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“透支生态”加重自然灾害

去年舟曲致命的泥石流是人类发展造成自然灾害的一个深刻教训,蒋高明报道。

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2010年是中国自然灾害频发的一年,先是西南五省大旱,继之长江上游洪涝危害,后是甘肃舟曲泥石流,然后东北地区洪灾。自然灾害频发,灾害天气固然是重要原因,然而不能忽视的是,人类长期蔑视自然,“透支”自然生态“成本”,才造成了自然灾害频率加大、危害加重。试以甘肃舟曲泥石流为例说明一下。

舟曲县本是“陇上江南”,这里原有丰富的森林资源和水资源,土地和气候资源也不错。然而,在贡献了几百亿立方米的林木,建造了成百上千个水电站后,舟曲已是童山濯濯,有水也保不住了。

先来看森林破坏。舟曲县境内植物资源丰富,仅高等植物就达1300多种,原有林业用地291万亩,占全县土地面积65%,其中森林面积123万亩,森林覆盖率45%,高于甘肃省平均水平(7.5%),也高于全国平均水平(22%)。遗憾的是,舟曲县境内的森林,经过30多年的采伐,遭到了巨大破坏。上世纪70年代,平均每年采伐木材就达8万立方米。乱砍、乱伐、倒卖、盗运木材,使全县森林资源每年以10万立方米的速度逐年减少。

泥 石流发生后,记者在舟曲三眼峪沟大峪、小峪两个沟看到,山上的树木几乎看不到了,灌木也十分稀疏。而据老人们回忆,他们十几岁的时候,峪口往里到处都是粗 大的树木。森林破坏后,山地裸露,在加上村民放牧山羊,生态破坏更加严重。没有了森林植被保护,那些处于陡坡山的土壤和大小石块,就容易在暴雨来临时,借 助重力作用危害山下人们们的生命和财产安全。

再来看建水电站的影响。作为嘉陵江上游的最大河流,白龙江长约600公里,其中甘肃境内450公里。河道穿行于山区峡谷,天然落差大,水流湍急,水电部门自然看好了这样的水利条件,于是,大量修水电站,较少考虑上游生态退化、泥石流易发。整个白龙江地区处在多个地震带交汇处,地质结构非常复杂,修建水电站、沿岸采矿,更加重了土壤松动。

沿白龙江每条支流行走,都会看到建立的大大小小的水电站。相关资料和专家实地考察证实,白龙江两岸共建有上千座水电站,这些水电站装机容量不等,大的在20~30万千瓦左右,小一些的则为0.5~0.6万千瓦,而更多的是几百千瓦的小型水电站。从上世纪70年代至今,白龙江都在修建水电站,几乎与森林砍伐同步进行。

修建水电站与生态保护常常发生矛盾,在实施“天然林保护工程”区域内的大型水电站是侵占森林后结果,那些最初规划、或是已经成型的林地,在修建水电站时常被破坏,而林业部门交涉的结果常常不理想。由于大部分水电站是通过招商引资而来的,有当地政府的批文、有环境评价报告,因此在“林水之争”过程中摩擦不断,最终是生态让位给水电开发。

从2003年至2007年,舟曲共有53个水电开发建设项目签订合同,其中41个水电开发建设项目已建成或在建,另外12个马上就要开展前期工作,这些水电开发建设项目占全县各类开发建设项目的80%以上。据估计,上述41个在建或已建的水电站工程合计弃渣达3834.8万立方米,水土流失预测量达74.9万吨。修建水电站后,山体被水浸泡松软,水电站附近随时都会发生滑坡。另外,修建水电站挖沙使整个河床上弃满了乱石,一旦发生暴雨,这些石头会被洪水裹挟,形成巨大的杀伤力。

三是侵占河道。尽管泥石流、滑坡灾难已经引起了当地人警惕,但城市规划缺失、河道乱占、乱建甚至抢建、交钱就建的现象并没因大自然的警告而停止。舟曲地方狭窄,两山夹一江,整个盆地仅12平 方公里。数十年来人口增长,而在地域面积无法增加的前提下,所能挤占的地方只有河道了。三眼峪沟和罗家峪沟河道是舟曲县城惟一能够扩张的地方,开发商就在 那里买地盖房,一些人在河道里建起了小洋楼。此次洪水经过的月圆村、东街村和东关村等人口密集的地方,恰是河水流经的地方,那里的房地产业曾经火爆过。

舟曲县一卖山,二卖水、三卖河道,最终酿成泥石流灾难,这是全国生态灾难的一个缩影。今年1~7月全国共发生地质灾害2.6万起,是去年同期的近10倍; 全国共发现地质灾害隐患点20万处,在云南、贵州、四川、重庆、甘肃、陕西、湖南、湖北等山多坡陡的省市,类似于舟曲的特大型和大型地质灾害隐患点数以万计。

有钱人的“金山银山”,不如老百姓的青山绿水。当环境灾难来临的时候,受害的是当地老百姓,舟曲之痛,实乃为生态环境之痛,我们不能再干那些为经济增长而牺牲生态环境和人民群众生命财产的傻事了。


蒋高明,中国科学院植物研究所首席研究员

首页图片来自SFTHQ

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dengdeng

舟曲能卖什么?

作者说“舟曲县一卖山,二卖水、三卖河道”。我们很多学者一味批评当地破环环境,忽视可持续发展,能不能也给当地提出一些发展的建议。

如果一个地方连发展都无从谈起,一旦有了机遇,谁还在乎那是可持续的还是不可持续的?就这一点来说,首先大城市就做了坏榜样。他们有更多发展的选择和机会,但也没把环境当回事儿。像一些只能依靠环境发财的地方,哪有那么高的觉悟为未来着想。

How can Zhouqu make a living?

