季节性冻融期不同地下水位埋深下土壤温度变化特征

Soil Temperature Characteristics Under Different Groundwater Level during Seasonal Freezing-Thawing Period

土壤温度是土壤热状况的综合表征指标,影响土壤养分分布和冬春季节作物生长发育。以山西省水文水资源勘测局太谷均衡实验站为试验基地,对冻融期4种不同地下水位埋深下的土壤温度进行了分析研究。结果表明:在地下水浅埋区,冻融期地温的变化滞后气温变化,且滞后时间随土壤深度的增加而增大。12月初—2月下旬,地下水位为1.0m埋深的土壤温度较高;消融期地下水位为1.5m埋深下的土壤温度迅速回升,而0.5m埋深下的土壤温度较低且回升较慢;同一地下水埋深下,随着土壤深度的增加,剖面温度增高,50cm深度之下的土壤温度受地下水位埋深的影响较弱。研究成果可为冬春作物播种、预防冻害提供参考依据。

Soil temperature is the comprehensive characteristic index of soil heat condition, influences the soil nutrient distribution and the growth of crop in spring and winter. The experiments were conducted in Taigu water balance experimental field, bureau of hydrology and water resources survey of Shanxi province. Soil temperature under four kind of groundwater level during the seasonal freezing-thawing period are analyzed in the paper. Results show that soil temperature variation is later than air temperature variation in shallow groundwater areas during freezing-thawing period and the lagging time is increasing with the increase of soil depth. From early December to late February, soil temperature is higher when water depth is 1.0m. Soil temperature is increasing rapidly when water table is 1.5m, but soil temperature is lower and increasing slowly when water table is 0.5m during the thawing period. With the increasing of soil depth, profile temperature is increased at the same water table and water table has little influence on soll temperature under the depth of 50cm. Research results could provide the references for crop planting and the cold damage prevention in winter and spring.