Factors Affecting The Quantity Of Storm Sewage - Civil Engineering

Monday, 19 March 2018

Factors Affecting The Quantity Of Storm Sewage

Factors Affecting The Quantity Of Storm Sewage

The quantity of storm sewage (i.e. stormwater) is mainly affected by the following factors: 

l) Shape And Size of The Catchment Ares

Stormwater(runoff )will be more for large and fan-shaped catchment area. On the other hand, runoff will be less for small and ferm shaped catchment area.

2) Topography

Stormwater increases with the increase in the ground slope of the catchment area and vice versa. 

3) Character of The Catchment Area

If the surface of the catchment area is rocky or compact clayey type, stormwater will be more. Again, if the surface of the catchment area is sandy, the stormwater will be low. 

4) Direction of the prevailing storm

If the direction of the storm is same as the direction of movement of water, the stormwater will be more and vice versa. 

5) Type of Precipitation

If the precipitation occurs in the form of rain, it will produce stormwater immediately. On the other hand, if the precipitation occurs in the form of snow, it will produce stormwater at a slow rate.

6) Rainfall Distribution

The storm water from a basin is very much dependent upon the rainfall distribution. 

7) Intensity and Duration of Rainfall


The stormwater increases with the increase in intensity of rainfall and vice versa. If the duration of rainfall is more, the stormwater will also be prolonged. 

8) Soil moisture Deficiency

The runoff depends upon the soil moisture present at the time of the rainfall. If rain occurs after a long dry period, the soil will absorb huge amounts of water and thus runoff will be less. But the runoff will be more if rain occurs after a long rainy season. 

9) Climatic Condition

If the temperature in the catchment area is high, the evaporation loss will be more and hence the stormwater will be less and vice versa. 

10) Geological Condition of The Catchment

If the catchment area consists of fissures, cracks etc, the water losses will be more and the stormwater will be low.

11) Vegetative Cover


The presence of a dense vegetative cover over soil increases the infiltration and there by reduces the stormwater.
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