青海贵德旱作区春秋季土壤水分变化特征

Variation Characteristics of Arid Farmland Soil Moisture in Spring and Autumn in Guide, Qinghai

运用青海省贵德县气象局观测的2002—2014年旱地土壤水分资料,分析了该地区0~30 cm土壤水分变化特征,结果显示：2002—2014年,春季贵德旱地0~30 cm土壤含水量呈显著降低趋势,秋季土壤含水量则呈不显著增多趋势,年际变化很明显。各层土壤水分变化趋势与整体一致,秋季各层土壤含水量的变幅较春季大。0~10、10~20 cm土壤含水量一年中的最高、最低值分别出现在9月下旬和3月上旬,而20~30 cm土壤含水量的最高、最低值分别出现在10月上旬和4月中旬。自2000年以来,贵德旱作地区春季气温显著升温,但降水却无明显变化,而秋季平均气温升温趋势不明显,降水量却呈显著增多,这种气候趋势与春季土壤含水量逐年减少、秋季土壤含水量逐年增加的结论相一致。

The variation characteristics of 0-30 cm soil moisture in Guide, Qinghai were analyzed based on thearid farmland soil moisture data of Guide weather bureau from 2002 to 2014. The results showed that soilmoisture of 0- 30 cm layer in arid farmland decreased significantly in spring during 2002 to 2014, but itshowed an insignificant increasing trend in autumn, interannual variation was obvious. Soil moisture content ineach soil layer followed the same change rule, but the variation amplitude of autumn was higher than that ofspring. The highest and lowest soil moisture content of 0- 10 and 10- 20 cm soil layer presented in lateSeptember and early March, while the highest and lowest soil moisture content of 20-30 cm layer presented inearly October and mid-April. Since 2000, the spring air temperature rose significantly, but the precipitationhad no apparent change, while the average autumn temperature increase was not obvious, but the precipitationincreased significantly. This climate trend was consistent to the conclusion that the soil moisture contentdecreased year by year in spring and increased year by year in autumn.