土壤2025，Vol.57Issue(2)：282-289,8.DOI:10.13758/j.cnki.tr.2025.02.005
三峡库区消落带淹水后土-水界面磷扩散特征及释放风险
Characteristics of Phosphorus Diffusion at Soil-water Interface After Inundation in Water-level Fluctuation Zone in Three Gorges Reservoir
摘要
Abstract
The process of phosphorus(P)exchange at soil-water interface remains unclear following flooding in the Three Gorges Reservoir's water-level fluctuation zone(WLFZ),which could lead to an increase in P load in the water.In this study,diffusion gradients in the films(DGT)and high-resolution dialysis(HR-Peeper)were employed to simultaneously measure DGT-labile P and Fe(DGT P and Fe)and dissolved P and Fe in WLFZ's soils after inundation.The results showed that the average concentrations of DGT P and Fe,dissolved P and Fe were 0.022,0.050,0.151 and 1.515 mg/L,respectively.The peaks of dissolved P and Fe at both 150 m and 160 m elevations and DGT P and Fe at 150 m elevation occurred in the middle and deep layers,while the peaks of DGT P and Fe at 160 m elevation occurred at the soil-water interface.Following flooding,phosphate release at 150 m was mostly driven by the reduction of Fe oxides,which increased P concentration in the water.However,plant root limitation,soil heterogeneous structure,and overlaying water P infiltration stress all had an impact on P diffusion at 160 m elevation.The capacity of available solid P pool to replenish solute P in pore water were 0.291 and 0.286,which was in the medium level at 150 and 160 m elevations,respectively.The average diffusion fluxes of P at the soil-water interface at 150 m and 160 m elevations were 5.60×10-6 and-5.68×10-6 mg/(cm2·d),respectively(positive values indicate the release of P from the soil),which were significantly lower than the results of sediments in previous studies.In conclusion,the current risk of soil P release after inundation in the tributary's bay WLFZ in the Three Gorges Reservoir is notably low,which is related to the input of P in the overlying water.关键词
消落带/土-水界面/薄膜梯度扩散技术(DGT)/高分辨率孔隙水采样装置(HR-Peeper)/磷扩散特征/释放风险Key words
Water-level fluctuation zone(WLFZ)/Soil-water interface/Diffusion gradient in thin films(DGT)/High-resolution dialysis(HR-Peeper)/Characteristics of phosphorus diffusion/Release risk分类
资源环境引用本文复制引用
张雪,朱波..三峡库区消落带淹水后土-水界面磷扩散特征及释放风险[J].土壤,2025,57(2):282-289,8.基金项目
国家自然科学基金重大项目(41430750)资助. （41430750）
