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 一项全国性调查显示，如果当地水土仍以当前速度流失的话，中国大西南将有约1亿人在35年内失掉他们赖以生存的土地。
这项60年来最大规模的调查发现，在中国约三分之一的国土上，粮食作物与水利保障正因为风与水对泥土的冲蚀而受到威胁。
按现有趋势，中国最大的粮产地东北地区的粮食产量将在50年内下降40%，而中国13亿的人口却将继续增长。
专家们认为，受到水土流失影响的三分之一国土多为耕地与林地，而组织这次调查的研究小组却发现工业用地与城市和偏远地区一样正受到水土流失的威胁。中国每年流失的土壤高达45亿吨，仅仅在最近10年里便已造成了2000亿人民币的损失。
中国水土流失与生态安全综合科学考察委员会花了整整三年完成了这次调查，他们撰写的报告指出，受水土流失威胁最大的将是贫困人口。而中国近四分之三的贫困人口生活在水土流失影响的地区。
受到影响的还有中国的80000余座水库，由于泥沙堆积，它们的库容正不断减少。河流的淤积和水库的库容减小使得洪水的危险大大增加。
水利部部长陈雷对官方报纸《人民日报》说：“如果我们不采取有效措施治理水土的话，中国的社会与经济发展将受到很大的影响。”
中国官方通讯社新华社则报道说中国总计有超过350万平方公里的土地面临水土流失的威胁，其中160万平方公里受到的水的冲击，另外200万平方公里土地则受到风的吹蚀。
中科院水土保持研究所教授穆兴民告诉《卫报》记者说，人口的过度增长是水土的问题的主要原因。他说，他通过对东北地区过去25年的分析发现了人口密度过高的影响。
新的公路与铁路建设也加重了这一问题，而且在中国人们也缺乏其它国家那样的环保意识，他补充说。
穆教授以受到水土问题影响最大的黄河流域为例说，“黄河在历史上因为含沙量高于其它河流而因颜色而得名，但如今人类活动让黄河变得更黄了。”
中国政府很多年来一直非常重视北方草原的沙漠化问题，也因90年代末造成长江流域大洪水的过度砍伐问题而开始对伐木问题严加管理。穆兴民说，为了恢复林地与草原我们要做的还有很多，他还说，如果人类想要某些地区完全恢复的话，就必须退出这些地区。
原文：
Soil erosion threatens land of 100m Chinese, survey findsCrops and water supplies are suffering serious damage as earth is washed and blown away Sediments discharge into the Bo Hai Bay and western Yellow Sea colouring the surface waters caramel in this satellite view of China. Light brown hues show bare land, darker browns areas of vegetation. Photograph: Modis/Nasa
Almost 100 million people in south-west China will lose the land they live on within 35 years if soil erosion continues at its current rate, a nationwide survey has found.
Crops and water supplies are suffering serious damage as earth is washed and blown away across a third of the country, according to the largest-scale study for 60 years.
Harvests in the north-east, known as China's breadbasket, will fall 40% within half a century on current trends, even as the 1.3 billion population continues to grow.
While experts cited farming and forestry as the main causes, contributing to over a third of the area affected, the research team said erosion was damaging industrial areas and cities as well as remote rural land. About 4.5bn tonnes of soil are scoured away each year, at an estimated cost of 200bn yuan (£20bn) in this decade alone.
The poor will be worst hit, warns the report from China's bio-environment security research team, which worked on the survey for three years. Almost three-quarters of them already live in erosion-hit areas.
The country's 80,000 reservoirs are also affected, with sand and mud reducing their storage capacity each year. Like soil deposits along rivers, that increases the risk of flooding.
"If we don't conduct effective measures, erosion will cause major damage to social and economic development," Chen Lei, the director of the Ministry of Water Resources, told the official People's Daily newspaper.
The state news agency Xinhua said more than 3.5m square kilometres were affected in total, with 1.6m square kilometres scoured by water and 2m square kilometres by wind.
Professor Mu Xingming of the Institute of Soil and Water Conservation told the Guardian that overpopulation was largely to blame. He said his analysis of north-east China over the last century showed the effects of increasing population density.
New roads and railways were also contributing to the problem and people were less aware of the need for environmental protection than in other countries, he added.
Mu cited the Yellow River as one of the areas worst hit. "Historically, it got its name because of its colour - because the water contains more mud and sand than other rivers. But now it's yellower because of human activities," he said.
Beijing has been concerned about the desertification of China's northern grasslands for many years, and scaled back logging after deforestation contributed to flooding along the Yangtze in the late 1990s. Mu said more work was needed to restore forests and grasslands and suggested humans would have to leave some areas entirely if they were to recover.
[ 本帖最后由 DeGaulle 于 2008-11-26 12:23 编辑 ] |
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发表于 2008-11-24 18:59:49