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Tytuł:
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Coupled hydrological and biogeochemical modelling of nitrogen transport in the karst critical zone.
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Autorzy:
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Zhang Z; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China; School of Geosciences, University of Aberdeen, Aberdeen AB24 3UF, United Kingdom.
Chen X; Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China. Electronic address: xi_.
Cheng Q; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
Li S; Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
Yue F; Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China; School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
Peng T; Institute of Geochemistry Chinese Academy of Sciences, Guiyang 550081, China.
Waldron S; School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
Oliver DM; Biological & Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
Soulsby C; School of Geosciences, University of Aberdeen, Aberdeen AB24 3UF, United Kingdom.
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Źródło:
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The Science of the total environment [Sci Total Environ] 2020 Aug 25; Vol. 732, pp. 138902. Date of Electronic Publication: 2020 May 06.
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Typ publikacji:
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Journal Article
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Język:
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English
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Imprint Name(s):
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Original Publication: Amsterdam, Elsevier.
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Contributed Indexing:
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Keywords: Distributed water-N model; Karst critical zone; Nitrogen transport; Tracer-aided
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Entry Date(s):
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Date Created: 20200522 Date Completed: 20200612 Latest Revision: 20200612
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Update Code:
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20240105
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DOI:
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10.1016/j.scitotenv.2020.138902
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PMID:
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32438160
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Transport of nitrogen (N) in karst areas is more complex than in non-karst areas due to marked heterogeneity of hydrodynamic behaviour in the karst critical zone. Here, we present a novel, distributed, coupled hydrological-biogeochemical model that can simulate water and nitrogen transport in the critical zone of karst catchments. This new model was calibrated using integrated hydrometric, water stable isotope, and nitrogen-N concentration data at the outflow of Houzhai catchment in Guizhou province of Southwest China. Hydrological dynamics appears to control N load from the study catchment. Combining flow discharge and water stable isotopes significantly constrained model parameterisation and mitigate the equifinality effects of parameters on the simulated results. Karst geomorphology and land use have functional effects on spatiotemporal variations of hydrological processes and nitrogen transport. In the study catchment, agricultural fertilizer was the largest input source of N, accounting for 86% of the total. Plant uptake consumed about 45% of inputs, primarily in the low-lying valley bottom areas and the plain covered by relatively thick soils. Thus, a large amount of N released from soil reservoirs to the epikarst (via fractures or sinkholes) is then exported to the underground channel in the limestone area to the south. This N draining into groundwater could lead to extensive, potentially long-term contamination of the karst system. Therefore, improving the efficiency of fertilization and agricultural management in valleys/depressions is an urgent need to reduce N losses and contamination risk.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
