Groundwater Plays an Important Role in Controlling Riverine Dissolved Organic Matter in a Cold Alpine Catchment, the Qinghai–Tibet Plateau

Abstract

The permafrost region possesses the largest terrestrial soil carbon pool, which is roughly twice as large as the atmospheric carbon pool (Schuur et al., 2015;Tarnocai et al., 2009). Dissolved organic carbon (DOC) has been used to quantify dissolved organic matter (DOM) since it represents the primary constituent of DOM (∼67%) (Bolan et al., 2011). A large amount of stored soil carbon becomes microbially and hydrologically available under

Modeling Dissolved Organic Carbon Dynamics in an Alpine Catchment Incorporating the Mountain‐Front Recharge

“…According to our simulations, the annual DOC export of the Hulugou catchment was approximately 5,412 ± 1,198 kg (Figure 5d), DOC export during summer accounted for 78% of the annual total, closely matching the 68% of annual DOC export from June to September reported by Hu et al. (2023). The simulated DOC export (0.23 ± 0.05 g m −2 yr −1 ) is consistent with values reported for other catchments on the Qinghai‐Tibet Plateau (0.18–0.41 g m −2 yr −1 ; Qu et al., 2017; Gao et al., 2019).…”

Modeling Dissolved Organic Carbon Dynamics in an Alpine Catchment Incorporating the Mountain‐Front Recharge

“…According to our simulations, the annual DOC export of the Hulugou catchment was approximately 5,412 ± 1,198 kg (Figure 5d), DOC export during summer accounted for 78% of the annual total, closely matching the 68% of annual DOC export from June to September reported by Hu et al. (2023). The simulated DOC export (0.23 ± 0.05 g m −2 yr −1 ) is consistent with values reported for other catchments on the Qinghai‐Tibet Plateau (0.18–0.41 g m −2 yr −1 ; Qu et al., 2017; Gao et al., 2019).…”

Freeze–Thaw Controls on Dissolved Organic Carbon Export: A Numerical Investigation of Hydrological Mechanisms in a Hillslope

“…Simulated results indicate a positive correlation between DOC flux and groundwater discharge, consistent with field observations from both Arctic regions and the QTP (Amon et al., 2012; Gao et al., 2019; Hu et al., 2023; Raymond et al., 2007; Sun et al., 2021; X. Wang et al., 2020; Zhu et al., 2020). Notably, the simulated decoupled peaks—highest DOC flux in September (thawed period) yet peak concentration in April (thawing period) (Figures 4 and 6c)—align with patterns observed at the Hulugou catchment outlet (Hu et al., 2023; Sun et al., 2021).…”

“…Simulated results indicate a positive correlation between DOC flux and groundwater discharge, consistent with field observations from both Arctic regions and the QTP (Amon et al, 2012;Gao et al, 2019;Hu et al, 2023;Raymond et al, 2007;Sun et al, 2021;X. Wang et al, 2020;Zhu et al, 2020).…”

Unraveling the Coupled Dynamics between DOM Transformation and Arsenic Mobilization in Aquifer Systems during Microbial Sulfate Reduction: Evidence from Sediment Incubation Experiment

“…Our findings align partially with previous observations in arsenic-contaminated aquifer systems [21], particularly highlighting the presence of endogenous humic-like DOM components that could be conducive to As mobilization under microbial sulfate reduction conditions. Moreover, the observed DOM transformation and predominant components after prolonged incubation align with earlier findings in groundwater from the Niyaqu catchment [53] and a permafrost zone on the Tibetan Plateau [54]. Therefore, the present novel insights could provide evidence for the biogeochemical processes controlling DOM transformation in alpine and cold aquifer systems, and they can also improve our understanding of co-evolution between DOM transformation and As mobilization in As-rich aquifer systems worldwide.…”

Modeling Dissolved Organic Carbon Dynamics in an Alpine Catchment Incorporating the Mountain‐Front Recharge

“…According to our simulations, the annual DOC export of the Hulugou catchment was approximately 5,412 ± 1,198 kg (Figure 5d), DOC export during summer accounted for 78% of the annual total, closely matching the 68% of annual DOC export from June to September reported by Hu et al. (2023). The simulated DOC export (0.23 ± 0.05 g m −2 yr −1 ) is consistent with values reported for other catchments on the Qinghai‐Tibet Plateau (0.18–0.41 g m −2 yr −1 ; Qu et al., 2017; Gao et al., 2019).…”

