Environmental Engineering Reference
In-Depth Information
Hemisphere
Truncated
cone
Circular cone
Water-surface elevation
FIGURE 11.4
Examples of the shapes of hypsographic curves, surface areas versus depth or elevation, for
representative geometric shapes.
11.3.5 V
oLuMe
-d
eptH
c
urVeS
The volume of a lake or a reservoir is also a basic distinguishing characteristic that affects the
quantities of materials in the lake, the impacts of sedimentation, the residence time, and the water
available for given management purposes.
Similar to area, volume is a function of depth and the relationship is expressed as a depth-
volume curve, similar to a hypsographic curve. The shape of the curve can provide information
about the general shape of the lake or reservoir, as illustrated in Figure 11.5.
The management of reservoirs is usually based on their storage capacity and inlows in order to
manage outlows, based on the relationship:
∆
∆
S
t
=−
IO
(11.1)
where
S
indicates storage (volume)
t
is time
I
is the sum of the inlows
O
is the sum of the outlows
Truncated cone
Hemisphere
Circular cone
Water-surface elevation
FIGURE 11.5
Comparison of depth-volume curves for three geometric shapes.
Search WWH ::
Custom Search