But we dont do anything against the Killer India.
From: Isha Khan <bdmailer@gmail.com>
To: dhakamails@yahoogroups.com
Sent: Fri, January 22, 2010 6:53:18 AM
Subject: [Dahuk]: The dying Ganges
The dying Ganges
THE Ganges, one of the largest rivers in the world, is providing fresh water to 500 million people in South Asia. The river is particularly important in delivering waters for domestic, industrial, and agricultural sustainability in the region. About 37% (area-wise) of Bangladesh depends solely on the Ganges for freshwater supply, which is not only supporting millions of lives but is also substantially important in maintaining the ecological balance of south-west Bangladesh as well as the largest mangrove forest, the Sundarbans.
In 1975, India commissioned a barrage on the Ganges at Farakka, 18 km above the India-Bangladesh border, in order to divert a portion of dry season flow to increase the navigability of Calcutta port. Right after it went into operation in 1975, the freshwater supply of the Ganges decreased considerably, with a number of consequent effects in the south-west part of Bangladesh.
For instance, the Ganges-Kobadak project, popularly known as the G-K project, is facing acute water shortage since commissioning of the barrage. Salinity both in surface water and in groundwater increased significantly, which is affecting agricultural production and drinking water availability. In effect, public heath in the Ganges dependent area is under severe threat.
Around 685 km of waterways have already disappeared, and erosion and deposition patterns have changed noticeably. The top-dying disease of Sundari trees in the Sundarbans is believed to be the result of reduced flows of the Ganges. This situation will be aggravated in the context of climate change as IPCC, in 2007, warned that the headwater source of the Ganges at the Gangotri glacier was going to disappear by 2035.
Another study reported that rainfall would be 3-7 times higher in the coming decades due to climate change, which may result in more frequent and catastrophic flooding in Bangladesh. The depositing of sediment of the Ganges system would change dramatically, which could have spectacular impacts on erosion and deposition patterns.
This write-up can be of use in discerning the morphological situation of the Ganges in Bangladesh. Long-term remotely sensed data (1972-2008), mean monthly discharge at Hardinge Bridge (1934-2008) and rainfall data of 10 stations of south-west area (1950-2008) of Bangladesh were utilised. Geographic Information Systems (GIS) was used to estimate morphological changes between 1972 and 2008.
Planform analysis revealed that both the right and the left banks of the river underwent dramatic changes since 1972, and the changes were particularly evident during the period before the treaty between the two countries. The main course of the Ganges widened many times in many places in 1984, 1989 and 1995, indicating severe lateral erosion. Erosion was more pronounced near the Ganges-Jamuna confluence near Aricha. Erosion rate per year was about 85 sq. km from 1972 to 1984. The highest erosion was observed in 1984, when more than 160 sqkm land was eroded. During 2001-2008, erosion rate reduced to about 65 sqkm/year.
In contrast, deposition of the Ganges has been increasing with the span of time, which may be attributed to soil erosion upstream as well as increasing human interventions on natural flows.. Estimation showed that in 1972, char areas in the Ganges measured 312 sqkm, whereas in 1984 and 2008, char areas increased significantly. Total areas of chars were 454 and 360 sqkm in 1984 and 2008, respectively. Calculation of sinuosity index showed that the Ganges is turning to wandering shape, meaning that the river is neither braided nor meandering in shape. In addition, few pockets throughout its course are being developed, where many-fold increase of lateral erosion is observed.
An assessment has been made to correlate these morphological changes with water flows and rainfall. The water flow data was divided into treaty and non-treaty periods. This computation clearly indicates that the morpohology of the Ganges is highly correlated with the consistent flows from upstream.
Though a 30-year water treaty has been in effect between the two countries since 1996, recent water flow analysis revealed that Bangladesh is being deprived of its due share during lean season. However, wet season flows of the Ganges have been on the rise in recent years.
Consequently, many tributaries and distributaries of the Ganges are being filled up as a result of increasing sedimentation. The Gorai, which plays a crucial role in flushing salinity further downstream, virtually dries up during dry season. Hence, to keep the Gorai river flowing, the Bangladesh government has started dredging that costs a good amount of money. Rainfall analysis of 10 stations in the Ganges dependent area of Bangladesh shows very subtle changes in the rainfall regime. Hence, water diversion by India is the only factor for the recent morphological changes in the Ganges basin in Bangladesh.
It is claimed that the normal flow of the Ganges from its source has been less than in the past and withdrawal of waters using 34 dams including Farakka in the upstream does have a significant impact on Bangladesh and its economy. If this situation continues, 37% (area wise) and one-third of the population of Bangladesh will face a critical situation in the coming decades. Probable climatic change may also aggravate the hydrological effects.
In order to keep the Ganges system alive, Bangladesh should have undertaken the construction of the proposed Ganges Barrage, which would help us to save water to be used during dry season. In addition, the Joint River Commission should play an active role to monitor the guaranteed water flow stipulated in the 1996 treaty.
Management of the large amount of sediment deposited by this river should also be taken into account in order to save people and agricultural lands from persistent water-logging, which has become a common phenomenon in Jessore and Sathkira region due to siltation in the river beds.
