TY - JOUR
T1 - Assessing climate change effects on water balance in a monsoon watershed
AU - Ashu, Agbortoko Bate
AU - Lee, Sang Il
N1 - Publisher Copyright:
© 2020 by the authors.
PY - 2020/9
Y1 - 2020/9
N2 - Understanding the changes on future water resources resulting from climate variations will assist in developing effective management strategies for a river basin. Our area of interest is the Osan watershed in South Korea, where the summer monsoon contributes approximately 60-70% of the annual runoff and precipitation for the country. We determined the effects that future climatic changes have on this area. To accomplish this, we made use of global climate models (GCMs). A total of 10 GCMs were downscaled with the help of climate information production tools. Coupled with the GCMs and the Soil and Water Assessment (SWAT) model, three periods were used to assess these climate impacts. The baseline, mid-century (MC), and end-century (EC) periods include 1993-2018, 2046-2065, and 2081-2099, respectively. The entire process was performed using two scenarios (4.5 and 8.5) from the representative concentration pathways (RCPs). Some of the statistical metrics used for model calibration and validation were p-factor, r-factor, percent bias, root-mean-square error (RMSE), and Nash-Sutcliffe model efficiency. Their respective values were 0.88, 0.88, 8.3, 0.91, and 0.91 for calibration, and 1.16, 0.85, 7.9, 0.88, and 0.87 for validation. For the MC and EC periods under both scenarios, we projected an increase in temperature and precipitation of approximately 2-5 °C and 15-30%, respectively. A predicted rise in precipitation, surface flow, lateral flow, and water yield were noted for the month of June. Subsequently, a decline in July followed during the summer monsoon season. Summer monsoon rains will fluctuate more sharply, with heavy rainfall in June, lower rainfall in July, and more rain in the late summer, leading to the possibility of both flooding and drought within a given period. Annual precipitation, surface flow, lateral flow, and water yield will increase whereas evapotranspiration would decrease in both periods under both scenarios during the summer monsoon period, which will lead to wetter conditions in the future.
AB - Understanding the changes on future water resources resulting from climate variations will assist in developing effective management strategies for a river basin. Our area of interest is the Osan watershed in South Korea, where the summer monsoon contributes approximately 60-70% of the annual runoff and precipitation for the country. We determined the effects that future climatic changes have on this area. To accomplish this, we made use of global climate models (GCMs). A total of 10 GCMs were downscaled with the help of climate information production tools. Coupled with the GCMs and the Soil and Water Assessment (SWAT) model, three periods were used to assess these climate impacts. The baseline, mid-century (MC), and end-century (EC) periods include 1993-2018, 2046-2065, and 2081-2099, respectively. The entire process was performed using two scenarios (4.5 and 8.5) from the representative concentration pathways (RCPs). Some of the statistical metrics used for model calibration and validation were p-factor, r-factor, percent bias, root-mean-square error (RMSE), and Nash-Sutcliffe model efficiency. Their respective values were 0.88, 0.88, 8.3, 0.91, and 0.91 for calibration, and 1.16, 0.85, 7.9, 0.88, and 0.87 for validation. For the MC and EC periods under both scenarios, we projected an increase in temperature and precipitation of approximately 2-5 °C and 15-30%, respectively. A predicted rise in precipitation, surface flow, lateral flow, and water yield were noted for the month of June. Subsequently, a decline in July followed during the summer monsoon season. Summer monsoon rains will fluctuate more sharply, with heavy rainfall in June, lower rainfall in July, and more rain in the late summer, leading to the possibility of both flooding and drought within a given period. Annual precipitation, surface flow, lateral flow, and water yield will increase whereas evapotranspiration would decrease in both periods under both scenarios during the summer monsoon period, which will lead to wetter conditions in the future.
KW - Climate change
KW - GCMs
KW - Monsoon watershed
KW - SWAT model
KW - Water resources
UR - http://www.scopus.com/inward/record.url?scp=85092184097&partnerID=8YFLogxK
U2 - 10.3390/W12092564
DO - 10.3390/W12092564
M3 - Article
AN - SCOPUS:85092184097
SN - 2073-4441
VL - 12
JO - Water (Switzerland)
JF - Water (Switzerland)
IS - 9
M1 - 2564
ER -