Assessing the impact of climate variability and human activities on streamflow variation
Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydro...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-04-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/20/1547/2016/hess-20-1547-2016.pdf |
| Summary: | Water resources in river systems have been changing under the impact of both
climate variability and human activities. Assessing the respective impact on
decadal streamflow variation is important for water resource management. By
using an elasticity-based method and calibrated TOPMODEL and VIC
hydrological models, we quantitatively isolated the relative contributions
that human activities and climate variability made to decadal streamflow
changes in the Jinghe basin, located in the northwest of China. This is an
important watershed of the Shaanxi province that supplies drinking water for a
population of over 6 million people. The results showed that the maximum
value of the moisture index (<i>E</i><sub>0</sub>∕<i>P</i>) was 1.91 and appeared in 1991–2000,
and the decreased speed of streamflow was higher since 1990 compared with
1960–1990. The average annual streamflow from 1990 to 2010 was reduced by
26.96 % compared with the multiyear average value (from 1960 to 2010).
The estimates of the impacts of climate variability and human activities on
streamflow decreases from the hydrological models were similar to those from
the elasticity-based method. The maximum contribution value of human
activities was 99 % when averaged over the three methods, and appeared
in 1981–1990 due to the effects of soil and water conservation measures and
irrigation water withdrawal. Climate variability made the greatest
contribution to streamflow reduction in 1991–2000, the values of which was
40.4 %. We emphasized various source of errors and uncertainties that may
occur in the hydrological model (parameter and structural uncertainty) and
elasticity-based method (model parameter) in climate change impact studies. |
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| ISSN: | 1027-5606 1607-7938 |