The author says that "Zhouqu exploited its mountains, its water and its rivers." All a lot of our academics do is criticise locals for destroying the environment, while overlooking sustainable development. How about coming up with a few suggestions for how the area could develop?

If somewhere doesn't know where to start developing then as soon as there is an opportunity they will take it, without caring if it is sustainable or not. On this point, the large cities are a bad example. They had greater choices and opportunities to develop, but still they chose not to consider the environment. In places where the only route to riches is through their environment, who would have the vision to think of the future?

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meter

是的,这是整个社会的导向问题

作者写的没错,我相信是给所有考虑未来而非眼前利益的智者们一个思考改过的提醒,而非指责某个个体,希望每个地球的子民都尽起保护自己的家园的责任啊!

Yes, it's a society-oriented matter

The author is right. I believe it is not censure to a certain individual but a reminder to wise people, who consider the future rather than immediate interests, to reconsider and correct mistakes. I hope everyone on the earth shoulder the responsibility to protect our own homeland!

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cdhelennh

not convinced

我理解的本文作者是植物学家。但他的一些论断,我认为得让水利或山地灾害专家来做或引用这些学者的研究,会显得更有说服力。
比如,“在云南、贵州、四川、重庆、甘肃、陕西、湖南、湖北等山多坡陡的省市,类似于舟曲的特大型和大型地质灾害隐患点数以万计”;还有“修建水电站后,山体被水浸泡松软,水电站附近随时都会发生滑坡。”等等。
我不是搞自然科学研究的,但最近接触到一些研究,比如在地震断裂带上的岷江水电开发就是很有地方特色的。该河流上游的很多水电站都不是拦坝蓄水式的,而是凿洞引流,即把整个山体凿空,水流利用山体落差在洞内装机发电。这和拦坝式的水电对地质山体的危害是不同的,不知道哪一种对当地山体危害最大。
可能是中外对话的篇幅限制吧,蒋专家并没有展开,但如果有更多合适的文献应该注明一下供读者深入学习。

not convinced

I understand the author is a botanist. But I think, for some of his conclusions, he has to let water or mountain disaster experts conduct research or should refer to research done by these scholars, since this will make his arguments more convincing.

For example, “Tens of thousands of [geological risk points] lie in mountainous provinces such as Yunnan, Guizhou, Sichuan, Chongqing, Gansu, Shaanxi, Hunan and Hubei and have the potential to unleash disaster on the scale of Zhouqu.”; and “On completion of a dam, water soaks the hillsides and loosens the earth, creating a situation where landslides could happen at any time,” and so on.

I’m not engaged in natural science research but recently came upon some studies, like one that revealed the construction of hydropower stations along an earthquake fault zone on the Min River takes into account many local conditions. Many hydropower dams along this river’s upper reaches don’t obstruct water flows, but are more like drainage holes. The entire mountain acts like a drain, with installations inside crevices able to generate power from water flowing over the mountain. The geological hazards of this method of producing hydropower differ from those for dams that block the flow of water, and I don’t know which type is the most damaging to local mountains.

Perhaps Chinadialogue is constrained by space, so the points raised by the expert, Mr. Jiang, are not very developed. But if there is more appropriate literature out there, ChinaDialogue should indicate this so readers can look more deeply into the topic.

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tdeanxx

水电站及大坝诱发地震活动

蒋的文章谈到了在林区及山区建立水电站的环境代价,但却并未提及2008年四川大地震与紫平铺大坝之间的可能性关联。科学家对两者之间的联系已经有过争论,但作为一个地球物理学家,我想说的是,这个致使数千人失去生命,五百万人流离失所的巨大灾难很有可能与这个地震有关联。地壳活跃地带的断裂层往往十分接近断裂点,而临近断裂带的坝体填筑致使蓄水压力突变可能引发断裂带的突然断裂,即便该区域可能长期处于非地震活跃区。人们所讨论的四川断裂带距离紫平铺大坝只有1公里,在地震爆发的几个月内一直是蓄满水的。去年,我对这个地方进行了视察,可以肯定地说大坝本身没有坍塌已是不幸中的万幸,否则洪水可能席卷成都,三峡大坝可能遭遇击溃。这是一个很重要的例子,也显明了在开发地形复杂的山区中科学判断人类及自然环境代价的重要性与艰巨性。

Hydro-power and Dam Induced Seismicity

Jiang’s article touches on the environmental costs of hydropower in forested, mountainous areas, but didn’t mention the likely connection between the Zipingpu dam and the great Sichuan earthquake of 2008. The connection has been debated by scientists, but as a geophysicist, I would say that this great disaster that killed thousands and left five million homeless very likely can be linked to the quake. Faults in tectonically active areas are always very near the rupture point, and a sudden change in the hydrological pressure due to a dam filling near a fault can cause the fault to fail abruptly, even if it has been seismically inactive for long periods of time. The Sichuan fault in question passed within a kilometer of the Zipingpu dam, which was filled to capacity within months of the earthquake. I visited the area last year and can say with some certainty that it is extremely fortunate that the dam itself did not fail, possibly leading to the flooding of Chengdu and the overwhelming of the Three Gorges Dam. This is an important example of the importance and difficulty of scientifically determining the human and environmental costs of development in complex mountainous regions

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匿名 | Anonymous

hi

this was super helpful!!!!!!☺☻♥