CONCLUSION
The following conclusions are come from the above research;
Geospatial interpolation is used in order to represent the spatial
variation of rainfall in the Assam region.
- Comparison of five geospatial interpolation techniques (amounting to a
total of 20) applied for monthly average precipitation data for state
of Assam; India for a period of 30 years ranging from 1988 to 2018
proved that choice of interpolation technique highly affects the
results.
- From the comparison it was found that IDW for weight parameter p = 3
gave the best performance as compared to all other methods. There are
few other methods which performed well they were universal Kriging and
RBF.
- The cross validation of the results shows that the predicted values
are close to the observed values and these results can be efficiently
used for research works that requires precipitation data for any place
which is un-gauged.
- This work will also act as guidance to opt for the best technique
among various geospatial interpolations available for interpolation.
- Using the best interpolation method obtained (IDW at p=3) temporal
variation of the precipitation is determined.
- Figure 10-11 shows spatial and temporal variation of rainfall. It is
found that precipitation is intense in Lakhimpur district of upper
Assam and Kokrajhar district of lower Assam which reaches to 820mm -
850mm during monsoon season.
- Figures 10 illustrate that during Monsoon, middle Assam (Nagaon, Karbi
Anglong, Sonitpur) experienced less precipitation as compared to other
regions. Middle Assam which is 250mm – 350mm
- Temporal variation of rainfall shows that minimum rainfall is observed
during December (Figure 11. b) which amounts to a maximum of 15mm –
17mm in Cachar region and 1mm - 4mm in lower Assam region.