Since India agreed to consider Bangladesh's claim on water resources during the recent visit of Bangladesh's prime minister in New Delhi, we should keep demanding our due share according to the 1996 treaty. If we fail to maintain continuous flows in the Ganges system, it will be really impossible for us to save the environment and ecosystem of the entire south-west region of Bangladesh, including the largest mangrove forest of the world, the Sundarbans.
In 1975, India commissioned a barrage on the Ganges at Farakka, 18 km above the India-Bangladesh border, in order to divert a portion of dry season flow to increase the navigability of Calcutta port. Right after it went into operation in 1975, the freshwater supply of the Ganges decreased considerably, with a number of consequent effects in the south-west part of Bangladesh.
For instance, the Ganges-Kobadak project, popularly known as the G-K project, is facing acute water shortage since commissioning of the barrage. Salinity both in surface water and in groundwater increased significantly, which is affecting agricultural production and drinking water availability. In effect, public heath in the Ganges dependent area is under severe threat.
Around 685 km of waterways have already disappeared, and erosion and deposition patterns have changed noticeably. The top-dying disease of Sundari trees in the Sundarbans is believed to be the result of reduced flows of the Ganges. This situation will be aggravated in the context of climate change as IPCC, in 2007, warned that the headwater source of the Ganges at the Gangotri glacier was going to disappear by 2035.
Another study reported that rainfall would be 3-7 times higher in the coming decades due to climate change, which may result in more frequent and catastrophic flooding in Bangladesh. The depositing of sediment of the Ganges system would change dramatically, which could have spectacular impacts on erosion and deposition patterns.
This write-up can be of use in discerning the morphological situation of the Ganges in Bangladesh. Long-term remotely sensed data (1972-2008), mean monthly discharge at Hardinge Bridge (1934-2008) and rainfall data of 10 stations of south-west area (1950-2008) of Bangladesh were utilised. Geographic Information Systems (GIS) was used to estimate morphological changes between 1972 and 2008.
Planform analysis revealed that both the right and the left banks of the river underwent dramatic changes since 1972, and the changes were particularly evident during the period before the treaty between the two countries. The main course of the Ganges widened many times in many places in 1984, 1989 and 1995, indicating severe lateral erosion. Erosion was more pronounced near the Ganges-Jamuna confluence near Aricha. Erosion rate per year was about 85 sq. km from 1972 to 1984. The highest erosion was observed in 1984, when more than 160 sqkm land was eroded. During 2001-2008, erosion rate reduced to about 65 sqkm/year.
In contrast, deposition of the Ganges has been increasing with the span of time, which may be attributed to soil erosion upstream as well as increasing human interventions on natural flows.. Estimation showed that in 1972, char areas in the Ganges measured 312 sqkm, whereas in 1984 and 2008, char areas increased significantly. Total areas of chars were 454 and 360 sqkm in 1984 and 2008, respectively. Calculation of sinuosity index showed that the Ganges is turning to wandering shape, meaning that the river is neither braided nor meandering in shape. In addition, few pockets throughout its course are being developed, where many-fold increase of lateral erosion is observed.
An assessment has been made to correlate these morphological changes with water flows and rainfall. The water flow data was divided into treaty and non-treaty periods. This computation clearly indicates that the morpohology of the Ganges is highly correlated with the consistent flows from upstream.
Though a 30-year water treaty has been in effect between the two countries since 1996, recent water flow analysis revealed that Bangladesh is being deprived of its due share during lean season. However, wet season flows of the Ganges have been on the rise in recent years.
Consequently, many tributaries and distributaries of the Ganges are being filled up as a result of increasing sedimentation. The Gorai, which plays a crucial role in flushing salinity further downstream, virtually dries up during dry season. Hence, to keep the Gorai river flowing, the Bangladesh government has started dredging that costs a good amount of money. Rainfall analysis of 10 stations in the Ganges dependent area of Bangladesh shows very subtle changes in the rainfall regime. Hence, water diversion by India is the only factor for the recent morphological changes in the Ganges basin in Bangladesh.
It is claimed that the normal flow of the Ganges from its source has been less than in the past and withdrawal of waters using 34 dams including Farakka in the upstream does have a significant impact on Bangladesh and its economy. If this situation continues, 37% (area wise) and one-third of the population of Bangladesh will face a critical situation in the coming decades. Probable climatic change may also aggravate the hydrological effects.
In order to keep the Ganges system alive, Bangladesh should have undertaken the construction of the proposed Ganges Barrage, which would help us to save water to be used during dry season. In addition, the Joint River Commission should play an active role to monitor the guaranteed water flow stipulated in the 1996 treaty.
Management of the large amount of sediment deposited by this river should also be taken into account in order to save people and agricultural lands from persistent water-logging, which has become a common phenomenon in Jessore and Sathkira region due to siltation in the river beds.
Since India agreed to consider Bangladesh's claim on water resources during the recent visit of Bangladesh's prime minister in New Delhi, we should keep demanding our due share according to the 1996 treaty. If we fail to maintain continuous flows in the Ganges system, it will be really impossible for us to save the environment and ecosystem of the entire south-west region of Bangladesh, including the largest mangrove forest of the world, the Sundarbans.
Dr. Ashraf Dewan is Associate Professor, Department of Geography & Environment, University of Dhaka.
Email: dewan1971@gmail. com
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