山西万荣县近52a气候特征及其与参考作物蒸散量和土壤湿度的关系

Climatic Characteristics and Its Relationship with Reference Crop Evapotranspiration and Soil Moisture in Wanrong County of Shanxi Province

利用山西省万荣县气象观测资料,分析了1957～2008年气候变化特征。结果表明:万荣县年平均气温呈上升趋势,其上升速率为0.22℃/10 a。平均气温冬季升高最大;年平均最高、最低温度与年平均温度的整体变化一致,呈明显升高趋势。万荣县降水量总体呈减少趋势,其减少速率为22.1 mm/10 a。年日照时数、年小型蒸发皿蒸发量、年平均风速呈下降趋势。年参考作物蒸散量下降速率为21.8 mm/10 a,这与年日照时数减少、年平均风速变小、年平均水汽压增长、年平均最低温度增大有关。麦田年平均土壤湿度呈下降趋势,特别是进入21世纪以来,土壤湿度在小麦生育期下降较为明显。麦田土壤湿度下降的主要原因是降水量的减少。

The climate characteristic was studied on the basis of meteorological observations during the period of 1957-2008 in Wanrong county of Shanxi Province.The results show that annual average temperature increased with a rate of about 0.22 ℃/10 a,and the most evident warming occurred in winter.The annual mean maximum and minimum temperature also presented an increasing trend.The annual precipitation showed a decreasing trend with a rate of 22.1 mm /10 a,and the annual sunshine hours,the annual small pan evaporation and the annual mean wind speed showed decreasing trends,too.The annual reference crop evaporation showed a decreasing trend with the rate of 21.8 mm/10 a,which might caused by the decrease of the annual sunshine hours and the annual mean wind speed,as well as the increase of the annual mean vapor pressure and the annual mean minimum temperature.The soil moisture in wheat field showed a decreasing trend,especially during the 21st century,which mainly caused by the decrease of the annual precipitation.The wheat yield decreased with the decline of soil moisture.Soil drought will become more serious to winter wheat growth.