灌溉威尼斯，可以嗎？

意大利威尼斯這個浪漫水鄉正受著下陷沉沒的威脅，科學家表示，以現時的下陷速度估計，位於舊城區的威尼斯古蹟將於2050年永遠消失於亞德里亞海。考古學家的研究指出自建以來，這個古都便以每世紀十厘米的速度下陷，但二十世紀的工業開發，把大量的水源抽走，以至過去一百年裡，威尼斯下陷了二十三厘米。為了拯救這座建築在古老礁湖上的城市，Padua大學工程系教授Giuseppe Gambolati提出了泵水計劃，將海水深深注入這座城市所依託的岩石裏，把這座城市的地面提升三十厘米，防止城市被海水吞沒。在這項爲期十年的工程中，每年有望將一千八百萬立方米的澄淨海水注入地下。這些海水將以六百米至八百米之間的深度泵入到沙岩石層裏，這些岩石將膨脹，提升它上面的地面和城市以及建築物的高度。威尼斯城政府正對這項創新的建議進行詳盡的可行性研究 。

Archaeological evidence proves that Venice is sinking at a rate of around 10 cms per 100 years, but in the last century, it lost an extra 10-13 cms due to industry pumping water out of the deep aquifers. Although this process was stopped in the 1970s, the damage was done, and in many parts of the city, the water at high tide is above the stone foundations of the buildings and laps against the porous brickwork, causing it to crumble away. It is estimated that by the year 2050, the historic portion of Venice will be permanently lost under the Adriatic Sea. A proposal by Padua University to raise Venice 30cm by pumping water back into the soil is now under planning. The idea is to pump water down 700 meters, using 12 bore holes around a circumference of 10 km. Giuseppe Gambolati, professor of engineering at the University of Padua, who has been studying the subsoil of the Adriatic since 1972, says, "we have calculated that if we pump in 18 million cubic meters of clean sea water 24 hours a day for 10 years, we will raise Venice 30cm." A pilot project will now begin, at a cost of 15 million Euro, to see how a square kilometre, perhaps a small island, behaves over three years of pumping.

Photo Credits:
Small_canal_-_Venice.jpg A small canal in Venice, by Jerome Herr.
Photo: Navigation markers in the Venetian Lagoon.