There is a saying â€œfew have died for lack of love; many have died for lack of waterâ€. Water, indeed, is life.
One of Bangladesh principal resources is its water which forms the basis for its transportation system and holds the key to agricultural development. The economic growth and development of Bangladesh has been all highly influenced by water and its regional and seasonal availability and the quality of surface and ground water.
Bangladesh is a riverine country having more than 230 rivers of 11739 km length. For hydrological purposes, the country is divided into six regions â€“ North West, north central, north east, south west, south east and eastern hilly. All the regions are bounded by the major rivers like the Jamuna, the Padma, the Meghna, the old Brahmaputra, etc. all converge empty into the Bay of Bengal. The volume of water is huge. The rivers are estimated to discharge 5.0 million cubic feet water per second at peak period. The contrast between high and low runoff is dramatic. During the lowest month the total runoff is only about 20000 cubic feet per second.
The overall force and movement of water are significant. The sediment carried downstream by the river system has been estimated as 2.4 billion tones annually. Significant amount of lands are eroded by the water movement especially along unprotected river banks. The flooding bring enough slit and makes the soul fertile. The flooding deposits new soils and the ponds of the water left by the flooding can facilitate chemical reactions to produce a nitrogen fixing process in the soils where asequate green algae is present.
Both irrigation and manuring are done by these rivers. Irrigation potential is good. The largest use of water is made for irrigation. Pumping directly from the river provides immediate opportunity due to the ease of access to the water and the low lift requirement to raise water to the land. Additionally, the geological structure produces excellent supplies of underground water which ate readily available for irrigation at less than twenty feet. In general, all areas are suitable for shallow tube well irrigation except for the coastal belt bordering the Bay of Bengal, the Madhupur area, north west of Dhaka, the Barinda area in north Bengal and the entire Sylhet and Chittagong hill tracts region where deep tube wells generally must be used. The supply of ground water has not yet been accurately determined but most estimates indicate that sufficient amounts are available to meet the most projected irrigation demands, although deficiencies could arise during the dry season.
About 69% of the area are irrigated by ground water and rest 31% from surface water. Besides agriculture, some other uses are for domestic and municipal water supply, industry, navigational purpose etc. In addition, water is of fundamental importance for ecology and the wider environment.
Our rivers are also source of energy. Those that have a strong current can produce electricity. The Karnafuli hydroelectric project is an instance of this. We can use the rivers especially the swift flowing ones in the north east region to produce more electricity.
Additionally, the vast water resources provide salt and fresh water habitat for the production and harvest of a wide variety of sea products. Various types of fishes and shrimps are important food sources for both local consumption and for export. About 63% of the total protein need has been satisfied by fishes and contribution to foreign currency income is 5.7%. A significant portion of population of Bangladesh earns a living from fishing and from services associated with water transportation, which is an essential element of the nationâ€™s economy.
The future of the water resources from the river system is in doubt because of a long standing dispute with India over rights. All of the rivers found in Bangladesh initially pass through India and used by Indian farmers. The construction of a barge or a diversion dam on the Ganga (Padma) at Farakka in 1974 to divert greater amount for use in India has created great concern in Bangladesh. The dispute has had adverse consequences for Bangladesh in its attempts to develop flood control and produce electricity involving these waters. Several important projects have been delayed or withdrawn due to the uncertainties of water availability resulting from the diversion dam.
The impacts are-
â€¢ Flow of upstream water is decreasing and ground water level is going down particularly in the dry season and at the same time saline water is introducing to the inland area. Sometimes abundance of water in monsoon causes flood and natural disasters.
â€¢ Water quality in the coastal area is degraded by the intrusion of saline water that has occurred due to lean flow in the dry season.
â€¢ Physical construction changed or damaged the local ecosystem and hydrological features resulting in irreparable damages to fisheries resources.
The increasing urbanization and industrialization of Bangladesh have negative implications for water quality. Pollution level has reached alarming level, marine and aquatic ecosystem is affected and the chemicals that enter the food chain have public health implications. Indiscriminate use of agrochemicals, discharge of pollutants into water bodies is highly responsible for the destruction of aquatic life.
So, responsible authority should take proper step to survive our water resources.