死海正在消失吗 Is the Dead Sea dying?

Is the Dead Sea dying?
死海水位正不断下降未来可能干涸



相关报导:
德国达姆施塔特科技大学的研究人员沙赫拉扎德·埃布·吉哈兹尔赫和同事们认为，死海的水位正伴随着严重的环境污染以惊人速度下降，如果这一趋势得不到遏制，死海干涸不是没有可能。

　　因此，正在计划中的死海到红海或地中海到死海的人工水道需要有非常大的流量，才能把足够的水送到死海，让它再次达到以前的水位，并可以持续地发电，通过脱盐产生淡水。最近发表在《自然科学》上的研究报告指出，死海水位下降不是气候变化所致，一定程度上是由人们对水的需求越来越大造成的。

　　死海等封闭湖泊的水位通常反映出气候状况，水位由流入死海的河水、直接降雨量和蒸发掉的水量决定的。而就死海来说，水位发生变化是由约旦人对水的需求越来越大、约旦河支流雅木克河用于灌溉以及以色列和约旦钾肥业对死海水的使用造成的。

　　这项研究发现，在过去30年里，耗水量不仅导致死海水位下降，还使其容量和表面面积快速减少。沙赫拉扎德和同事们发明了一个有关死海表面面积和水容量的模型，发现死海在过去30年里失去了14立方千米的水。他们研究了死海的侵蚀阶地，首次用“差分全球定位系统”(DGPS)精确记录了相关数据。他们还确定了侵蚀阶地的具体年龄。

　　研究人员指出，死海水位下降会造成许多不利后果，例如工厂用死海的水提取碳酸钾；盐和镁所需的成本会大大提高；周边地下水层的淡水快速流出；出现大量污水池；脱盐形成的泥浆，它们严重危害着公路和土木工程建筑。

　　为了解决死海水资源所承受的越来越多的压力和由水位降低造成的环境危害，研究人员建议可以把其他地区的水引到死海地区，减少当地脱盐的海水量，这样就可延缓死海水位下降的速度，同时为建造红海到死海或地中海到死海的水道争取时间。

美国物理学家组织网上的英文原文:

The water levels in the Dead Sea - the deepest point on Earth - are dropping at an alarming rate with serious environmental consequences, according to Shahrazad Abu Ghazleh and colleagues from the University of Technology in Darmstadt, Germany. The projected Dead Sea-Red Sea or Mediterranean-Dead Sea Channels therefore need a significant carrying capacity to re-fill the Dead Sea to its former level, in order to sustainably generate electricity and produce freshwater by desalinization. The study, published online this week in Springer's journal, Naturwissenschaften, also shows that the drop in water levels is not the result of climate change; rather it is due to ever-increasing human water consumption in the area.

Normally, the water levels of closed lakes such as the Dead Sea reflect climatic conditions - they are the result of the balance between water running into the lake from the tributary area and direct precipita-tion, minus water evaporation. In the case of the Dead Sea, the change in water level is due to intensive human water consumption from the Jordan and Yarmouk Rivers for irrigation, as well as the use of Dead Sea water for the potash industry by both Israel and Jordan. Over the last 30 years, this water consumption has caused an accelerated decrease in water level (0.7 m/a), volume (0.47 km³/a) and surface area (4 km² /a), according to this study.
Abu Ghazleh and colleagues developed a model of the surface area and water volume of the Dead Sea and found that the lake has lost 14 km3 of water in the last 30 years. The receding water has left leveled sections on the lake's sides - erosional terraces - which the authors recorded precisely for the first time using Differential Global Positioning System (DGPS) field surveys. They were able to date the terraces to specific years.
The authors point out that this rapid drop in the level of the Dead Sea has a number of detrimental con-sequences, including higher pumping costs for the factories using the Dead Sea to extract potash, salt and magnesium; an accelerated outflow of fresh water from surrounding underground water aquifers; receding shorelines making it difficult for tourists to access the water for medicinal purposes; and the creation of a treacherous landscape of sinkholes and mud as a result of the dissolution of buried salt which causes severe damage to roads and civil engineering structures.
To address the mounting stress on water resources in the Dead Sea basin and the environmental ha-zards caused by its lowering, the authors suggest that the diversion of Jordan water to the Mediterra-nean coast could be replaced by desalinization of seawater, causing the recession of the Dead Sea to be considerably slowed, and buying time to consider the long-term alternatives such as the Red Sea-Dead Sea Channel or the Mediterranean-Dead Sea Channel.
The authors conclude that either of these channels will require a carrying capacity of more than 0.9 km3 per year to slowly fill the lake back to its levels of 30 years ago and to ensure its long-term sustai-nability for energy production and desalinization to fresh water. Such a channel will also maintain tour-ism and potash industry on both sides of the Dead Sea.