Environmental Engineering Reference
In-Depth Information
The fluxes calculated at each sample point location, reflect the background flux plus
the flux generated by the storm water of the corresponding drainage area and the
upstream areas during the period of study. The location C
|
reflects the pollution load
mainly from storm water, contributed to the stream by drainage area C. The final flux,
downstream to Marimba River, includes the contribution from drainage area A, shown
down stream of point A
|
(the discharge point of the stream collecting runoff from area
A).The same procedure should be applied to the rest of the parameters measured for a full
evaluation of the pollution fluxes and their variation.
4.3.2
Results
The results (Fig. 5.7) show that the major pollution flux is generated between the control
point and point F. This drainage area is with a low percentage of impervious cover and
correspondingly does not contribute
Figure 5.7. Variation of pollution
fluxes along the stream with respect to
ammonia.
a significant volume of runoff. For the whole study period, the runoff from area F formed
only 0.5% of the base flow volume. Therefore, the sharp increase in the pollution flux is
due mainly to the increased ammonia con-centration between the two points, which could
be explained only with pollution generated by the solid wastes dumped in and around the
stream bed.
This trend was sustained for the rest of the parameters as well. It shows the importance
of maintaining natural water bodies clean of litter and solid wastes. The cleaning of the
streambed could reduce 80-90% of the diffuse pollution load contributed to Marimba
River from this tributary, especially during dry season conditions.
