Characteristics of Temperature and Rainfall in Bangladesh: A historical Perspective 1948-2011

Abstract

Climate change is regarded as the
greatest long-term threat to the
development of Bangladesh. The article
provides an assessment of climate change
and variability based on analysis of
historical data of temperature and rainfall
recorded at 34 meteorological stations
located at seven regions in Bangladesh for
the period of 1948-2011. Analysis of
temperature data showed an increasing
trend in the yearly average temperature at
majority of these stations. During this
period, the yearly average temperature in
the country increased by 0.52°C at a rate
of 0.01°C per year. The magnitude of
increase in monthly average temperature
from 1976 to 20011 of the total study
period was sharply higher than the
average. Moreover, significant increase of
maximum temperature was observed in
Khulna and Barishal, whereas, minimum
temperature was recorded in Sylhet and
Rangpur. The rainfall difference from 1953
to 2011 was -107.71 mm. Post-monsoon
rainfall showed an increasing trend during
the period of 1953-2011 in majority of
regions. In contrast, there was a
decreasing trend in total rainfall during
monsoon. There was no significant change
in pre-monsoon total rainfall. In general,
these trends are consistent with the
general climate change predictions. The
maximum rainfall significantly increased in
Sylhet and Chittagong while minimum
rainfall was recorded in Khulna and
Rajshahi regions. The temperature and
rainfall patterns are of great importance
for an agro-based economy like
Bangladesh. Moreover, these changes will
threaten the significant achievements.
There was an inverse and positive
relationship between the average
temperature and values of SOI and IOD.
These observations are particularly
significant in the context of Bangladesh
where agriculture is heavily dependent on
temperature and rainfall patterns.