delta
Delta, the estuary alluvial plain, is a common surface topography. Rivers and rivers in the coffees of the sediment and other impurities, encountered in the sea salt water is much higher than the fresh water, condensed silt deposition, and gradually become the new wetlands of the estuary, and then the formation of the delta plain. The top of the delta points to the upper reaches of the river, the outer edge facing the sea, can be seen as the triangle "bottom". The term "delta" is translated from English. English delta is the transfer of Greek Δ. Greek meaning derived from the shape of the delta like "Δ" (triangle), some people think that this is the letter "Δ" pictographic origin. ...