1* CHAPTER III
3.5 Correlation coefficients between WBT of March-May and Rainfall of March- May
3.5 Correlation coefficients between WBT of March-May and Rainfall of March-
positive and negative values of CC are observed at Rangpur and Madaripur are 0.46 and -
0.66, respectively, which are significant at 99% level
The distribution of CC between the WBT of April and the rainfall of May is shown in Fig 3.5.2(c). The figure shows that from the central part CC is positive at everywhere towards north, north-west and north-eastern part of the country except Ishwardi. Most of the southern and south-western part of the country has also a positive CC. Comilla-Feni- Sitakundu belt has a negative CC. The maximum positive and negative values of CC are observed at Sylhet and Corn illa are 0.24 and -0.27, respectively.
3.5.3 Distribution of the CC between WBT of May and rainfall of March, April and May
The distribution of CC between the WBT of May and the rainfall of March is shown in Fig 3.5.3(a). From the distribution pattern we see that the CC is positive at the northern, north-western and north-eastern part of Bangladesh. The CC is mostly negative at the central part and mostly positive at the southern part of the country. The maximum positive and negative values of CC are observed at Patuakhali and Teknaf are 0.31 and -
0.30, respectively.
The distribution of CC between the WBT of May and the rainfall of April is shown in Fig 3.5.3(b). The figure shows that the distribution of CC is negative all over the country except Dinajpur, Rangpur, Mymensing, Ishwardi, Jessore, Maizdy Court and Sitakundu region. The maximum positive and negative CC is observed at Sitakundu and Khulna and is 0.21 and -0.49 respectively.
The distribution of CC between the WBT of May and the rainfall of May is shown in Fig 3.5.3(c). This figure shows that the distribution of CC at all over the country is negative except Faridpur, Jessore, Chandpur and Satkhira. The maximum positive and negative CC is observed at Chandpur and Sitakundu and is 0.12 and -0.56, respectively.
67
3.5.4 Distribution of CC between Pre-monsoon WBT and rainfall of March, April and May
The distribution of CC between the average pre-monsoon WBT and the rainfall of March is shown in Fig 3.5.4(a). The figure shows that the distribution of CC is positive at Ishwardi-Bogra-Mymensing-Sylhet belt. It is negative at almost all the places in the southern, south-eastern and eastern part of the country. The maximum positive and negative CC is observed at Patuakhali and Sitakundu and is 0.38 and -0.38, respectively.
The CC is significant about 95% level at Patuakhali and Sitakundu.
The distribution of CC between the average pre-monsoon WBT and the rainfall of April is shown in Fig 3.5.4(b). From the distribution pattern we see that starting from the middle part of the country the CC is positive everywhere towards the north and north- western part of Bangladesh. It is also negative at most of the places towards south, south- east and south-western part of the country. The maximum positive and negative CC is observed at Rangpur and Comilla and is 0.37 and -0.44, respectively. The CC is significant about 99% level at Comilla and Rangpur.
The distribution of CC between the average pre-monsoon WBT and the rainfall of May is shown in Fig 3.5.4(c). The figure shows that the distribution of CC is positive at all of the northern and north-western part of the country except Dinajpur and Rangpur. It is also positive at some places of the south-western and middle part of Bangladesh. The eastern and southern part has a negative CC. The maximum positive and negative CC is observed at Satkhira and Sitakundu and is 0.46 and -0.50, respectively. At Satkhira and Sitakundu the CC is significant of about 99% level.
3.5.5 Distribution of the CC between average Pre-monsoon rainfall and WBT of March, April and May and the Pre-monsoon season itself
The distribution of CC between the WBT of March and the average pre-monsoon rainfall is shown in Fig 3.5.5(a). From the distribution pattern we see that the CC is positive at everywhere towards the north, north-east and north-west from the middle part of Bangladesh. It is also positive at many of the remaining part of the country towards south, south-west and south-east from the central part. The negative CC is observed at Patuakhali and Sitakundu region. The maximum positive and negative CC is observed at
Satkhira and Sitakundu and is 0.34 and -0.30, respectively. The CC is significant about 99% level at Satkhira.
The distribution of CC between the WBT of April and the average pre-monsoon rainfall is shown in Fig 3.5.5(b). From the distribution pattern we see that the CC distribution is positive at all the places from the central to the northern and north-western part of the country. At eastern and southern part of the country the CC is mostly negative.
The maximum positive and negative CC is observed at Satkhira and Madaripur and is 0.37 and -0.52, respectively. At both of the places the CC is significant at 99% level.
The distribution of CC between the WBT of May and the pre-monsoon rainfall is shown in Fig 3.5.5(c). The CC distribution is negative all over the country except Ishwardi. This distribution pattern has no similarity with that of the CC distribution pattern of WBT of March and April and the pre-monsoon rainfall. The only positive CC is observed at Ishwardi which is 0.06. The maximum negative CC is observed at Khulna - 0.50 which is significant at 99% level.
The distribution of CC between the average Pre-monsoon WBT and average pre- monsoon rainfall is shown in Fig 3.5.5(d). The CC distribution is positive at all over the northern part of the country except the extreme north. All over the south-eastern and southern part has a negative CC. The maximum positive and negative CC is observed at Satkhira and Feni and is 0.39 and -0.58, respectively. The CC is significant about 99%
level at Satkhira and Feni.
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