Transport of Trace Metals by the Rainwater Runoff in the Urban Catchment of Guwahati, India - Management of Natural Resources in a Changing Environment - page 218

7.5

6.5

5.5

4.5

Runoff Sample

7.5 8.0

7.0 7.5

6.5 7.0

6.0 6.5

5.5

6.0

5.0 5.5

Runoff Sample

Runoff Sample

7.5 7.6

7.0

7.2

6.5

6.8

6.0

6.4

5.5

6.0

Runoff Sample Runoff Sample

7.5

8.0

7.0

7.8

6.5

7.6

6.0

7.4

5.5

5.0

7.2

4.5

7.0

Runoff Sample

Runoff Sample

Fig. 2 Variation of pH in seven runoff locations

that of the natural rainwater that may be attributed to the presence of calcium and
magnesium carbonate/bicarbonate and other alkaline components from soil which
neutralise and compensate the acidity of sulphuric acid and nitric acid (Demirak
et al. 2006 ; Salve et al. 2008 ).