Thus, even during large snow years, groundwater levels in Crane Flat would not sustain peat forming conditions as occur at Drosera and Mono Meadows. The meadow water table responded rapidly to precipitation events. A 3.0 cm precipitation event on June 30, 2004
produced a 10–20 cm water table rise that lasted for more than 6 days. A 10.8 cm precipitation event on October 16, 2004 led to a 100 cm water level rise at all wells. For all years, 2004–2010, when the hydraulic head in piezometer 49 was within the peat body (above 130 cm bgs), the water level at the start of a 6-h pumping period explained 72% of the variation in how far the water level was drawn down (P ≪ 0.0001, R2adj = 0.7172, 537 df). A greater 6-h drawdown occurred when the initial http://www.selleckchem.com/products/epacadostat-incb024360.html water levels were lower (black-outlined triangles, Fig. 4). However, when the head in piezometer 49 dropped below the peat body the relationship reversed and lower initial water levels resulted in less total 6-hr drawdown (P ≪ 0.0001, R2adj = 0.2728,
111 df; gray-outlined triangles in Fig. 4). Pre-pumping water levels were always within the peat body, but when the initial water level was 70 cm bgs or lower, the 6-h pumping always resulted in heads below the peat body. The water level drawdown in well 10 was negatively correlated with the initial groundwater level (black-outlined circles, Fig. 4). Deeper initial water levels resulted in smaller drawdowns, Protein kinase N1 although this correlation only accounted for 3% of the variation in drawdown (P = 0.0002, Endocrinology antagonist R2adj = 0.0314, 411 df). Calibrated hydraulic conductivities ranged from 10 m/d in the top layer to 0.3 m/d in the bottom layer. These values bracket the hydraulic conductivity (4.4 m/d) that was estimated during an October 2005 aquifer test and are within typical ranges reported for
sands and weathered granite (Freeze and Cherry, 1979). The low-conductivity value used in the west arm area was 0.04 m/d. Excluding the peat, the calibrated specific yield was 0.25 in the top layer and 0.1 in all other layers. Transient modeling results were not sensitive to specific storage values. Using observed hydraulic heads from early June 2004, the mean error and mean absolute error (MAE) for the steady-state model are 0.02 m and 0.12 m, respectively. The observed heads ranged from 1873.05 m to 1875.71 m. The model reasonably reproduces the heads over the entire data range; the MAE/range is 0.045. Simulated inflow in the steady-state model included spring flow at the southwest boundary (22.6 m3/d), flow across the northern head-dependent boundary (27.9 m3/d), and areal recharge derived from precipitation (25.6 m3/d). The simulated outflow across the southeast boundary was 76.1 m3/d. The transient model provided a good match to observed hydraulic heads in the central and southern parts of the meadow (Fig. 5).