Hello, this peak discharge data were collected from two watersheds (one logged, one un-logged) at the HJ Andrews Experimental Forest in Blue River, Oregon. Link is here. Both watersheds have similar elevation and lie on the western slopes of the Oregon Cascades in the Willamette National Forest.
The logged (i.e. treated) watershed in the study was 100% clear-cut -- presumably at the beginning of the research. It is not clear whether additional clear cutting was performed during the period of study. The un-logged watershed (i.e. the "control") had vegetation consisting mainly of "100- to 500-year-old Douglas fir, western hemlock, and western red cedar in closed canopy stands, with increasing amounts of Pacific silver fir above 800 m."
Peak discharge from both watersheds was collected for 352 storm events. To eliminate the effects of area on discharge, the data must be adjusted or "normalized". This is done by dividing discharge by basin area to give what is referred to as "Unit Discharge", with measurement units in "cubic meters per second per square kilometer" (m3/s/km2). Unit discharge tells us how much flow comes off a standard sized piece of land in the watershed, on average.
This data set is in agreement with these facts: we observe that for most storm events, peak unit discharge is always higher in the logged watershed. On the graph, we observe that most data points lie above the imaginary 45 degree or y = x line, indicating that the x coordinate (un-logged) is smaller that the y coordinate (logged).
The logged (i.e. treated) watershed in the study was 100% clear-cut -- presumably at the beginning of the research. It is not clear whether additional clear cutting was performed during the period of study. The un-logged watershed (i.e. the "control") had vegetation consisting mainly of "100- to 500-year-old Douglas fir, western hemlock, and western red cedar in closed canopy stands, with increasing amounts of Pacific silver fir above 800 m."
Peak discharge from both watersheds was collected for 352 storm events. To eliminate the effects of area on discharge, the data must be adjusted or "normalized". This is done by dividing discharge by basin area to give what is referred to as "Unit Discharge", with measurement units in "cubic meters per second per square kilometer" (m3/s/km2). Unit discharge tells us how much flow comes off a standard sized piece of land in the watershed, on average.
This data set is in agreement with these facts: we observe that for most storm events, peak unit discharge is always higher in the logged watershed. On the graph, we observe that most data points lie above the imaginary 45 degree or y = x line, indicating that the x coordinate (un-logged) is smaller that the y coordinate (logged).
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