70
3.5 Impact of Rainfall Trend on Trans-boundary
Water Resources
India and Bangladesh are adjacent neighbours, who share 54 rivers and 4096.7 km
terrestrial borders (Rashid 1977). The environment and livelihood of these two
countries are heavily reliant on the trans-boundary river; therefore, any one-sided
and uneven management practice or judgment would being tragic damage to the
whole province (Wirsing et al. 2013). The GBM (the Ganges, the Brahmaputra and
the Meghna) basin constitutes the leading part of the river system in Bangladesh that
serve a total area almost 1.72 million km
2
(Ahmad et al. 2001). This basin receives
more water than it needed for supporting life and economy of their watershed
regions during the peak period (Bandyopadhyay and Perveen 2008) but it dramatically reduced during the lean period. By analysing the rainfall characteristics, it
could be possible to discover if there any significant impact of increasing or decreasing trend on such excess and less flow in the GBM basin. Though, Mirza (2004)
disagreed to consider precipitation changes as the most significant attributed for
decreasing mean discharge in the Ganges. On the other hand, lower riparian countries are mostly suffered from environmental difficulties due to building dams and
barrages for irrigation and other purposes by the upper riparian countries (Kliot
et al. 1997). India has been blamed frequently for creating such obstruction in natural flows of the GBM basins, causing low inflow during dry season can result into
serious environmental degradation (Nishat and Faisal 2000; Faisal 2002). However,
most of the stations in Bangladesh showed increasing trends (60%) in annual rainfall during 1951–2015, among them 33.33% were statistically significant (α = 0.05),
and India was dominated by significant decreasing trend (66.66%). Such increasing
trend of rainfall in Bangladesh during dry season may bring solution to build
respectable relation in these two countries.
3.6 Conclusions
The present study explored the detail spatio-temporal characteristics of precipitation of Bangladesh and India. By analysing the concentration pattern seasonality
and trend of precipitation, it could be assumed that the climate has been changed
adequately within the study period (1951–2015) and the results clearly exhibit a
drastic change of precipitation over whole study area except few pocket area. Such
change in most of the stations makes the region most vulnerable and this practice
continues at medium to high rate, which may cause variation in the sharing of water
between two countries which affects the crop cycles, crop rotation as well as the
total agricultural system. To get more precise evidence, it is rational to link up the
micro-level variations of rainfall with climate change factors and to establish their
relationship with the issue of climate change and agricultural system further studies
are recommended. However, other climatic parameters especially temperature, air
T. Mandal et al.
3.5 Impact of Rainfall Trend on Trans-boundary
Water Resources
India and Bangladesh are adjacent neighbours, who share 54 rivers and 4096.7 km
terrestrial borders (Rashid 1977). The environment and livelihood of these two
countries are heavily reliant on the trans-boundary river; therefore, any one-sided
and uneven management practice or judgment would being tragic damage to the
whole province (Wirsing et al. 2013). The GBM (the Ganges, the Brahmaputra and
the Meghna) basin constitutes the leading part of the river system in Bangladesh that
serve a total area almost 1.72 million km
2
(Ahmad et al. 2001). This basin receives
more water than it needed for supporting life and economy of their watershed
regions during the peak period (Bandyopadhyay and Perveen 2008) but it dramatically reduced during the lean period. By analysing the rainfall characteristics, it
could be possible to discover if there any significant impact of increasing or decreasing trend on such excess and less flow in the GBM basin. Though, Mirza (2004)
disagreed to consider precipitation changes as the most significant attributed for
decreasing mean discharge in the Ganges. On the other hand, lower riparian countries are mostly suffered from environmental difficulties due to building dams and
barrages for irrigation and other purposes by the upper riparian countries (Kliot
et al. 1997). India has been blamed frequently for creating such obstruction in natural flows of the GBM basins, causing low inflow during dry season can result into
serious environmental degradation (Nishat and Faisal 2000; Faisal 2002). However,
most of the stations in Bangladesh showed increasing trends (60%) in annual rainfall during 1951–2015, among them 33.33% were statistically significant (α = 0.05),
and India was dominated by significant decreasing trend (66.66%). Such increasing
trend of rainfall in Bangladesh during dry season may bring solution to build
respectable relation in these two countries.
3.6 Conclusions
The present study explored the detail spatio-temporal characteristics of precipitation of Bangladesh and India. By analysing the concentration pattern seasonality
and trend of precipitation, it could be assumed that the climate has been changed
adequately within the study period (1951–2015) and the results clearly exhibit a
drastic change of precipitation over whole study area except few pocket area. Such
change in most of the stations makes the region most vulnerable and this practice
continues at medium to high rate, which may cause variation in the sharing of water
between two countries which affects the crop cycles, crop rotation as well as the
total agricultural system. To get more precise evidence, it is rational to link up the
micro-level variations of rainfall with climate change factors and to establish their
relationship with the issue of climate change and agricultural system further studies
are recommended. However, other climatic parameters especially temperature, air
T. Mandal et al.