30
20
10
0
20
40
60
80
100
120
Time (h)
Figure 6. Discharge from a forested watershed. The discharge begins to
increase more quickly at 51 hours, peaks at 85 hours at 16.34 m3/s, then
decreases until the end of the simulation. Please note that the discharge from
the forested watershed differs from the discharge from agricultural and sub-
urban watersheds shown in Figures 7 and 8.
impervious area and the most amount of pervious area because forested watersheds are least de-
veloped of all watersheds.
Figure 6 shows the discharge from the forested watershed. The discharge begins to increase more
quickly at 51 hours, reaches a maximum of 16.34 m3/s at 85 hours, and then descends to the end of
the simulation.
Agricultural watershed simulation
The agricultural watershed was assigned less depression storage than the forested watershed be-
cause the surfaces of agricultural watersheds are mechanically smoothed to grow crops. Furthermore
the agricultural watershed was assigned more depression storage than the suburban watershed be-
cause rows of depression storage are created by the plowing of agricultural fields. Like the forested
watershed, the impervious part of the agricultural watershed was assigned a value of zero for depres-
sion storage. The agricultural watershed was assigned a smaller value of hydraulic conductivity than
the forested watershed, because agricultural watersheds lack the extensive root systems present in
forested watersheds. Finally, the agricultural watershed was assigned more impervious area than the
forested watershed, because agricultural watersheds are more developed than the forested water-
sheds.
Figure 7 shows the discharge from the agricultural watershed. The discharge begins to increase
more quickly at 50 hours, reaches a maximum of 23.41 m3/s at 84 hours, and decreases until the end
of the simulation. Please note that the peak of this hydrograph is larger and occurs one hour earlier
than the peak of the hydrograph in Figure 6. The hydrographs in Figures 6 and 7 differ because the
agricultural watershed infiltrates less water than the forested watershed, and it consequently produc-
es more runoff and less subsurface and base flow than the forested watershed (larger amounts of
runoff and smaller amounts of subsurface and base flow result in larger values of peak discharge and
shorter times to peak discharge).
Suburban watershed simulation
The suburban watershed was assigned the least amount of depression storage of all the water-
sheds, because most surfaces in suburban watersheds are either paved or mechanically smoothed.
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