| Low streamflow statistics are critical to water resource management. At ungauged stream sites, low flow regional regression models are commonly used to estimate streamflow statistics. The objectives of this study are to (1) evaluate the sensitivity of low-flow regional regression models to the resolution of the digital elevation models (DEM) used to derive watershed characteristics and (2) examine the suitability of digital aquifer information for describing hydrogeology in these models. Watershed characteristics were derived for stream sites in Illinois, Kansas, and Georgia using 1 km and 85 m resolution DEMs. The Kansas and Illinois models performed better when constructed of watershed characteristics derived from the 85 m DEMs, but Georgia models performed better when the 1 km DEMs were used. Only the Georgia digital aquifer data, which describes the areal extent of major recharge areas, proved useful for describing low flows. |
