探索频道英语听力 消失的法老城市08

Manfred Bietak was interested in the role played by the Nile in ancient times when he stumbled upon the strange truth about Piramesse. He was trying to trace the lost river beds and waterways of the Nile in order to map out what the Delta would have looked like at the time of the Pharaoh.
Today, there are only two branches of the Nile in the Delta. But we know that in the past , the river branches have switched course many times. Through history, the Nile would have had different branches all across the Delta. Branches that have long ago dried up and disappeared. The reason for this is that each branch of the Nile in the Delta carries so much silt from upstream that its river bed keeps building up until the water can no longer flow through it. At that moment, the river branch will switch course, finding a new route down to the sea and carving out a new path, sometimes far away from the old river bed.
The only way to trace these ancient waterways is to study a contour map. All lost rivers leave telltale signs in the contour lines on maps, signs that an expert can trace to find the ancient path of the old dried-up river.

By studying these contour lines , Bietak finally came up with a single map, charting every ancient silted-up branch and waterway of the Nile through the eastern Delta. There were many lost channels, and each had been active at some time in the past 5,000 years.

On this reconstruction map , with the help of the study of the contours of the Delta landscape, I was able to reconstruct the variety of Nile branches in antiquity.

This one map held the truth about Piramesse, because it would reveal where the city should lie. The ancient texts said it lay on the Delta's easternmost branch.So all Bietak had to do was to work out which was the easternmost branch of the Nile at the time of Ramesses the Great. To do that, he had to date all the ancient branches, and he did that with pottery.

In Egypt, cities and settlements were built along active branches of the Nile which supplied them with drinking water, sanitation and transport. Like all ancient settlements, Piramesse's busy streets and markets would have left behind tons of rubbish. Above all, potterry.