中文摘要：

基于2016年冻土融化期黑顶子河流域地表水、土壤水和地下水中稳定氢（δD）氧（δ~（18）O）同位素观测数据,分析了该区域融雪产流阶段δD和δ~（18）O的时空变化特征及主要影响因素。结果表明：融化期积雪δD和δ~（18）O平均值最小,分别为-9.33%和-1.28%,且变异性最大。冻土层隔绝了地下水与融雪水的联系,因而地下水、土壤水主要来自冻结期前降雨,其δD和δ~（18）O变异性最小且均匀的分布在大气降水线附近。冻融过程控制了融雪水与土壤水的蒸发速率和混合作用,进而影响了河水δD和δ~（18）O随时间的变化特征。土地利用类型不同导致下垫面之间土壤水和地下水δD和δ~（18）O差异较大。玉米田土壤水主要来自降雨,经历了先入渗再蒸发的过程,呈现表层大深层小的变化趋势。水稻田深层土壤水和地下水主要来自作物生长期灌溉水,经历了先蒸发后入渗的过程,δD和δ~（18）O较大;表层土壤水主要来自冻结期降雨或融雪入渗,δD和δ~（18）O较小。受水稻田地下水补给、河道融冰补给以及蒸发作用的影响,主河道稳定同位素显著大于支流,这种差异的大小与流域水循环活跃程度密切相关。

英文摘要：

The objectives of this study were to investigate the characteristics and controlling factors of stable oxygen and hydrogen isotopes during the thaw period in seasonal freezing area. Results show that δD and δ~（18）O of snow were-9.33% and-1.28%,respectively,which were lowest among all the water samples,and the variability was maximum. The δD and δ~（18）O of soil water and groundwater influenced by precipitation before freezing period were uniformly located beside the local meteoric water line,and the variability was minimum. Freeze-thaw process controlled the temporal variation of δD and δ~（18）O of stream water by influencing the evaporation and mixing of snowmelt water and soil water. The land uses greatly influence the space variation of δD and δ~（18）O of soil water and groundwater. The soil water of maize land was mainly from precipitation,and the surface soil water suffered stronger evaporation,thus the δD and δ~（18）O was rich in surface soil water and then decreased with depth. The soil water and groundwater in paddy land was mostly from irrigation water,which has experienced great evaporation before infiltrating into deep soil,thus the δD and δ~（18）O was rich. On the contrast,the surface soil water in paddy land mostly came from precipitation and snowmelt water,as a result,the δD and δ~（18）O was poor. Affected by paddy land groundwater,ice melt water and evaporation,the δD and δ~（18）O of the main stream was obviously richer than that in tributary,and this difference was related to the activity of water cycle in the watershed.