Issue |
E3S Web Conf.
Volume 98, 2019
16th International Symposium on Water-Rock Interaction (WRI-16) and 13th International Symposium on Applied Isotope Geochemistry (1st IAGC International Conference)
|
|
---|---|---|
Article Number | 12007 | |
Number of page(s) | 5 | |
Section | Applied Isotope Geochemistry | |
DOI | https://doi.org/10.1051/e3sconf/20199812007 | |
Published online | 07 June 2019 |
The role of unsaturated zone in estimating groundwater recharge in arid and semiarid areas as depicted by geochemical tracers
1
Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
2
College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
3
College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083, China
* Corresponding author: tmhuang@mail.iggcas.ac.cn
In arid and semiarid area, the recharge rate is relatively limited and the unsaturated zone (UZ) is commonly thick. The moisture in the UZ may represent the water infiltrating from precipitation during the past decades to thousands of years. Therefore, the multiple geochemical tracers in soil moisture, including Cl (chloride mass balance), 3H (tritium peak displacement), NO3, 2H, 18O, can be used to estimate diffuse recharge rate and related recharge characteristics. Based on 45 UZ profiles with maximum depth of 62 m in the Ordos Basin in NW China, a typical arid and semiarid area, we has used multiple geochemical tracers to study the following recharge informations: (1) reconstruction of groundwater recharge history, (2) determination of groundwater recharge mechanism, and (3) assessment of impact of vegetation changes on groundwater recharge. The results show that the soil texture (epically the shallow soil), vegetation and precipitation mainly control the recharge rate. This study also found that shallow groundwater in arid and semiarid areas is often not in equilibrium with near-surface boundary conditions. To estimate present recharge information, the UZ must be considered. The whole recharge process from precipitation to groundwater cannot be well understood unless the UZ have been included in arid and semiarid areas.
© The Authors, published by EDP Sciences, 2019
This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.