热带地理 ›› 2020, Vol. 40 ›› Issue (2): 335-345.doi: 10.13284/j.cnki.rddl.003214

• 论文 • 上一篇    下一篇

贵州夜郎湖表层水体地球化学昼夜变化及其影响因素

王家录1,2, 任娟1, 王勇1(), 李维杰1, 娄昭2, 陈佳3   

  1. 1.西南大学 地理科学学院//岩溶环境重庆市重点实验室,重庆 400715
    2.安顺学院 资源与环境工程学院,贵州 安顺 561000
    3.中国科学院普定喀斯特生态系统观测研究站,贵州 普定 562100
  • 收稿日期:2019-10-18 修回日期:2019-12-12 出版日期:2020-03-10 发布日期:2020-05-15
  • 通讯作者: 王勇 E-mail:190966549@qq.com
  • 作者简介:王家录(1969—),男,贵州织金人,副教授,博士生,主要研究方向为岩溶环境与全球变化,(E-mail) lu226@163.com。
  • 基金资助:
    贵州省科技合作计划项目(黔科合LH字[2015] 7702 号);贵州省科技合作计划项目(黔科合LH字[2017] 7059 号);贵州省科技计划院士工作站项目(黔科合平台人才[2016] 5602 号)

Diel Variations of Hydrochemistry and Influencing Factors in the Surface Water of the Yelanghu Reservoir in Puding, Guizhou Province

Wang Jialu1,2, Ren Juan1, Wang Yong1(), Li Weijie1, Lou Zhao2, Chen Jia3   

  1. 1.Chongqing Key Laboratory of Karst Environment//School of Geographical Sciences, Southwest University, Chongqing 400715, China
    2.School of Resources and Environmental Engineering, Anshun University, Anshun 561000, China
    3.Puding Karst Ecosystem Observation and Research Station, Chinese Academy of Sciences, Puding 562100, China
  • Received:2019-10-18 Revised:2019-12-12 Online:2020-03-10 Published:2020-05-15
  • Contact: Wang Yong E-mail:190966549@qq.com

摘要:

为探究岩溶水库水文地球化学行为过程,对贵州普定夜郎湖表层水体进行了为期3 d的高分辨率昼夜监测。结果表明:1)多变的天气和水文条件叠加导致水体离子指标昼夜变化不显著,规律性较差。而水温、DO、pH值、SpC、SIc、pCO2等常规理化指标受水温变化和生物作用表现出明显的昼夜波动。2)利用亨利常数和主成分分析,得到温度变化、生物作用、人类活动、水库的蓄水与放水对夜郎湖水库水文地球化学特征变化的贡献率分别为21.66%、17.28%、14.08%和10.22%,说明作用于水库水文地球化学行为的因子具有多元性。3)δ 18O表现出与DO一致的波动趋势,即白天上升,晚上下降,反映在短时间尺度上,氢氧稳定同位素变化受控于生物过程(主要是呼吸作用过程);而对比水库水体和大气降水的d-excess(d值)发现,水库水体的d值(8.21‰)显著偏低于当地大气降水的d值(9.64‰),说明在长时间尺度上,主要受蒸发效应引起的不平衡分馏影响。

关键词: 表层湖水, 水化学, 氢氧稳定同位素, 昼夜变化, 夜郎湖, 贵州

Abstract:

A karst reservoir is a type of semi-natural and semi-artificial water body. Owing to the dual regulation of fragile geological background of the karst and human activities, the geochemical indexes of karst water body differ considerably. To understand the variation processes of hydrochemistry of the Yelanghu karst reservoirs, which are located in Puding in Guizhou Province, the diel cycles of geochemistry of their surface water were measured for three days and nights. The results indicate that: 1) the ion indices of the reservoir water did not exhibit obvious diel variations due to variable weather and hydrological conditions, whereas regular indices of water temperature, Dissolved Oxygen (DO), pH, and partial pressure of CO2 exhibited apparent diurnal fluctuations. Under the control of water-rock interactions and the effect of the coal-bearing bedrock, the water chemical type of the Yelanghu Reservoir is Ca-HCO3·SO4. 2) By calculating the thermodynamic parameters and analyzing the principal components, it is found that these parameters are controlled by temperature, biological effects, and human activities, as well as storage and discharge of the reservoir, of which their contribution rates are 21.66%, 17.28%, 14.08%, and 10.22%, respectively, indicating that the influencing factors of hydrochemistry of the reservoirs are multivariate. 3) During the study period, the variation ranges of the Yelanghu Reservoir water’s δD and δ 18O values were -60.61‰~-57.17‰ and -8.11‰~-8.85‰, respectively, and the mean values were -59.44‰ and -8.46‰, respectively. The δD and δ 18O values were smaller during the day and larger at night. During the day, the biological activity in the reservoir is primarily photosynthesis with weak respiration; whereas at night, it is primarily respiration, which consumes a large amount of O2 to obtain more light isotope 16O, thereby resulting in a decrease in DO concentration in the water at night and a negative 18O. However, a comparison of the d-excess value of the reservoir water with the local atmospheric precipitation shows that the d-excess value of the former (8.21‰) is significantly lower than that of the latter (9.64‰), indicating the main effect of unbalanced fractionation caused by evaporation over a long period of time.

Key words: surface lake water, water chemistry, stable isotopes of Hydrogen and Oxygen, diel variation, the Yelanghu Reservoir, Guizhou

中图分类号: 

  • P342