长江源区土壤水稳定同位素特征研究
Study on stable isotope characteristics of soil water in the source region of Yangtze River
刘晓颖 1何宝军 2李宗杰 1刘梦晴 1徐斌 1桂娟 3崔乔 3赵越 3薛健 3段然1
作者信息
- 1. 兰州理工大学 能源与动力工程学院,甘肃 兰州 730050
- 2. 中国地质调查局军民融合地质调查中心,四川 成都 610036
- 3. 中国科学院 西北生态环境资源研究院 高寒山区同位素生态水文与国家公园观测研究站/甘肃省祁连山生态环境研究中心/干旱区生态安全与可持续发展重点实验室,甘肃 兰州 730000
- 折叠
摘要
本文通过采集长江源区土壤样品,对不同深度土壤水分稳定同位素变化特征及其空间分布特征进行分析,使用端元混合径流分割模型对土壤水的来源进行计算,结果表明:土壤温度在0～100 cm范围内呈下降趋势,土壤含水率在0～80 cm范围内呈下降趋势,80～100 cm范围内呈上升趋势;土壤水的δ2H和δ18O值在0～100 cm深度范围内波动变化,且变化趋势相似,土壤水的δ18O及δ2H值变化范围分别为-151.273‰～-63.605‰和-21.052‰～-8.676‰.土壤水的δ2H和δ18O在空间上总体呈西部富集,而东南部贫化的特点;蒸发线(EL)为δ2H=7.23δ18O-5.27(R2=0.88);土壤水稳定同位素受到海拔梯度和土壤含水率的影响;降水对土壤水的贡献高于地下冰融水,且随着海拔梯度的增加,降水对土壤水分的贡献率呈现增加趋势,在4 150～4 777 m范围内降水对土壤水的贡献率为70%～94%;地下冰融水在海拔4 150～4 555 m范围内对土壤水的贡献率为8%～30%,在海拔4 613～4 777 m范围内贡献率下降,为6%～8%.本研究为深入了解长江源区土壤水分运动及稳定同位素研究提供了理论依据.
Abstract
Through the collection of soil samples,this study analyzed the characteristics of stable isotope varia-tions and their spatial distribution in soil water at different depths in the source region of Yangtze River.The sources of soil water were determined by the study using an end-element mixed runoff partition model.The find-ings revealed that within the range of 0～100 cm,soil temperature exhibited a decreasing trend,while the region of 0～80 cm and the range of 80～100 cm showed a rising tendency in soil moisture content.Within the depth range of 0～100 cm,the δ2 H and δ18 O values of soil water varied,and their trends were similar.The range of vari-ation for the soil water's δ2 H and δ18 O values was,respectively,-151.273‰ to-63.605‰ and-21.052‰ to-8.676‰.Spatially,soil water's δ2 H and δ18 O content was often enhanced in the western and depleted in the southeast.The evaporative line(EL)was represented by δ2 H = 7.23δ18 O-5.27(R2=0.88).The altitude gradi-ents and soil moisture content had an impact on the stable isotope composition of soil water.The contribution of precipitation to soil moisture increased with increasing altitude gradient,and it was greater than the input of melt-water from ice melt water.Precipitation accounted for 70%to 94%of the soil's water content between 4 150～4 777 m above sea level.Between 4 150～4 555 m above sea level,ice melt water contributed 8%to 30%of soil water;between 4 613～4 777 m above sea level,it reduced to 6%to 8%.In an effort to improve our understand-ing of soil water circulation and stable isotope research in the source region of Yangtze River,this study provides a theoretical basis.
关键词
同位素特征/土壤水/长江源区/贡献率Key words
isotopic characteristics/soil water/source region of Yangtze River/contribution rate引用本文复制引用
基金项目
国家自然科学基金项目(42107063)
国家自然科学基金项目(42077187)
甘肃省重点研发计划项目(23YFFA0062)
第二次青藏高原综合科学考察研究项目(2019QZKK0405)
中国科学院青年交叉团队项目(JCTD-2022-18)
国家重点研发计划(2020YFA0607702)
中国科学院"西部之光"交叉团队项目重点实验室合作研究专项()
兰州理工大学红柳优秀青年人才支持计划()
出版年
2024
NETL
NSTL
万方数据