西安地区土壤浅层温度变化特征

Characteristics of shallow soil temperature changes in Xi’an area

利用西安地区1961-2017年的逐月5、10、15、20cm浅层地温观测数据,采用气候诊断方法,研究了西安地区土壤浅层温度的时间变化趋势,以及地温随土层深度的变化特征,探讨了影响地温变化因素。结果表明:西安地区各浅层年季平均地温有显著上升趋势,以郊区地温变化率最大,城区地温变化率较小,地温随土层深度变化有差异。土层越深,趋势率越小,春夏两季地温随土层深度增加而下降,秋冬两季土层深度越深而地温越高。同时也检测出地温具有周期、突变及异常特征。分析认为气温升高是影响地温变化的主要因素,下垫面性质及地热传导与地温的空间变化有密切关系。

Based on the 5,10,15 and 20 cm shallow ground temperature observation data of four meteorological observation stations in Xi’an from 1961 to 2017,using climate tendency rate,MK test and wavelet analysis methods,the trends,mutation characteristics,abnormal years and periodic characteristics of shallow ground temperature were analyzed.The results show that the annual average shallow ground temperature of 5,10,15 and 20 cm in Xi’an area were increasing significantly with the increase of soil depth in the vertical direction.The ground temperature in spring and summer decreased with the increase of soil depth,but were increasing with the increase of soil depth in autumn and winter.At the same time,the ground temperature showed periodicity,mutation and abnormal characteristics.The analysis shows that the temperature,underlying surface properties and geothermal conduction had a great influence on the ground temperature.