Hydrologic Simulations In Two Subcatchments Of The Boulder Creek Watershed
Zhang, Qinghuan 1 ; Williams, Mark 2 ; Cowie, Rory 3
1 Geography & INSTAAR, University of ÃÛÌÇÖ±²¥ Boulder
2 Geography & INSTAAR, University of ÃÛÌÇÖ±²¥ Boulder
3 Geography & INSTAAR, University of ÃÛÌÇÖ±²¥ Boulder
Hydrologic modeling is necessary in predicting discharge, especially in mountainous areas where the measurements are hard to realize. The Variable Infiltration Capacity (VIC) model was applied to two sub-catchments of the Boulder Creek watershed, Como Creek and Fourmile Creek watersheds, and generated good results. The former catchment straddles subalpine and lower alpine zones, and has barely been influenced by human activities; the latter catchment is located in a montane zone, and has extensive logging and homes. The results showed that surface discharge in both of these two catchments was dominated by baseflow. However, discharge after the year 2010 in Fourmile Creek watershed is more irregular, which may be impacted by the forest fire. The 2010 Fourmile Canyon Fire influenced vegetation and soil conditions, indicating that using the same parameters before the fire can not give reliable results. Another reason comes from climate forcing data. The climate data before the year 2010 was from Maurer's dataset (Maurer et al., 2002), whereas the climate forcing data after the year 2010 was collected from Western Regional Climate Center, Boulder Station. The predicted discharge from the year 1990 to 1995, and 2011 to 2014 were shown in Figures 1 and 2. The unpredictable discharge after the year 2010 means that geological transformations are as important as climate forcing when using the VIC model.