As a result, the steep increase of volume may overflow the river, if it is unable to deal with it quickly enough. These rivers will bring silt, which will again slow down the flow of the water. .
The Ganga has a very unreliable and complex regime, meaning that the levels of water entering the river cannot be reliably predicted and it therefore is prone to sudden unexpected increased input, while at other times there may be little input. Normally, during the months of July and October rainfall can vary from 650mm to 2000mm within this region. This is as a result of the monsoon season: Bangladesh may go many months with little rain but then will experience periods of sudden heavy rainfall. The river is forcedto deal with these sudden increases in the volume of water entering the river, and at times is simply incapable or coping with such. This unregular input of water, leaving the river instead to deal with sudden deluges of water means it simply cannot cope and flooding occurs. There is no reliable way of predicting the rainfall, or when it will come, and so it is difficult to make preparation. Much of the discharge comes s a result of the snowfall in the mountains, and this can flunctuate, again proving to be unreliable. As a result, the river is often subjected to irregular inputs of water to the extent that the rivers cannot cope with the sheer volume, or carry it's increased load.
From the three main rivers feeding into the Ganga basin inevitably seem to reach their peack discharge levels at the same time, and this synchronisation of their main flooding times has a massive knock-on effect. If each one peaked at different times of the year the river may have a better chance of coping effectively and the risk of flooding would be reduced, but this is not the case and as a result the discharge levels in lower Bangladesh will reach high levels, as they did during the floods of 1988, when the resultant flooding was extensive.
