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Wallace test, Bartlett test, Tukey test, von Neumann test, Cumulative Deviation
test and Bayesian test. Theoretical backgrounds of these statistical tests are
provided in Chapter 4 (Section 4.1). The trend and homogeneity tests were
applied separately for pre- and post-monsoon seasons using 16 years (1991-
2006) groundwater level time series data of 140 sites. Thus, in total, ten time
series tests were applied to 280 individual groundwater level time series.
Finally, trend and homogeneity were examined in the annual net recharge
time series of 16 years (1991-2006) at 140 sites over the study area by applying
three trend tests and seven homogeneity tests. To accomplish these tasks,
spreadsheet programs were developed using MS-Excel software.
8.4 Spatial and Temporal Variations of Annual Rainfall
8.4.1 Annual Rainfall Pattern
The long-term variation of rainfall is also of prime importance for the efficient
management of water resources. The variation of annual rainfalls over the
study area along with the 43-year mean annual rainfall is shown with the help
of box and whisker plots in Fig. 8.2. It is evident from this figure that the
temporal variation of annual rainfall is the highest for Kotra rainfall station
and the median rainfalls of Dhariawad and Kotra stations are more than the
43-year mean annual rainfall (662 mm) in the area. It is also revealed from the
box and whisker plots (Fig. 8.2) that some outliers and/or extreme rainfall
events occurred during the 43-year period at almost all the ten rainfall stations
in the study area. The outliers and extremes were detected by the STATISTICA
software, which considers a data point to be an outlier if the data point is
Fig. 8.2.
Spatial variation of 43-year period annual rainfalls.
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