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通过对黑河源区不同水体稳定氢(δD)和氧(δ18O)同位素比率的测定及对过量氘(d-excess)的计算,结合美国环境预报中心和国家大气研究中心(NECP/NCAR)再分析资料,对研究区大气水汽来源及地表径流组成进行了初步研究.结果表明,黑河源区各样点降水δ18O季节变化的一致性表明其水汽来源相同;夏季,野牛沟大气降水δ18O和δD值偏正而d-excess为低值,冬季降水的δ18O和δD偏负而d-excess增加,其季节变化特征与乌鲁木齐降水同位素特征相似,显示该区域夏季降水主要来源于西风输送,冬季降水除受西风控制外还受极地气团的影响.野牛沟全年较高的d-excess值表明,由于地处西北内陆干旱区,黑河源区不同水体的内循环特征非常明显.黑河源区不同水体的δD,δ18O和d-excess时间变化表明不同潜在水源对黑河源区地表径流的贡献不同.如5~9月份降水和河水的δD,δ18O和d-excess及12~2月泉水与河水的δ18O变化的一致性、降水量与出山径流相似的季节变化规律及9月份融水与河水δ18O的显著差异等均说明在黑河源区,降水对地表径流的主要贡献时段在6~9月中旬;冬季主要以基流(以泉水的形式)补给河水为主,但流量较低.
Based on the determination of isotopic ratios of δD and δ18O in different water bodies and the calculation of excess deuterium (d-excess) in the Heihe River source area, a reanalysis was conducted with the US Environmental Prediction Center and the National Center for Atmospheric Research (NECP / NCAR) Data of the study area to study the sources of atmospheric water vapor and surface runoff composition of the preliminary study showed that the Heihe River source of various samples of precipitation δ18O seasonal changes in the consistency of the same source of water vapor; summer, Ye Niugo precipitation δ18O and δD values Positive δ-dO and δD are negatively correlated with δ-D and d-excess increase in winter, while the seasonal variation is similar to that of Urumqi precipitation. The results show that the summer precipitation in this region mainly comes from the westerlies, and the winter precipitation is dominated by westerly winds Control also affected by the polar air mass.The high d-excess values in the whole year showed that the internal circulation characteristics of different water bodies in the Heihe River source area were very obvious due to the inland arid zone in the northwest China.The δD , δ18O and d-excess showed that the contribution of different potential water sources to surface runoff in the Heihe River source area was different. For example, the δD, δ18O and d-excess of precipitation and river water from May to September and spring water from December to February The consistency of δ18O in water, the seasonal variation of precipitation and runoff, and the significant difference of δ18O between meltwater and river water in September indicate that the main contribution period of rainfall to surface runoff in June-September In mid-winter, basing on spring (mainly in the form of spring water), river water was mainly used but the flow rate was relatively low.