中文摘要：

利用海河流域2012年7月-2013年1月7个观测站点大气降水中的δD和δ^18O数据,研究了流域降水稳定同位素的时空变化特征.结果表明流域降水稳定同位素季节变化具有明显的空间差异,南部站点降水稳定同位素值季风期（7-9月）相对贫化,非季风期相对富集;而流域北部站点则相反.这种季节上的空间差异主要反映了不同水汽来源和气候要素的控制,季风期间,受海洋水汽（d〈8.4‰）影响,流域降水中稳定同位素值普遍较低,而非季风期间由于大陆水汽（d〉14.1‰）影响,其降水中同位素以高值为特征;在日和月时间尺度上,降水中稳定同位素变化在流域南部地区（除惠民站外）表现出显著的降水量效应,而在北部地区则表现为显著的温度效应.流域降水易受到云底二次蒸发的影响,特别是在季风期间,受其影响,流域大气水线的斜率和截距显著降低.

英文摘要：

Stable isotopes of δ^18O and δD in precipitation are investigated in the Haihe River basin, north China, based on observations at seven stations from July 2012 through January 2013. The results show that precipitation isotopes had a spatially distinct difference between monsoon （July through September） and non-monsoon seasons. In the southern basin, isotope depletion during the monsoon period was closely tied to Pacific- and Indian-sourced moisture （deuterium excess （d）〈8.4‰） and subsequent amount effect, whereas the relatively high isotope values during the non-monsoon period resulted from isotopically-enriched, continental-sourced moisture. In contrast, in the northern basin, moisture was derived mainly from dry continental air masses （d〉14.1%,） and the isotope values were largely controlled by the temperature effect, exhibiting a seasonality with isotopically-enriched summer and isotopically-depleted winter. Precipitation isotopes in the basin are prone to subcloud evaporation during the summer season, as revealed by small slope （7.1） and intercept （-4.6%0） of the local meteoric water line. This was only the case for the plain area of the basin during the non-monsoon period. The results presented here may provide some constraints on water isotope interpretation and modem isotope hydrological processes in the basin.