石家庄市土壤水分运移的稳定同位素特征分析
发布时间：2018-07-31 08:27
【摘要】：华北平原的水资源问题日益严峻,尤其以石家庄市区为代表的城市,人口多、经济较发达,降水量减少,水资源紧缺,生态系统变脆弱。由于地下水位逐年下降,土壤水在水资源合理利用和生态系统水循环中的作用更为重要。根据2013年4月到2014年5月测得的石家庄市区降水和2013年石家庄市雨季土壤水、灌溉水的稳定氢氧同位素,通过稳定同位素示踪的方法,结合对土壤机械组成的测定分析,从时间和空间的角度分析了不同土壤层水稳定同位素的变化规律,进而推断土壤水分迁移过程。研究结果表明:石家庄2013年全年的降水量为596.55mm,样地降水的大气降水线为y=6.547x-1.667(R2=0.941,p0.001),过量氘均值为6.1885‰,反映了石家庄2013—2014年降水主要来自季风带来的海洋水汽,同时有一定的局地蒸发。石家庄土壤水的来源主要是降水,灌溉水则主要在雨季前期有缓解干旱的辅助作用,且雨季的降水量足以对土壤进行适当补给。石家庄市土壤机械组成的测定结果表明,石家庄市0—100cm土壤质地都属于壤土层,0—70cm为较粗的沙粉壤土,80—100cm为较细的粉土壤土。70—80cm是比较明显的土层交接层,容易出现土壤水积聚。从不同的时间尺度上对土壤进行取样,分析土壤水分运移过程,研究结果表明:(1)4月份的一次较大降水之后,降水在土壤中的入渗速度并不均匀,40-70cm处为100mm/d,70-80cm入渗速度为33mm/d。由于土壤质地和降水时间、降水量的影响,土壤水的垂直入渗呈由快到慢的过程,70cm常为阻隔层。(2)从5月开始对土壤水每半个月一次的观测得知,10cm到100cm土壤水的δ18O值随深度增大而减小;雨季最大蒸发深度在40cm左右,5月和9月由于降水量较少,土壤水的蒸发作用最为明显,都达到了40cm的蒸发深度;5月到9月取样期间基本上形成了一个土壤水δ18O峰值沿剖面徘徊中不断向下推进的情况,0—70cm受土壤水入渗的影响较80—100cm明显,此过程反映了降水的入渗和新旧水混合的相互作用。
[Abstract]:The problem of water resources in North China Plain is becoming more and more serious, especially in Shijiazhuang city, where the population is large, the economy is more developed, the precipitation is reduced, the water resources are in short supply, and the ecosystem is fragile. Soil water plays a more important role in the rational utilization of water resources and ecosystem water cycle due to the decrease of groundwater level year by year. According to the precipitation in Shijiazhuang city from April 2013 to May 2014 and the stable hydrogen and oxygen isotopes of soil water and irrigation water in the rainy season of Shijiazhuang city in 2013, the stable hydrogen and oxygen isotopes of irrigation water were analyzed by using the method of stable isotope tracer and the determination and analysis of soil mechanical composition. From the point of view of time and space, the variation law of water stable isotopes in different soil layers was analyzed, and the process of soil water migration was inferred. The results show that the precipitation of Shijiazhuang in 2013 is 596.55mm, the precipitation line of sample land is y=6.547x-1.667 (R2C0.941kp0.001), the average deuterium excess is 6.1885 鈥，
本文编号：2155008
[Abstract]:The problem of water resources in North China Plain is becoming more and more serious, especially in Shijiazhuang city, where the population is large, the economy is more developed, the precipitation is reduced, the water resources are in short supply, and the ecosystem is fragile. Soil water plays a more important role in the rational utilization of water resources and ecosystem water cycle due to the decrease of groundwater level year by year. According to the precipitation in Shijiazhuang city from April 2013 to May 2014 and the stable hydrogen and oxygen isotopes of soil water and irrigation water in the rainy season of Shijiazhuang city in 2013, the stable hydrogen and oxygen isotopes of irrigation water were analyzed by using the method of stable isotope tracer and the determination and analysis of soil mechanical composition. From the point of view of time and space, the variation law of water stable isotopes in different soil layers was analyzed, and the process of soil water migration was inferred. The results show that the precipitation of Shijiazhuang in 2013 is 596.55mm, the precipitation line of sample land is y=6.547x-1.667 (R2C0.941kp0.001), the average deuterium excess is 6.1885 鈥，
本文编号：2155008
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