Increases in the seaward river flux of nutrients driven by human migration and land-use changes in the tide-influenced delta

Copyright © 2020 Elsevier B.V. All rights reserved..

Most large megacities are located on areas adjacent to tide-influenced deltas. However, contribution of megacities to seaward nutrient fluxes in tide-influenced deltas are poorly quantified in regional and global levels. We analyzed nutrient concentrations and water current data for a large and tide-influenced delta, the Changjiang (Yangtze River) since 1980. Concentrations, species ratios and fluxes of nutrients in tide-influenced delta has been found to differ dramatically from those at upstream. Over the period 2004 to 2015, the seaward nutrient fluxes of dissolved inorganic nitrogen and dissolved silica increased by 5%-10%, but dissolved inorganic phosphorus increased by 15%-20%, in the tide-influenced delta of the Changjiang. Consequently, the DIP/DIN decreases by 11% and DIP/DSi increases by 14% at the river mouth relative to those farther upstream the tidal limit. The legacy and/or recycled contribution accounts for 10%-30% of this increased nutrient flux, hence additional sources are predominantly those involving anthropogenic land-use changes. These findings have implications not only for the Changjiang but also for other riverine systems with respect to management strategy. Nutrient dynamics in tide-influenced deltas near urban areas should receive increased research and policy attention. By not considering nutrient sources in tide-influenced deltas, knowledge of the seaward fluxes and species ratios of nutrients from land sources is incomplete and can be biased, to the point that assessments of their impacts on adjacent marine environments may be inaccurate and mitigation policies therefore ineffective.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:761

Enthalten in:

The Science of the total environment - 761(2021) vom: 20. März, Seite 144501

Sprache:

Englisch

Beteiligte Personen:

Zhang, Jing [VerfasserIn]
Du, Ya Nan [VerfasserIn]
Zhang, Guo Sen [VerfasserIn]
Chang, Yan [VerfasserIn]
Zhou, Ying Chun [VerfasserIn]
Zhang, Zai Feng [VerfasserIn]
Wu, Ying [VerfasserIn]
Chen, Jia Wei [VerfasserIn]
Zhang, An Yu [VerfasserIn]
Zhu, Zhuo Yi [VerfasserIn]
Liu, Su Mei [VerfasserIn]

Links:

Volltext

Themen:

Changjiang
Human dimensions
Journal Article
Land-use changes
Megacities in the tide-influenced delta
Nutrient species ratio
Nutrients
Seaward nutrient fluxes

Anmerkungen:

Date Completed 21.01.2021

Date Revised 21.01.2021

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.scitotenv.2020.144501

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM319244598