地质科技情报2011，Vol.30Issue(5)：103-109,7.
黑河中游临泽地区沙丘植物水分来源的D、18O同位素示踪
Using D and 18O Stable Isotopes to Determine the Water Sources of Sand Dune Plants in Linze, Middle Reaches of Heihe River
摘要
Abstract
Using the measured δD and δ18O values of rainfall, groundwater and waters extracted from vegetation and soils, this paper discussed the sources of soil water at different depths at the top and bottom of one sand dune in Linze, middle reaches of Heihe River, and determined the soil layers from which three sand dune plants extract water, and the dependence of these plants on the rainfall and groundwater. The results showed that, when viewed as a whole, δD and δ18O values of soil water declined as a typical exponential function of depth, except that some details of the exponential curve were altered by the infiltration of individual rainfall events. It was indicated that the soil profiles were affected by evaporation and infiltration of rainfall along the top boundary and received recharge from phreatic aquifer through the bottom boundary. Soil water might be recharged by the latest rainfall event for the upmost layer to a depth of 20 cm or 30 cm, by all rainfall events occurring in recent 1 -2 weeks for the medium layer from 20 cm or 30 cm to 130 cm in depth, and mainly by phreatic water, accidently mixed with earlier extensive rainfall e-vents, for the bottommost layer under a depth of 130 cm. Hedysarum scoparium extracted soil water from 120 cm to 180 cm in depth at the bottom of the sand dune. Tamarix ramosissima Ledeb and Haloxylon ammodendron, at both the bottom and top of the sand dune, and Hedysarum scoparium at the top of the sand dune, extracted soil water under the depth of 185 cm. It was presumed that the sand dune plants here mainly relied on the more stably available phreatic water, accidently using the rainfall with a large limit depth of infiltration.关键词
稳定氢氧同位素/植物水分来源/黑河/干旱区Key words
stable hydrogen and oxygen isotopes/ water source of plant/ Heihe River/ arid region分类
地质学引用本文复制引用
周辰昕,孙自永,余绍文..黑河中游临泽地区沙丘植物水分来源的D、18O同位素示踪[J].地质科技情报,2011,30(5):103-109,7.基金项目
国家自然科学基金项目(40702042) （40702042）
