| Abstract: | The assessment of water resource responses to climate change is required in water resource
planning and management, protecting environmental quality, and managing watersheds. This study
modeled surface runoff and baseflow responses to variations in precipitation (0%, +-10%, and +-20%)
and temperature (0 C, +-1 C, and +-2 C) in 25 types of scenarios in the Lanhe Watershed (1140 km2),
which possesses the typical hydrological and meteorological characteristics of the Loess Plateau in
China. The study is based on the Soil and Water Assessment Tool (SWAT), which was calibrated and
validated using the coefficient of determination (R2), Nash-Suttcliffe (Ens), and Percent bias (PBIAS),
using the observed streamflow of Shangjingyou Station, a unique gauging station in the study area.
The model was calibrated with daily streamflow, from 1967 to 1996, and then validated from 1997
to 2011. R2, Ens, and PBIAS were 0.95 and 0.84, 0.78 and 0.72, and 0.6% and 9.1% in annual
and monthly calibration periods, 0.90 and 0.78, 0.74 and 0.67, and 22.1% and 18.8% in annual and
monthly validation periods, and the overall performance ratings was “satisfactory”. The assessment
indicates that surface runoff is likely to be more affected than baseflow when altering temperatures
and precipitation, and the noticeable changes of surface and baseflow are from June to September and
October to November, respectively. Results also indicate that surface runoff and baseflow are very
sensitive to the projected reduction in temperature, rather than to an increase of temperature, while
precipitation is a constant. In turn, when the temperature is a constant, the surface runoff is sensitive
to the projected increase in precipitation and the baseflow is sensitive to the decrease in precipitation. |