基于稳定同位素的黄土高原东部非季风期土壤水分连续蒸发定量评估  

Quantitative evaluation of consecutive soil moisture evaporation during the non-monsoon season based on stable isotopes in the eastern Loess Plateau

作　　者：孟思彤 孙从建 陈伟[1,2] 高彩欣 丛佳敏[1,2] MENG Sitong;SUN Congjian;CHEN Wei;GAO Caixin;CONG Jiamin(College of Geography,Shanxi Normal University,Taiyuan 030031;Research Center of Ecological Environment in the Middle Reaches of the Yellow River,Shanxi Normal University,Taiyuan 030031)

机构地区：[1]山西师范大学地理科学学院,太原030031 [2]山西师范大学黄河中游生态环境研究中心,太原030031

出　　处：《干旱区资源与环境》2024年第9期125-137,共13页Journal of Arid Land Resources and Environment

基　　金：山西省基础研究计划(自由探索类)面上项目(202303021221154);河北省重点研发项目(22377001D)资助。

摘　　要：定量评估土壤水分蒸发对于深入了解半干旱区土壤水分运动过程、维系区域生态安全至关重要。文中基于黄土高原东部非雨季生长期(2023年4月1日至2023年6月30日)的土壤水分样品的连续观测,分析了区域土壤水分氢氧稳定同位素的时空变化规律,定量解析了不同深度的土壤水分蒸发损失并探讨了其与主要环境要素间的内在关系。结果表明:1)整体上研究时段SWC呈现出逐渐降低的变化趋势,土壤水分δ^(18)O和δ^(2)H月际间差异显著。2)土壤水δ^(18)O平均值在0-20cm土层最为富集,在40-60cm土层最为贫化。3)土壤水分蒸发损失量(f)在4月最小而5月最大,随着土层深度增加f呈现出波动式下降的变化。4)f与区域大气温度(T)、风速(WS)、潜在蒸散发(ET_(0))呈现出正相关性,与土壤含水量(SWC)、相对湿度(RH)呈负相关性。5)小雨量时(<5mm),f与外界环境要素的关联性较弱,大雨量时(>20mm)时,f与外界环境要素间存在显著的线性关系(P<0.05)。研究结果对于区域水资源的合理优化配置及农业高质量有重要的意义。Soil moisture is the key link between the atmosphere,water circle and soil circle,and its evaporation loss is crucial to understanding the process of soil water movement in semi-arid areas and maintaining the regional ecological environment.Based on continuous collection of long-term stable isotopes in soil water in the typical region of the eastern Loess Plateau during the non-rainy period in growing season,this study systematically analyzes the spatial and temporal variations in soil moisture content and its hydrogen and oxygen stable isotopes,explores the soil water evaporation loss at different soil depths under consecutive evaporation conditions using the Craig-Gordon model,and reveals the internal relationship between soil evaporation loss and major regional environmental elements.Results indicate that:1)The soil moisture content shows a gradual decreasing trend,δ^(18)O andδ^(2)H in soil water appears fluctuation among different months.2)Enriched soil waterδ^(18)O appears in the 0-20cm soil layer,and gradually decreases with the increase of the soil depth,and the minimum value of soil waterδ^(18)O appears in the 40-60cm soil layer,and is gradually enriched with increasing soil depth.3)Overall,the maximum value of soil moisture evaporation loss is observed in May,and the minimum value is observed in April,which shows a fluctuating decreasing trend with increasing soil depth.4)Regional soil moisture evaporation loss is positively correlated with regional air temperature,wind speed and potential evapotranspiration,and negatively correlated with soil water content and relative humidity.The correlation between soil moisture evaporation loss and environmental elements gradually weaken with increasing soil depth.5)The results of multiple linear regression analysis show that the correlation between soil water evaporation loss and external environment elements is weak while precipitation less than 5mm,whereas there is a significant linear relationship between soil water evaporation loss and external environmenta

关 键 词：土壤水分 氢氧稳定同位素 连续蒸发损失 控制因素 

分 类 号：S152.7[农业科学—土壤学]