Temporal and spatial distribution of dissolved inorganic carbon in the rivers on the Tibetan Plateau
(2023) In Student thesis series INES NGEM01 20231Dept of Physical Geography and Ecosystem Science
- Abstract
- Dissolved inorganic carbon (DIC) is a pivotal component of the carbon cycle and is sensitive to environmental disturbances. In the context of the Tibetan Plateau, its spatial and temporal variations in DIC concentrations and flux have substantial implications for regional and global carbon cycles, which, however, remains poorly understood. This study harmonized a large database of riverine DIC observations and applied a machine-learning method, a random forest (RF) model, to quantify the DIC concentration and DIC fluxes across the exorheic rivers of the Tibetan Plateau. This study makes the first attempt of a DIC modeling capable of reproducing the magnitude of DIC concentration and fluxes, as well as its trend on a monthly scale. Results... (More)
- Dissolved inorganic carbon (DIC) is a pivotal component of the carbon cycle and is sensitive to environmental disturbances. In the context of the Tibetan Plateau, its spatial and temporal variations in DIC concentrations and flux have substantial implications for regional and global carbon cycles, which, however, remains poorly understood. This study harmonized a large database of riverine DIC observations and applied a machine-learning method, a random forest (RF) model, to quantify the DIC concentration and DIC fluxes across the exorheic rivers of the Tibetan Plateau. This study makes the first attempt of a DIC modeling capable of reproducing the magnitude of DIC concentration and fluxes, as well as its trend on a monthly scale. Results show that over the period 1979 – 2018, the average DIC concentration and DIC fluxes on the Tibetan Plateau is 19.50 mg/L, and 6.94 Tg/yr. Simultaneously, we found a significant increase in DIC concentration and DIC fluxes at a rate of 0.17 mg L-1 yr-1 and 0.048 Tg yr-2 on the Tibetan Plateau (P<0.01). DIC concentration generally decreases along the downstream direction while DIC fluxes shows the opposite pattern. Discharge dominates the spatial-temporal variability of DIC fluxes. Trends in DIC concentration are controlled by precipitation, temperature and discharge and spatial pattern of DIC concentration is also driven by slope and lithological conditions. Given the dominance of discharge in driving DIC flux, the increase in DIC flux is likely to continue under the projected increase in river discharge over China resulting from a future wetter climate. (Less)
- Popular Abstract
- Dissolved inorganic carbon (DIC) is an important component of the carbon cycle and is sensitive to environmental changes. In the context of the Tibetan Plateau, its spatial and temporal variations in DIC have substantial implications for regional and global carbon cycles, which, however, remains poorly understood. This study used a large database of riverine DIC observations and applied a machine-learning method, Random Forest model (a model based on a multitude of decision trees), to quantify the DIC concentration and DIC fluxes across the outflow rivers of the Tibetan Plateau. This study successfully modeled the monthly trends of DIC concentration and fluxes.
Results show that from 1979 to 2018, both DIC concentration and fluxes have... (More) - Dissolved inorganic carbon (DIC) is an important component of the carbon cycle and is sensitive to environmental changes. In the context of the Tibetan Plateau, its spatial and temporal variations in DIC have substantial implications for regional and global carbon cycles, which, however, remains poorly understood. This study used a large database of riverine DIC observations and applied a machine-learning method, Random Forest model (a model based on a multitude of decision trees), to quantify the DIC concentration and DIC fluxes across the outflow rivers of the Tibetan Plateau. This study successfully modeled the monthly trends of DIC concentration and fluxes.
Results show that from 1979 to 2018, both DIC concentration and fluxes have been increasing on the Tibetan Plateau. DIC concentration generally decreases along the downstream direction while DIC fluxes shows the opposite pattern. Discharge dominates the spatial-temporal variability of DIC fluxes. Trends in DIC concentration are controlled by precipitation, temperature and discharge and spatial pattern of DIC concentration is also driven by slope and rock types of the upper basin. Given the dominance of discharge in driving DIC flux, the increase in DIC flux is likely to continue under the projected increase in river discharge over China resulting from a future wetter climate. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9130818
- author
- Chen, Shan LU
- supervisor
-
- Yanzi Yan LU
- Martin Berggren LU
- organization
- course
- NGEM01 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Tibetan Plateau, dissolved inorganic carbon, concentration, flux, discharge
- publication/series
- Student thesis series INES
- report number
- 617
- language
- English
- id
- 9130818
- date added to LUP
- 2023-06-28 21:53:55
- date last changed
- 2024-04-29 10:34:07
@misc{9130818,
abstract = {{Dissolved inorganic carbon (DIC) is a pivotal component of the carbon cycle and is sensitive to environmental disturbances. In the context of the Tibetan Plateau, its spatial and temporal variations in DIC concentrations and flux have substantial implications for regional and global carbon cycles, which, however, remains poorly understood. This study harmonized a large database of riverine DIC observations and applied a machine-learning method, a random forest (RF) model, to quantify the DIC concentration and DIC fluxes across the exorheic rivers of the Tibetan Plateau. This study makes the first attempt of a DIC modeling capable of reproducing the magnitude of DIC concentration and fluxes, as well as its trend on a monthly scale. Results show that over the period 1979 – 2018, the average DIC concentration and DIC fluxes on the Tibetan Plateau is 19.50 mg/L, and 6.94 Tg/yr. Simultaneously, we found a significant increase in DIC concentration and DIC fluxes at a rate of 0.17 mg L-1 yr-1 and 0.048 Tg yr-2 on the Tibetan Plateau (P<0.01). DIC concentration generally decreases along the downstream direction while DIC fluxes shows the opposite pattern. Discharge dominates the spatial-temporal variability of DIC fluxes. Trends in DIC concentration are controlled by precipitation, temperature and discharge and spatial pattern of DIC concentration is also driven by slope and lithological conditions. Given the dominance of discharge in driving DIC flux, the increase in DIC flux is likely to continue under the projected increase in river discharge over China resulting from a future wetter climate.}},
author = {{Chen, Shan}},
language = {{eng}},
note = {{Student Paper}},
series = {{Student thesis series INES}},
title = {{Temporal and spatial distribution of dissolved inorganic carbon in the rivers on the Tibetan Plateau}},
year = {{2023}},
}