... rainfall and runoff, the tides and the depth of bars in the sea in front of the estuaries. Otherwise, in early rainy season, nearly 1,6 million hectares of the delta are infected by the acidity ... In the 5 months of the wet season, from May to October, the river discharges 2/3 the total annual flow. The rest amount of river flow is distributed in 7 months, from November to May, of the ... nutrients for agriculture cultivation but they are one of the drinking water treatment problems also. The sediment load of the river isnot so high if compared with Red river in the North of Vietnam....