Water Conservation and Management for Healthy Life of Rivers in the Atrai and Baral Basins of Bangladesh

摘要

The river system that flows through Bangladesh comprises the third largest source of fresh - water discharge in the world. Total flows of the three major rivers, Ganges, Brahmaputra and Meghna only follow that of the Amazon in Brazil and the Congo in Africa. It is note worthy to mention here that 237 rivers are flowing through Bangladesh of which 57 from across the border. The annual volume of flows passed below the confluence of the Ganges and the Brahmaputra is about 795,000 cubic meters, which is equivalent to about 5.5 meters of depth over the country. On an average, the country receives annual rainfall of about 200 cm, almost 90% of it is during the monsoon. Therefore, with available annual water, a water body of about 7.5 meters depth will be over the country if accumulated and not flowing to the Bay of Bengal. But the country faces water shortage during November to May and is subject to flood every year due to uneven distribution of river flows and rainfall. Most of the Northwest and Southwest regions become dry especially during March to May. Rivers in these areas become dead during this part of the year and become alive with onset of monsoon. Rivers in the central area and eastern part of Bangladesh have better access to water due to tidal flows from the Bay of Bengal at least during high tides. In this paper, approaches have been suggested to keep rivers in Atrai and Baral basins (Fig. 1) alive for the whole year through improved management. This will further assist in incremental crop and fish production. Healthy rivers in Atrai and Baral basins will contribute to creation of water body through water conservation and management especially from the end of monsoon and will provide opportunities for groundwater recharge in the area. This may further contribute to expansion of irrigated area and minimizing level of arsenic contamination of groundwater. There will be better environment through increased vegetation and available water body during dry months (November to May). During June to October, all rivers in Bangladesh including those in the Atria and Baral basins have very healthy life and often cause flood. Flood problem is not covered in this paper as it involves bigger dimension of the problem, which is also required for overall improved agricultural production environment, safety of people and infrastructures. Development options for maintaining healthy life of the rivers and improved production environment through integrated land and water resources are explained in this paper for the Atrai and Baral river basins, which is part of the Northwest region of Bangladesh.