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Flow prediction accuracy given DEM resolution. Model accuracy for snow-rain transition watersheds was more sensitive to DEM resolution than for snow -dominated watersheds.
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Flow prediction accuracy given DEM resolution • Model accuracy for snow-rain transition watersheds was more sensitive to DEM resolution than for snow-dominated watersheds. • Model accuracy for watersheds with steep slopes was more sensitive to DEM resolution than for watersheds with mild slopes. • Model accuracy in general is higher for snow dominated watersheds. • K.Son, Tague. C and , Hunsaker, C.T, (in prep) Effect of spatial resolution of DEM on ecohydrologic predictions and its sensitivity to climate variability in Sierra mountain catchments, Water resources Research.
Soil parameter uncertainty effectvs. climate warming effect TMS (P301) SMS (B203) • Soil parameter uncertainty effect was larger than climate warming effect. • The climate warming effect was larger in the wetter climate conditions • K. Son and Tague, C. (in prep) Importance of soil parameter uncertainty in assessing climate change projections in small two Sierra watersheds, Water resource research
What are strategic soil moisture sampling design to represent the impact of climate variability on soil moisture and vegetation water use in snow-dominated watersheds? Snow, Soil moisture, Transpiration, ET and Streamflow Calibrated RHESSYs model Generated Spatial and temporal values of snow, soil moisture and transpiration Hydrologic Similarity indices (HSI) Snow Transpiration Soil moisture Clustering analysis (PAM algorithm) Finding Clusters and Medoids Sampling Recalibrated model Hydrologic Similarity indices (HSI) mean and inter-annual variation (expressed as coefficient of variation, CV) of five indicators (1) Day of water year that snow melts completely (2) Number of days that root-zone soil moisture is fully saturated (3) Number of days that root-zone soil moisture declines to 70% of saturation (4) Number of days that root-zone soil moisture declines to 50% of saturation (5) Day of water year that transpiration declines to 50% of its peak growing season value
Validation of sampling design C2 C5 C3 C6 C1 C4 • Combining all indices represent elevation difference and the flow drainage pattern. • Model-based clusters reproduced general spatial pattern of observed soil moisture. • K.Son, Tague, C. (in prep) Strategic sampling microclimate, soil moisture and sapflux for improving ecohydrological predictions of the Sierra Mountain watersheds., Hydrological Processes
With a warmer climate (+3°C) and no change in precipitation – we get increased water demand (Forest ET/NPP should stay the same orincrease) – but also a shift in timing (ET/NPP might go down because more winter P is lost as runoff ) Control on ET (regression) Change in ET (warming) (mm/yr) Precip PkSwe Interaction Soil parameter uncertainty changes strength of relationships - but not conclusions about importance of precipitation, timing, and their interaction For all patches, all years, change in ET Note that the effect of timing occurs across all P, but is greater in wetter years, but also biggest increases occur in the wettest years Tague, C., and H. Peng (2013), The sensitivity of forest water use to the timing of precipitation and snowmelt recharge in the California Sierra: Implications for a warming climate, J. Geophys. Res. Biogeosci., 118, doi:10.1002/jgrg.20073