HR: 1330h
AN: H42G-1153    [PDF]
TI: Hydrometric Analysis of the Panola Mountain Research Watershed, Georgia, USA: Linkage Among Rainfall, Watershed Wetness, and Stormflow
AU: * Peters, N E
EM: nepeters@usgs.gov
AF: USGS, 3039 Amwiler Rd., Atlanta, GA 30360-2824 United States
AU: Freer, J E
EM: j.freer@lancaster.ac.uk
AF: Lancaster University, Environmental Sciences, Lancaster, LA1 4YQ United Kingdom
AU: Aulenbach, B T
EM: btaulenb@usgs.gov
AF: USGS, 3039 Amwiler Rd., Atlanta, GA 30360-2824 United States
AB: Relations between stormflow characteristics and soil-moisture content, water-table elevation, and precipitation were evaluated for the 41-ha Panola Mountain Research Watershed (PMRW) for water years 1986 through 2001 to refine the conceptualization of streamflow generation. During the 16-year period, precipitation ($<$1% snowfall) averaged 1,220 mm and annual water yield averaged 30%, ranging from 16% to 50%. Rainfall was relatively uniform throughout the year. For 759 rainstorms, median stormflow (median duration of 33 h) water yield for all rainstorms was small (2.3%), ranging from 1.8% to 7.6%, with the highest median percentage occurring during the dormant wet winter season, when rainfall replenishes the soil-moisture deficit and recharges ground water. Runoff and stormflow were highly correlated with rainfall; the relation indicates that runoff is generally higher for comparable rainfall during the winter compared to the other seasons, which is consistent with higher moisture deficits and higher evapotranspiration in the other seasons. Stormflow water yield correlates best with storm-period maximum soil-moisture content and with storm-period maximum water-table elevation. Furthermore, the relations are linear above thresholds for the entire period and vary by season. For moderate to large rainstorms, relations among wetness parameters and stormflow water yield are better (less scatter) and more consistent when the watershed is seasonally wet than when it is dry. Soil-moisture content (minimum or maximum) is highly correlated among soil depths and with water-table elevations. Stormflow water yield is linearly related to soil-moisture content at 70 cm above 37% volumetric moisture content, occurring 20% of the time. Maximum water-table elevation is linearly related to maximum soil-moisture content above a threshold, and the soil-moisture threshold increases with upslope position; the soil-moisture threshold for flow to occur at a trench hillslope site is 41%, occurring $<$0.5% of the time. General relations among streamflow, soil moisture, and water-table response are attributed to variable source areas.
DE: 1829 Groundwater hydrology
DE: 1836 Hydrologic budget (1655)
DE: 1860 Runoff and streamflow
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2003 Fall Meeting