Geoscience Reference
In-Depth Information
Fig. 7.
Location of the Godavari delta.
soils with sandy subsoils representing the coastal sand are also found along
the sea.
The delta has a network of canal systems and increased use of new crops
along with chemical fertilizers and pesticides have brought about rapid
growth in the agricultural output. The crops irrigated with river water
throughout the year except between the last week of April and the second
week of June. As ample surface water is made available to irrigate the
delta, there has been no effort to use groundwater. Potassium fertilizers are
extensively used for increasing the crop yield. The variation in potassium
concentrations in groundwater in the study area is shown in Fig. 8. The
peak values are generally observed in November. Higher concentrations are
found due to the application of potash fertilizer besides contribution from
soils. The temporal variation of chloride and bicarbonate from groundwater
samplesisshowninFig.9.
The ratio of chloride/bicarbonate + carbonate can be used as criteria to
evaluate seawater intrusion. Chloride is the dominant ion in seawater and
