10a respectively. Annual mean wind speed of rural stations showed weakly decreased trend,the decreased trend on annual mean maximum wind speed of 10 min was more obvious,and the decreased trend on annual gale days was very significant. The decreased trends on annual mean wind speed,annual mean maximum wind speed of 10 min and annual gale days at rural stations were -0.02 (m/s)/10a,-0.21 (m/s)/10a,and 2.19 d/10a,respectively; (2) In the study period,urbanization effect on the annual mean wind speed at Shijiazhuang station was -0.13 (m/s)/10a,which was very significant,and the urbanization contribution reached 86.0%,indicating that the urbanization effect is large and significant. Urbanization effect on the mean wind speeds of the urban station in spring,summer,autumn and winter were-0.16 (m/s)/10a,-0.10 (m/s)/10a,-0.13 (m/s)/10a and -0.15 (m/s)/10a respectively,and the urbanization contributions were 82.8%,87.6%,88.6% and 85.4%,respectively; (3) Urbanization effect on the annual mean maximum wind speed of 10 min at the urban station was -0.84 (m/s)/10a,and the urbanization contribution was 79.7%. Urbanization effects on the seasonal mean maximum wind speed of 10 min were -0.94 (m/s)/10a,-0.80 (m/s)/10a,-0.60 (m/s)/10a and -1.01 (m/s)/10a,respectively for spring,summer,autumn and winter,with the urbanization contributions of 90.4%,78.6%,64.9% and 79.1%,respectively; (4) Urbanization effect on the annual gale days at Shijiazhuang station was not significant,but the urbanization effect on the winter gale days was large and significant.
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