<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区
          US EUROPE AFRICA ASIA 中文
          China / View

          Groundwater shortage calls for urgent action

          By Asit K. Biswas and Kris Hartley (China Daily) Updated: 2017-04-13 06:56
          Groundwater shortage calls for urgent action

          China's decision to relocate Beijing's non-capital functions to Xiongan New Area, which is home to Baiyangdian Lake, the largest freshwater body in North China, highlights the acute water shortage Beijing faces. This calls for special attention to the groundwater shortage.

          China has 20 percent of the world's population but less than 6 percent of the groundwater. The overstressed North China aquifer serves 11 percent of the country's population, 13 percent of its agricultural production, and 70 percent of its coal production. The measures to solve China's water problems have so far been inadequate. The massive South-North Water Transfer Project has supplied Beijing with 2 billion cubic meters of Yangtze River water a year since 2014, but is not a long-term solution, say some Chinese scientists.

          Desalination could be another solution. In coastal areas near Beijing, restrictions on extraction of groundwater for industrial use have been imposed to force desalination into the supply portfolio, but desalinated water has not been incorporated systematically into the municipal water systems. The resultant dependence on and over-extraction of groundwater are having severe impacts on Beijing, including subsidence. Long Di, a researcher at Tsinghua University's Institute of Hydrology and Water Resources, says: "Subsidence is a slow but progressive disaster, and it is irreversible. It can cause cracks in walls, roads, bridges, and underground municipal infrastructure."

          The problem is particularly acute in Chaoyang district, which borders Beijing's eastern suburbs - areas that are rapidly expanding with dense, high-rise buildings. In San Francisco, California, the case of a new luxury 57-floor building leaning several degrees only years after construction, due to poor foundation standards, illustrates the legal, financial and social challenges of building in areas with geo-technical instability. What makes the problem more challenging is that many buildings in Beijing's rapidly subsiding districts are far taller.

          Water conservation is dependent as much on individual decisions as on national policymaking. One example is California's 2015 water shortage. California Governor Jerry Brown called for a statewide reduction in water usage of 25 percent in July 2015, and the state exceeded expectations by reducing usage of 31 percent. Much of this reduction came from changes in personal habits; fewer people watered their lawns and washed cars. California also encouraged municipalities to actively manage demand, and many imposed surcharges on individual users who exceeded stipulated limits. Indeed, academic studies have shown pricing to be a powerful water demand management tool.

          China's demand profile for water does not closely resemble California's; both markets have high usage for agriculture (64 percent in China and 80 percent in California), but China's manufacturing activity as a share of economic output is larger than California's.

          China must adopt a more aggressive volumetric pricing program, however, to manage demand, particularly for industrial users. On a per cubic meter basis, water tariffs on businesses and individuals are less than 12 percent those in Denmark and less than half of those in the developed world. China's implicit subsidization of water serves little purpose, least of all in prompting conservation and innovation.

          China has made some efforts to address these challenges. The sponge-cities program, a modified version of low-impact development that focuses on permeable surfaces and water infrastructure, seeks to increase groundwater absorption. The central government has set a target for 80 percent of Chinese cities to meet sponge-city standards by 2030. This is a crucial step in aggressively addressing groundwater depletion in urban areas, including Beijing.

          However, there appears to be a tepid appetite for private investment in these projects. More aggressive inducements are needed to prompt public-private partnerships for sponge-city development. Addressing the groundwater depletion problem - and in broader measure the growing crisis of water scarcity amid rapid urbanization - will require a multi-pronged approach that includes unequivocal political will, transparency regarding the impacts and costs of depletion, creative policy initiatives to manage demand, and support for technical innovations to improve usage efficiency. Both China's economic and environmental sustainability are at stake.

          Asit K. Biswas is distinguished visiting professor at the Lee Kuan Yew School of Public Policy, National University of Singapore, and Kris Hartley is a lecturer in the Department of City and Regional Planning, Cornell University.

          Highlights
          Hot Topics

          ...
          主站蜘蛛池模板: jizzjizz日本高潮喷水| 亚洲av永久无码精品秋霞电影影院| 免费无码中文字幕A级毛片| 国产免费人成网站在线播放| 国产亚洲另类无码专区| 亚洲区一区二区三区亚洲| 日韩av在线一区二区三区| 亚洲国产精品一二三四五| 亚洲一区二区三成人精品| 四虎成人精品永久网站| 高中女无套中出17p| 一区二区久久精品66国产精品| 欧美在线观看www| 青柠影院免费观看高清电视剧丁香 | 国产精品不卡一区二区视频| 激情五月开心综合亚洲| 狠狠色噜噜狠狠狠狠888奇米| 色综合久久中文综合久久激情| 韩国无码AV片在线观看网站| 伊人色婷婷| 国产亚洲中文字幕久久网| 中文字幕乱码亚洲美女精品| 国产不卡一区二区三区视频| 亚洲韩欧美第25集完整版| 国产中文字幕久久黄色片| 国产综合久久亚洲综合| 色噜噜av男人的天堂| 四虎库影成人在线播放| 欧美日韩国产三级一区二区三区 | 亚洲一区二区经典在线播放| 18禁亚洲一区二区三区| 狠狠色噜噜狠狠狠狠色综合久| 亚洲伊人久久大香线蕉av| 国产一区二区不卡在线视频| 亚洲人成网站在小说| 亚洲国产精品高清久久久| 中文字幕在线精品人妻| 色妞永久免费视频| 丰满的少妇一区二区三区| 亚洲av无码专区在线亚| 丝袜老师办公室里做好紧好爽|