Freeze–Thaw Controls on Dissolved Organic Carbon Export: A Numerical Investigation of Hydrological Mechanisms in a Hillslope

“…Simulated results indicate a positive correlation between DOC flux and groundwater discharge, consistent with field observations from both Arctic regions and the QTP (Amon et al., 2012; Gao et al., 2019; Hu et al., 2023; Raymond et al., 2007; Sun et al., 2021; X. Wang et al., 2020; Zhu et al., 2020). Notably, the simulated decoupled peaks—highest DOC flux in September (thawed period) yet peak concentration in April (thawing period) (Figures 4 and 6c)—align with patterns observed at the Hulugou catchment outlet (Hu et al., 2023; Sun et al., 2021).…”

“…Simulated results indicate a positive correlation between DOC flux and groundwater discharge, consistent with field observations from both Arctic regions and the QTP (Amon et al, 2012;Gao et al, 2019;Hu et al, 2023;Raymond et al, 2007;Sun et al, 2021;X. Wang et al, 2020;Zhu et al, 2020).…”

Unraveling the Coupled Dynamics between DOM Transformation and Arsenic Mobilization in Aquifer Systems during Microbial Sulfate Reduction: Evidence from Sediment Incubation Experiment

“…Our findings align partially with previous observations in arsenic-contaminated aquifer systems [21], particularly highlighting the presence of endogenous humic-like DOM components that could be conducive to As mobilization under microbial sulfate reduction conditions. Moreover, the observed DOM transformation and predominant components after prolonged incubation align with earlier findings in groundwater from the Niyaqu catchment [53] and a permafrost zone on the Tibetan Plateau [54]. Therefore, the present novel insights could provide evidence for the biogeochemical processes controlling DOM transformation in alpine and cold aquifer systems, and they can also improve our understanding of co-evolution between DOM transformation and As mobilization in As-rich aquifer systems worldwide.…”

Modeling Dissolved Organic Carbon Dynamics in an Alpine Catchment Incorporating the Mountain‐Front Recharge

“…According to our simulations, the annual DOC export of the Hulugou catchment was approximately 5,412 ± 1,198 kg (Figure 5d), DOC export during summer accounted for 78% of the annual total, closely matching the 68% of annual DOC export from June to September reported by Hu et al. (2023). The simulated DOC export (0.23 ± 0.05 g m −2 yr −1 ) is consistent with values reported for other catchments on the Qinghai‐Tibet Plateau (0.18–0.41 g m −2 yr −1 ; Qu et al., 2017; Gao et al., 2019).…”

Freeze–Thaw Controls on Dissolved Organic Carbon Export: A Numerical Investigation of Hydrological Mechanisms in a Hillslope

“…Simulated results indicate a positive correlation between DOC flux and groundwater discharge, consistent with field observations from both Arctic regions and the QTP (Amon et al., 2012; Gao et al., 2019; Hu et al., 2023; Raymond et al., 2007; Sun et al., 2021; X. Wang et al., 2020; Zhu et al., 2020). Notably, the simulated decoupled peaks—highest DOC flux in September (thawed period) yet peak concentration in April (thawing period) (Figures 4 and 6c)—align with patterns observed at the Hulugou catchment outlet (Hu et al., 2023; Sun et al., 2021).…”

“…Simulated results indicate a positive correlation between DOC flux and groundwater discharge, consistent with field observations from both Arctic regions and the QTP (Amon et al, 2012;Gao et al, 2019;Hu et al, 2023;Raymond et al, 2007;Sun et al, 2021;X. Wang et al, 2020;Zhu et al, 2020).…”

Unraveling the Coupled Dynamics between DOM Transformation and Arsenic Mobilization in Aquifer Systems during Microbial Sulfate Reduction: Evidence from Sediment Incubation Experiment

“…Our findings align partially with previous observations in arsenic-contaminated aquifer systems [21], particularly highlighting the presence of endogenous humic-like DOM components that could be conducive to As mobilization under microbial sulfate reduction conditions. Moreover, the observed DOM transformation and predominant components after prolonged incubation align with earlier findings in groundwater from the Niyaqu catchment [53] and a permafrost zone on the Tibetan Plateau [54]. Therefore, the present novel insights could provide evidence for the biogeochemical processes controlling DOM transformation in alpine and cold aquifer systems, and they can also improve our understanding of co-evolution between DOM transformation and As mobilization in As-rich aquifer systems worldwide.…”