【摘要】 为研究人类活动影响下河流降水径流响应特征,以珠江三角洲典型城镇化流域石马河为研究对象,采集2017年1-12月日降水、河水样品和3场台风期间的时段降水、洪水样品,通过测定其氢氧稳定同位素组成(δD、δ¹⁸O),分析流域降水、径流氢氧同位素组成特征,并利用同位素二元混合模型,分割3场台风降水事件中事前水及事件水对流量过程的贡献。结果表明,研究区域大气降水δD、δ¹⁸O的变化范围分别为-105.10‰～+9.98‰和-14.80‰～-0.55‰,年加权平均值为-57.88‰和-8.61‰,大气降水线为δD=7.70δ¹⁸O+8.61（R²=0.98）;河水δD、δ¹⁸O的变化范围分别为-91.23‰～-15.96‰和-12.66‰～-4.01‰,δD-δ¹⁸O基本落在局地大气降水线上,表明降水是石马河径流的主要来源。3场台风期间,事件水占洪水总径流量的比例分别为59.7%、55.0%和69.4%,均高于事前水占比。洪水涨水初期事前水和事件水同步增长,涨水后期事件水比例逐渐增大,洪峰期间比例大于80%,成为径流主导成分,表明流域城镇化过程中下垫面不透水面积的增加会显著改变水文循环过程。本研究成果可为珠江三角洲城镇化流域水文预报提供理论基础。更多还原

【Abstract】 In order to study the response characteristics of precipitation-runoff under the influence of human activities, this paper took Shima River, a typical urbanized catchment in the Pearl River Delta as the research area. Daily samples of precipitation and river water were collected from January to December and hourly samples were collected during three typhoon rainstorms in 2017. Based on the stable isotope data(δD, δ¹⁸ O), the characteristics of hydrogen and oxygen isotopes were analyzed. Two-component isotope-based hydrograph separation was used to study the contribution of pre-event water and event water to the runoff process during three typhoon events. The results showed that δD and δ¹⁸ O in precipitation ranged from-105.10‰ to 9.98‰ and-14.80‰ to-0.55‰, respectively, and the annual weighted mean values were-57.88‰ and-8.61‰. The Local Meteoric Water Line was δD=7.70δ¹⁸ O+8.61（R²=0.98）. δD and δ¹⁸ O in river water ranged from-91.23‰ to-15.96‰ and-12.66‰ to-4.01‰,respectively. δD-δ¹⁸ O basically fell on the LMWL indicated that precipitation was the main source of runoff in the Shima River catchment. During the three typhoons, the proportion of event water was 59.7%, 55.0% and 69.4%, respectively, which was higher than that of preevent water. In the early stage of flood, pre-event water and event water increased synchronously. In the late stage of flood, the proportion of event water increased gradually which was more than 80% during the peak period. This indicated that the increase of impervious areas in the urban regions would significantly alter the hydrological cycle. The results of this study could provide the theoretical foundations for hydrological forecast of urbanized basins in Pearl River Delta.更多还原