Excessive salinity in river water threatens ecology in S region

BARISHAL, Apr 20:  Excessive salty-water is entering localities through the Meghna's Chandpur point in the southern (S) region.
The salinity-blended water is being driven by sea tide in the absence of low flow of water from the Meghna and trans-boundary rivers in the upstream. With the salinity submergence, ecological balance is being threatened.
According to field sources, the salty-water enters with the Bay of Bengal's tide in downstream of the Meghna in Chandpur  crossing 100 kilometres of the upstream in Barishal.
In the Kirtarnkhola River flowing beside Barishal, salty-water has arrived with a double-per cent level of salinity.
On condition of anonymity, water experts said, the excessive salinity is the bad-warning for normal environment. They blamed the inadequate rainfall for low water flow from the upstream rivers.According to the Water Development Board (WDB) data, by  January  in 2006,  the salinity-limit in the Kirtankhola River  was 610-630 per cent per million PPM; the salinity percentage increased to 910 PPM in 2017; it made an improvement in 2018, but again started to increase to end with 900 PPM in 2019.
In the last year (2000), the limit of salinity was about 900 PPM in January.
The WDB sources said, by December last, levels of salinity in rivers of the southern region started increasing.
From the last month, it has started to become worse.  With beginning of the current month, the salinity exceeded the normal level in the Kirtankhola by 1,000 PPM, according to more than one sources.
River experts said, sea-bound flow of 54 trans-boundary rivers including the Padma are declining; Bangladesh is being deprived of right shares of these rivers; and ultimately, upstream flows of these rivers in the locations of Bangladesh are losing normal shedding.
In the last month, the rainfall was short by about 80 per cent in the country; it was 99.5 per cent in Barishal, and 94.2 per cent in Rajshahi.
In March last, the rainfall in Barishal was only 0.03 millimetre  against the normal requirement of 53 per cent. There was no rainfall in Barishal  in January.  By February, the rainfall was only one millimetre.
In more than one locality in the southern region, croplands are being destroyed due to salinity. During the last full-moon tide, tidal water of the Bay of Bengal crossed Barishal to reach downstream in Chandpur.
The salty-water is not only damaging croplands, but also destroying forest and fisheries in coastal areas, experts said. According to them, there is no alternative to increasing flow of rivers in the upstream on an urgent basis.