Arid Zone Research ›› 2020, Vol. 37 ›› Issue (5): 1215-1222.doi: 10.13866/j.azr.2020.05.14

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Magnitude of groundwater evapotranspiration in the Badain Jaran Desert based on groundwater dynamics method and empirical model:A case study of the Sumujilin Lake Area

ZHANG Wen-jia, WANG Nai-ang, YU Xin-ran, NIN Zhen-min, ZHAO Li-qiang   

  1. (College of Earth and Environmental Sciences, Center for Glacier and Desert Research, Lanzhou University, Lanzhou 730000, Gansu, China)
  • Received:2019-12-23 Revised:2020-03-26 Online:2020-09-15 Published:2020-12-16
  • Contact: 张文佳(1994-),女,硕士研究生,研究方向为气候变化与水循环. E-mail: wjzhang2017@lzu.edu.cn

Abstract: The Sumujilin Lake Area was taken as a study case to determine the contribution of evapotranspiration to groundwater drainage in the Badain Jaran Desert hinterland. Using high- resolution remote sensing image, digital elevation model (DEM), and field- measured groundwater depth, we extracted the ranges of lake water surface, different types of vegetation coverage areas, and groundwater depth hierarchic areas in the study area. Meanwhile, the evapotranspiration of vegetation coverage area and bare land wererespectively calculated on the basis of the groundwater dynamic method and the groundwater evapotranspiration empirical model. The results showed that the evapotranspiration from the Phragmites australis observation area is larger than that from the Nitraria tangutorum- Achnatherum splendens observation area during the same period. There are differences in the evapotranspiration patterns of the two types of observation areas. The former reaches the peak of the evapotranspiration rate during the middle stage of the growing season, whereas the latter reaches the peak during the early stage. Under the same atmospheric conditions, the total amount of groundwater evapotranspiration with vegetation cover in the Sumujilin Lake Area during the growing season is 16% to 18% more than that without vegetation coverage. Therefore, using only bare land groundwater evapotranspiration formulas or models to calculate the groundwater balance of the lake basin would produce large errors. Finally, the total amount of groundwater evapotranspiration in the Sumujilin Lake Area, including vegetation coverage and bare zone with shallow groundwater depth, accounts for 11.3% to 13.2% of the total groundwater drainage in the lake area, which proves that groundwater evapotranspiration is one of the key items of the water cycle of Badain Jaran Desert lakes and could not be negligible in the water balance studies.

Key words: groundwater evapotranspiration, extinction depth, riparian vegetation, groundwater dynamic method, groundwater drainage, Badain Jaran Desert