Hydrological connectivity affects nitrogen migration and retention in the land‒river continuum

Wang，Yao1,2; Lin，Jingjie1,2; Wang，Fenfang1,2; Tian，Qing1,2; Zheng，Yi3; Chen，Nengwang1,2

2023-01-15

10.1016/j.jenvman.2022.116816

JOURNAL OF ENVIRONMENTAL MANAGEMENT   Impact Factor & Quartile

0301-4797

1095-8630

Land use change and excessive nitrogen (N) loading threaten the health of receiving water bodies worldwide. However, the role of hydrological connectivity in linking watershed land use, N biogeochemistry and river water quality remain unclear. In this study, we investigated 15 subwatersheds in the Jiulong River watershed (southeastern China) during a dry baseflow period in 2018, combined with 3‒year (2017–2019) nutrient monitoring in 5 subwatersheds to explore river N dynamics (dissolved nutrients, dissolved gases and functional genes) and their controlling factors at three hydrological connectivity scales, i.e., watershed, hydrologically sensitive areas (HSAs) and riparian zone. The results show that land use at HSAs (less than 20% of watershed area) and watershed scales contributed similarly to river N variation, indicating that HSAs are hotspots for transporting land N into river channels. In particular, the agricultural land was the main factor affecting river nitrate and nitrous oxide (NO) concentrations, while the built–up land significantly affected river ammonium and nitrite. At the riparian zone scale, soils and sediments substantially influenced river N retention processes (i.e., nitrification and denitrification). Management and protection measures targeting HSAs and riparian zones are expected to efficiently reduce river N loading and improve water quality.

Hydrologically sensitive areas Land use Nitrification and denitrification Water quality Watershed management

SCI

English

Others

National Natural Science Foundation of China[51961125203];

Environmental Sciences & Ecology

Environmental Sciences

WOS:000892195500001

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD

ENVIRONMENT/ECOLOGY

2-s2.0-85142194685

Scopus

1.Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies,College of the Environment and Ecology,Xiamen University,Xiamen,China
2.State Key Laboratory of Marine Environmental Science,Xiamen University,Xiamen,China
3.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,China

Wang，Yao,Lin，Jingjie,Wang，Fenfang,等. Hydrological connectivity affects nitrogen migration and retention in the land‒river continuum[J]. JOURNAL OF ENVIRONMENTAL MANAGEMENT,2023,326.

Wang，Yao,Lin，Jingjie,Wang，Fenfang,Tian，Qing,Zheng，Yi,&Chen，Nengwang.(2023).Hydrological connectivity affects nitrogen migration and retention in the land‒river continuum.JOURNAL OF ENVIRONMENTAL MANAGEMENT,326.

Wang，Yao,et al."Hydrological connectivity affects nitrogen migration and retention in the land‒river continuum".JOURNAL OF ENVIRONMENTAL MANAGEMENT 326(2023).