Assessment of Seasonal and Annual Rainfall Trends and Variability in Sharjah City, UAE
Table 5
Comparing long-term mean monthly trends using standard MK test and seasonal MK test for the periods from 1934 to 2014, from 1934 to 1977, and from 1977 to 2014.
Month
Season
Entire data set
Old airport data set
New airport data set
1934–2014
1934–1976
1977–2014
LRS
MK with AC
Seasonal MK
LRS
MK with AC
Seasonal MK
LRS
MK with AC
Seasonal MK
val.
SS
val.
SS
val.
SS
val.
SS
val.
SS
val.
SS
Jan.
Winter
−0.11
0.523
−0.018
0.342
+0.26
+0.50
0.677
0.000
0.543
+1.50
+0.22
0.384
+0.005
0.658
+0.80
Feb.
Winter
−0.02
0.828
0.00
0.914
−0.06
−0.07
0.035
−0.001
0.465
−0.75
−0.98
0.043
−0.279
0.566
−6.35
Mar.
Winter
+0.29
0.238
+0.01
0.143
+0.96
+0.04
<0.001
−0.036
0.694
−0.25
−0.67
<0.001
−0.303
0.239
−5.11
Apr.
Spring
+0.02
<0.001
+0.001
0.135
+0.003
+0.10
0.00
0.00
—
0.00
+0.01
0.169
0.546
−0.52
May
Spring
−0.03
0.390
0.00
—
0.00
+0.14
0.487
0.00
—
0.00
−0.06
0.743
0.00
—
0.00
Jun.
Summer
+0.02
0.677
0.00
—
0.00
+0.00
0.226
0.00
—
0.00
+0.02
0.218
0.00
—
0.00
Jul.
Summer
+0.04
0.108
0.00
—
0.00
+0.014
0.050
0.00
—
0.00
+0.060
0.046
0.00
—
0.00
Aug.
Summer
0.00
0.073
0.00
—
0.00
+0.005
0.087
0.00
—
0.00
+0.002
0.541
0.00
—
0.00
Sep.
Summer
+0.05
0.378
0.00
—
0.00
+0.00
0.050
0.00
—
0.00
+0.15
0.024
0.00
—
0.00
Oct.
Autumn
+0.02
0.024
0.00
—
0.00
+0.02
0.158
0.00
—
0.00
+0.02
0.120
0.00
—
0.00
Nov.
Autumn
−0.13
0.332
0.00
1.000
0.00
−0.32
0.095
0.00
—
0.00
+0.06
0.001
0.00
—
0.00
Dec.
Winter
+0.09
0.013
−0.011
0.336
−0.37
−0.75
<0.001
−0.280
0.239
−0.63
+0.23
0.357
1.00
−0.10
LRS: linear regression slope; SS: Sen’s slope; MK with AC: Mann-Kendell test with autocorellation by the method of Yue and Wong; val.: value of MK test by Monte Carlo Simulation; positive and negative signs of slopes indicate decreasing trend and increasing trend, respectively. “—”: test cannot be computed as some sequences are constant. All MK tests were performed using one-tailed test with 5% significance level.
