[Shallow Groundwater Around Plateau Lakesï¼ Spatiotemporal Distributions of Dissolved Carbon and Its Driving Factors].
Huan Jing Ke Xue
; 45(8): 4589-4599, 2024 Aug 08.
Article
em Zh
| MEDLINE
| ID: mdl-39168678
ABSTRACT
Dissolved carbon in groundwater plays an important role in carbon cycling and ecological function maintenance, and its concentration level affects the migration and transformation of pollutants in groundwater. To understand the spatiotemporal variation characteristics of dissolved carbon and its driving factors in shallow groundwater around plateau lakes, variations in the concentrations of dissolved organic carbon ï¼DOCï¼, inorganic carbon ï¼DICï¼, and total carbon ï¼DTCï¼ and their driving factors in shallow groundwater ï¼n = 404ï¼ around eight plateau lakes were analyzed. The results indicated that the average values of ρï¼DOCï¼, ρï¼DICï¼, and ρï¼DTCï¼ in shallow groundwater around plateau lakes were 8.23, 49.01, and 57.84 mg·L-1, respectively, with the ρï¼DOCï¼ in 79.0% of shallow groundwater samples exceeding 5 mg·L-1. There were no significant differences in the DOC, DIC, and DTC concentrations between rainy and dry seasons, whereas the change in dissolved carbon concentrations in shallow groundwater were strongly affected by the intensity of agricultural intensification and the depth of groundwater tableï¼ the DOC, DIC, and DTC concentrations in shallow groundwater from facility agricultural regions ï¼SFARï¼, cropland fallow agricultural regions ï¼CFARï¼, and intensive agricultural regions with deeper groundwater tables ï¼DIARï¼ were significantly reduced by 25.8% - 56.6%, 14.0% - 32.9%, and 16.6% - 36.7%, respectively, compared with those in intensive agricultural regions with shallower groundwater tables ï¼SIARï¼. Additionally, the dissolved carbon concentrations in shallow groundwater from DIAR were significantly lower than those of SFAR and CFAR. RDA revealed that physicochemical factors in water and soil significantly explained the changes in the dissolved carbon concentrations. Moreover, the dissolved carbon concentrations in shallow groundwater around Yilong Lake were significantly higher than those of other lakes, whereas that of Chenghai Lake was significantly lower than that of other lakes. Our study highlights that agricultural intensification intensity and groundwater table depth jointly drove the variations in dissolved carbon concentrations in shallow groundwater around plateau lakes. The study results are expected to provide a scientific basis for understanding the carbon cycle in plateau lake areas with underground runoff flowing into lakes and evaluating the attenuation of pollutants by dissolved carbon in shallow groundwater.
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MEDLINE
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Zh
Ano de publicação:
2024
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Article