TY - JOUR
T1 - Developing a hydro-chemical model of Ise Bay watersheds and the evaluation of climate change impacts on discharge and nitrate-nitrogen loads
AU - Onishi, Takeo
AU - Yoshino, Jun
AU - Hiramatsu, Ken
AU - Somura, Hiroaki
N1 - Funding Information:
The funding support to conduct this work was provided by JSPS Kakenhi No. 25450499 and No. 18H01542, respectively.
Publisher Copyright:
© 2020, The Japanese Society of Limnology.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - The objective of this study was to develop a hydro-chemical model using the Soil and Water Assessment Tool (SWAT) and to evaluate the climate change impacts on discharge and nitrate-nitrogen loads from Ise Bay watersheds (the Kiso, Nagara, Ibi, and Shonai rivers). Using a regional climate model, through the dynamic downscaling approach, present and future climate data were generated at a 2 km spatial resolution. The pseudo-global warming downscaling approach under the A1B scenario was adopted for future climate prediction. Then, the optimized SWAT model, driven by the present and future climate data, was executed. The following results were obtained: (1) the significant increase of precipitation in May and June and decrease in August in the future climate scenario, and consequent discharge from the target watersheds also increased in May and June and decreased in August and September; (2) Due to the change in discharge, nitrate-nitrogen loads of the Kiso, Nagara, and Ibi rivers also increased in May and June and decreased in August and September; and (3) While nitrate-nitrogen load from deciduous forest tends to decrease, the one from evergreen forest tends to increase. The response of the model indicated the possibility of an increase in nitrogen uptake by deciduous forests.
AB - The objective of this study was to develop a hydro-chemical model using the Soil and Water Assessment Tool (SWAT) and to evaluate the climate change impacts on discharge and nitrate-nitrogen loads from Ise Bay watersheds (the Kiso, Nagara, Ibi, and Shonai rivers). Using a regional climate model, through the dynamic downscaling approach, present and future climate data were generated at a 2 km spatial resolution. The pseudo-global warming downscaling approach under the A1B scenario was adopted for future climate prediction. Then, the optimized SWAT model, driven by the present and future climate data, was executed. The following results were obtained: (1) the significant increase of precipitation in May and June and decrease in August in the future climate scenario, and consequent discharge from the target watersheds also increased in May and June and decreased in August and September; (2) Due to the change in discharge, nitrate-nitrogen loads of the Kiso, Nagara, and Ibi rivers also increased in May and June and decreased in August and September; and (3) While nitrate-nitrogen load from deciduous forest tends to decrease, the one from evergreen forest tends to increase. The response of the model indicated the possibility of an increase in nitrogen uptake by deciduous forests.
KW - Climate change
KW - Ise bay
KW - Nitrate load
KW - SWAT
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U2 - 10.1007/s10201-020-00622-2
DO - 10.1007/s10201-020-00622-2
M3 - Article
AN - SCOPUS:85085108984
VL - 21
SP - 465
EP - 486
JO - Limnology
JF - Limnology
SN - 1439-8621
IS - 3
ER -