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为了探析径流过程中稳定同位素变化特征及其控制因子,利用2008年拉萨河流域地表径流中δ18O和δD的监测数据以及相关气象和水文资料,初步研究了流域δ18O和δD的空间分布特征.研究发现:(1)拉萨河流域以大气降水为主要补给来源,且干流体现了较明显的蒸发效应;(2)河水偏正的d过量参数特征指示了冰雪融水的补给特征;(3)季风降水期间,拉萨河流域由高程效应和水平距离所造成的δ18O递减率约为0.16‰.(100m)-1;(4)大循环尺度下,流域内河水呈现了明显的大陆效应.研究表明高海拔地区地表径流氧氘同位素分布特征能够有效示踪流域水文循环过程,并提供古高度变化研究的稳定同位素证据.
In order to investigate the characteristics of stable isotopes and their controlling factors during the runoff, the spatial distribution features of δ18O and δD in the basin were preliminary studied by using the δ18O and δD monitoring data and related meteorological and hydrological data from the surface runoff in Lhasa Basin in 2008. The findings : (1) The main source of recharge is Lhasa River Basin, and the main stream shows obvious evaporative effect; (2) The overbalanced parameter of river water indicates the replenishment characteristics of snowmelt melt; (3) The monsoon precipitation During the Lhasa River Basin, the δ18O decline rate caused by elevation and horizontal distance was 0.16 ‰ (100m) -1. (4) In large circulation scale, the inland water in the river basin showed obvious continental effect. The research shows that the high altitude The distribution characteristics of oxygen, deuterium isotopes in surface runoff in the area can effectively trace the hydrological cycle of the basin and provide stable isotope evidence for the study of the paleo-altitude changes.