• APN
  • INPC
  • IET
  • UPMC
  • NUS
  • Yunnan
  • IRD

Thi Thao Ta, Si Hung Le, Hong Quan Trinh, Thi Nguyet Minh Luu, Anh Duc Trinh (2016).

Interpretation of anthropogenic impacts (agriculture and urbanization) on tropical deltaic river network through the spatio-temporal variation of stable (N, O) isotopes of NO- 3, Isotopes in Environmental and Health Studies, 52(4-5), pp. 487-497, http://dx.doi.org/10.1080/10256016.2016.1142987

For the first time, the dual isotope approach was applied to trace the sources of impacts and to identify the governing biogeochemical processes in a river network in the tropical deltaic region of the Red River (Vietnam). Our long term surveys concluded that water in this river network was severely impacted by anthropogenic activities. Analysis has shown strong spatio-temporal variation of nitrate isotopes; ranges of δ15N–NO3- and δ18O– NO3- were from -5 to 15 ‰ and from -10 to 10 ‰, respectively. Average values of δ15N–NO3- and δ18O–NO3- in the dry season, when fertilizer is applied, were 3.54 and 3.15 ‰, respectively. In the rainy season, the values changed to 6.41 and -2.23 ‰, respectively. Denitrification and biological assimilation were active throughout the year, but were especially enhanced during fertilization time. Mineralization of domestic organic matter and consequent nitrification of mineralized NH4+ were the dominant processes, particularly during the rainy period.
Login to download
Sign up