Climatic and anthropogenic regulation of carbon transport and transformation in a karst river-reservoir system

Wang, Wan-Fa; Li, Si-Liang; Zhong, Jun; Maberly, Stephen C. ORCID: https://orcid.org/0000-0003-3541-5903; Li, Cai; Wang, Fu-Shun; Xiao, Hua-Yun; Liu, Cong-Qiang. 2020 Climatic and anthropogenic regulation of carbon transport and transformation in a karst river-reservoir system. Science of the Total Environment, 707, 135628. https://doi.org/10.1016/j.scitotenv.2019.135628

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Official URL: http://dx.doi.org/10.1016/j.scitotenv.2019.135628

Abstract/Summary

The effect of dams on dissolved inorganic carbon (DIC) transport and riverine ecosystems is unclear in karst cascade reservoirs. Here, we analyzed water samples from a karst river system with seven cascade reservoirs along the Wujiang River, southwestern China, during one hydrological year. From upstream to downstream, the average concentration of DIC increased from 2.2 to 2.6 mmol/L and its carbon isotope composition (δ13CDIC) decreased from −8.0 to −10‰. Meanwhile, the air temperature (Ta) increased from 20.3 °C to 26.7 °C and 10 °C to 13.7 °C in the warm and cold seasons, respectively. The results suggest that a cascade of dams has a stronger effect on DIC dynamics and retention than a single dam. The good correlation between Ta/HRT (hydraulic retention time) and Δ[DIC] as well as Δ[δ13CDIC] mean that Ta and HRT affected the magnitude of the damming effect by altering changes in concentration of DIC and δ13CDIC in the reservoir compared to the inflowing water. In particular, daily regulated reservoirs with short retention times acted more like river corridors and had a smaller effect on carbon dynamics, so modulating retention time might be used reduce the effect of dams on the riverine ecosystem.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.scitotenv.2019.135628
UKCEH and CEH Sections/Science Areas:	Water Resources (Science Area 2017-)
ISSN:	0048-9697
Additional Keywords:	dissolved inorganic carbon, carbon isotope, damming effect, cascade reservoirs, hydraulic retention time
NORA Subject Terms:	Ecology and Environment
Date made live:	23 Jan 2020 10:43 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/526569

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.scitotenv.2019.135628

UKCEH and CEH Sections/Science Areas:

Water Resources (Science Area 2017-)

ISSN:

0048-9697

Additional Keywords:

dissolved inorganic carbon, carbon isotope, damming effect, cascade reservoirs, hydraulic retention time

NORA Subject Terms:

Ecology and Environment