Watershed 18

Physical Characteristics
STREAM: Grady Branch
AREA: 13 ha
FIRST RECORD: 07/03/1936
NOTCH: 120 V-notch
ELEV. at WEIR: 726 m
MAX ELEVATION: 993 m
MAX DISCHARGE: 1.36 m3sec-1km-2
ASPECT: Northwest

Parameters from Swank and Crossly (1988)
Average Annual Nutrient (kg ha-1) and Water (cm) Budget:

 

Input

Output

Net Difference

Water

206

119

+87

NO3-N

2.97

0.04

+2.93

NH4-N

1.97

0.03

+1.94

PO4-P

0.09

0.02

+0.07

SO4-S

10.72

1.64

+9.08

Cl

5.72

6.3

-0.58

K

1.98

4.93

-2.95

Na

3.56

10.31

-6.75

Ca

4

7.03

-3.03

Mg

0.85

3.49

-2.64

SiO2

0.62

83.69

-83.07

Volume-Weighted Mean Annual Concentrations 1973-83:
NO-3-N = 0
NH+4-N = 0
PO3-4-N = 0
Cl- = 0.53
K+ = 0.41
Na+ = 0.86
Ca2+ = 0.59
Mg2+ = 0.29
SO2-4-S = 0.14
SiO2 = 7.01

Some Physiographic and Mean Hydrologic Characteristics:
Land Slope (%) = 52
Record Length (yr) = 45
Mean Annual Precipitation (cm) = 193.9
Mean Annual Runoff (cm) = 103.42
Precipitation Runoff (cm) = 90.48
Hursh's Runoff Coefficient = Mean Annual Runoff/Mean Annual Precipitation = 0.54
Initial Flow Rate (l/s/km2) = 29.54
Quickflow Before Peak (cm) = 2.73
Quickflow After Peak (cm) = 7
Delayed Flow (cm) = 93.69
Storm Duration (hr) = 13.5
Time To Peak (hr) = 4.11
Absolute Peak (l/s/km2) = 79.97
Recession Time (hr) = 9.39
Mean Runoff Events/Year = 79
Response Factor: (Qflow Before Pk + Qflow After Pk) / Mean Annual Precipitation = 0.05
Hursh's Storm Runoff Ratio: (Qflow Before Pk + Qflow After Pk)/Mean Annual Runoff = 0.09

Summary of Treatments
Controls with mixed hardwoods stands remaining undisturbed since 1927.

Aquatic Research
Discharge for WS18 and WS27 measured with 120 degree sharp-crested V-notch weirs:
- Watershed 18 daily stream discharge.
- Watershed 27 daily stream discharge.

Terrestrial Research
Microclimate (Gradient).
Nitrogen Transformation (Gradient).
Litterfall (Gradient) Group 1.
Litterfall (Gradient) Group 2.
Litterfall (Gradient) Group 3.
Litterfall (Gradient) Group 4.
Litterfall (Gradient) Group 5.
Litterfall (Gradient) Group 6.
Litterfall (Gradient) Group 7.
Dendrometer Bands (Gradient).
Soil Moisture (TDR Gradient).
Annual rates of fine root appearance and disappearance (Gradient).
Seasonal dynamics of fine root length (Gradient).
Fine root length (Raw Data Gradient).
Root Mass (Raw Data Gradient).
Canopy Gradient Thrufall.
Canopy Gradient Frass.
Soil Chemistry along the canopy gradient.
Tree population dynamics along environmental gradients.
Microclimate (Gap).
Dendrometer Bands (Gap).
Soil Moisture (TDR Gap).
Photosynthetic Active Radiation (PAR Gap).