48. The Rivers of the Delta. 



By F. D. Ascoli. 



Almost a century and a half have elapsed since Major 

 Rennell commenced his survey of the rivers of Eastern 

 Bengal, and in so young a country, where the century yields to 

 the decade as the measure of antiquity, it is not unnatural to 

 suppose that nature should afford some striking examples of 

 change due to fluvial action. I do not mean to imply that 

 within this space of time the wider laws of potamology can be 

 proved by actual evidence of change. — changes due to the 

 natural raising of the levels of the banks and the beds of rivers 

 and to diminution in the slope of the deltaic lands. I would in 

 fact hazard the suggestion that such changes, which I would 

 describe as the strategy of river action, are not of paramount 

 importance in so young an area ; it is the tactics of river action 

 the changes due to the natural oscillation of rivers and the 

 tendencies which cause them to cut their banks and depart 

 from their original courses, which alone can be traced out in 

 so short a period — the smaller and more intricate changes which 

 largely condition the execution of the wider laws. It is these 

 less general laws which are seen at work in the actual delta, 

 laws which appear to supersede the wider principles. Granted 

 that the slope of the delta is gradually diminishing owing to the 

 large deposits at the mouth of the Meghna, the change is never- 

 theless so small that its effect is incalculable in the stretch of 

 river from Goalundo to the sea. Granted again that in the 

 older lands of the actual delta, e.g., the south of the Dacca 

 district and the Palang thana of Faridpur, the river banks are 

 considerably higher than the interior, still the changes are due 

 to the actual cutting of these high banks; the high bank is not 

 a permanent feature. It may be admitted that there are 

 instances of the raising of a river's bed, as in the S. Dacca 

 rivers, e.g., the Issamutty; but one is compelled to acknowlege 

 that these changes are due to external causes, that the rivers 

 in question are dying rivers which can point to no new course 

 to compensate for the loss or shrinkage of the old. The two 

 main factors of change are the cutting bank of the river and 

 the formation of new chars, not throughout the bed of the 

 river, but in some specific place. There are three means by 

 which these changes may be followed out : 



(a) Local Information.— -This requires very careful sifting 

 owing to the tendency to exaggeration and mythologization 

 if I may use the word. 



(6) Old Maps and Papers.— This is a mine of much value 



