Arid Zone Research ›› 2022, Vol. 39 ›› Issue (5): 1543-1554.doi: 10.13866/j.azr.2022.05.19

• Land and Water Resources • Previous Articles     Next Articles

Interaction between surface water and groundwater and hydrochemical characteristics in the typical watersheds of the Qaidam Basin

YANG Haijiao1(),WEI Jiahua1,2(),REN Qianhui1   

  1. 1. State Key Laboratory of Plateau Ecology and Agriculture, Key Laboratory of Water Ecology Remediation and Protection at Headwater Regions of Big Rivers, Ministry of Water Resources, School of Water Resources and Electric Power, Laboratory of Ecological Protection and High Quality Development in the Upper Yellow River, Qinghai Province, Qinghai University, Xining 810016, Qinghai, China
    2. State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China
  • Received:2022-03-17 Revised:2022-05-27 Online:2022-09-15 Published:2022-10-25
  • Contact: Jiahua WEI E-mail:yyeezzii@163.com;weijiahua@tsinghua.edu.cn

Abstract:

The Qaidam Basin is a typical arid inland area in China. Recognizing the interaction between surface water (SW) and groundwater (GW), characteristics of water chemistry, and change law along the river in the basin is significant for developing and utilizing regional water resources and ecological protection laws. Hydrochemical and statistical analysis methods were used to study the SW-GW interactions, with the hydrochemical characteristics and differences being analyzed based on field investigation and analysis. According to the controlling effect of geological structure, strata, and landform on the hydraulic connection, the SW-GW interactions are divided into the following types: bedrock barrier + lithology control, lithology control + hydrometeorological influence, and lithology control. The hydrochemical types change from Ca to Na or Mg and from bicarbonate to chloride ion from the mountainous area to the tail area. The changing trends of the hydrochemical influence mechanism along the flow paths gradually change from water-rock interaction to evaporation-precipitation. The transformation of the SW-GW interaction in the inter-mountain valley and front of the alluvial-proluvial fan causes a local reversal of the changing law of hydrochemical characteristics along the river that are influenced by a bedrock barrier and lithology control. This is due to the lithology differences of aquifer, Na+, Cl-, and SO42- that are dominant in SW and GW in the south. Ca2+ and HCO3- are dominant in the north and east, and the F- concentration in the north is higher compared to other watersheds.

Key words: Qaidam Basin, interaction between surface water and groundwater, hydrochemical characteristics