内蒙古荒漠草原南缘春季消融期土壤水热变化特征及其对气象因子的响应

Soil water and temperature during spring ablationperiod and its response to meteorologicalfactors in the southern margin of thedesert steppe in Inner Mongolia

摘要:

基于内蒙古荒漠草原南缘2009-2018年的土壤温湿度与气温降水实测数据,利用统计学、相关性分析及回归分析相结合的方法研究了春季消融期内蒙古荒漠草原土壤温湿度的动态变化及相互关系。通过研究荒漠草原在消融过程中土壤水热的变化规律及相互影响,揭示气象因子对土壤温湿度的影响,并为调整牧业发展模式及恢复生态环境提供科学依据。结果表明:在该时期,土壤温度总体呈上升趋势,土壤湿度呈先增长后下降的趋势,100 cm以上的土壤在4月中旬完全解冻;20 cm土壤温湿度呈正弦函数的昼夜周期变化,各层土壤温湿度呈显著正相关,随着土壤温度达到一定程度,土壤温湿度正相关减弱;气温降水与土壤温湿度均呈显著正相关,且不同时间尺度下相关性存在差异,气温对土壤温湿度的影响有滞后效应。得出土壤温湿度存在明显的日际与日内变化规律,土壤的日消夜冻现象明显,土壤温湿度的正相关关系在达到一定阈值后有所减弱,不同时间尺度下气温与降水对土壤温湿度的相关性存在差异性,气温对土壤温湿度的影响存在滞后效应。

Abstract:

This study investigated the change in soil water,heat and their interaction in the desert steppe during the spring ablation process.The study aimed to reveal the influence of meteorological factors on soil temperature and moisture,therefore providing scientific basis for adjusting the development model of animal husbandry and restoring ecological environment.Using the measured data on soil temperature and moisture,air temperature and precipitation on the southern margin of the desert steppe in Inner Mongolia from 2009 to 2018, statistical methods such as geostatistics,correlation and regression analysis were used to study the dynamic changes and mutual relationship between soil temperature and moisture during the spring ablation period.During this period,the soil temperature generally showed a rising trend,while the soil moisture initially increased followed by a decrease.The soil in the 100 cm layer was completely thawed in mid-April.The soil temperature and moisture in the top 20 cm layer showed a periodic day-night variation with a sine function line.The soil temperature and moisture of each soil layer showed a significant positive correlation,but when the soil temperature reached a certain level,the positive correlation between soil temperature and moisture weakened.Both air temperature and precipitation showed significantly positive correlation with soil temperature and moisture,and the correlations were different at different time scales.The influence of air temperature on both soil temperature and moisture had a lag effect.Soil temperature and moisture had obviously daily and diurnal changes.The phenomenon of soil melting during the day and freezing at night was obvious.The positive correlation between soil temperature and moisture was weaker when reaching a certain threshold.There were differences in the correlation between air temperature and precipitation on soil temperature and moisture at different time scales,and the influence of air temperature on soil temperature and moisture had a lag effect.