从第二届世界水资源论坛看辽宁的水资源危机及对策

辽宁是我国重要的工业省份 ,境内分布着我国三大城市群之一 ,农业也很发达 ,工农业生产、城市建设和居民生活对水资源的需求量都很大。本文根据第二届世界水资源大会有关会议资料[4 ] 及后续影响 ,从世界范围内水资源的分布、取用和污染现状与发展趋势[6,9] ,对辽宁省水资源危机进行分析 ,对其今后宜采取的有效措施进行建议与论证。1　第二届世界水资源论坛的简要回顾“第二届世界水资源论坛”是 2 0世纪末和 2 1世纪初水资源领域一次最重要的会议。在世界水资源委员会的组织下 ,在荷兰交通与公共事务及水资源管理部、荷兰住房与空间规划及…     

基于民族生态学视角的哈尼梯田农业生态系统水资源管理

作为山地农业的典型模式之一,哈尼梯田以其悠久历史和文化景观成为世界文化遗产和全球重要农业文化遗产。哈尼梯田农业生态系统的成功之处在于有效的水资源管理,但对其制度建设和生态文化内涵的综合分析尚待完善。基于民族生态学视角,结合生态学、民族学等自然科学和社会科学的理论与方法,对哈尼梯田水资源管理的制度建设及其生态文化内涵进行解读。研究表明,哈尼族社区通过以涵养和分配为核心的水资源管理制度建设完美地解决了水资源时空分布不均这一难题,而以迁徙文化、宗教文化、习惯法以及传统知识为支柱构建的生态文化体系则是保障水资源管理制度建设和有效实施的生态文化内涵。哈尼梯田水资源管理的制度建设与生态文化理念对于应对气候变化、促进农业可持续发展以及完善我国的水资源管理制度理论体系具有重要的借鉴价值。     

一种改进的中国水资源空间网格化方法

为揭示中国水资源的时空分布格局,引入降水量、干燥度、蒸散发、坡度、植被覆盖度、集水区等6个因素,结合分区权重赋值法,提出了一种改进的对中国水资源空间分配模型。结果表明:基于二级流域的改进水资源空间分配模型对我国具有较高的适用性,其中在三级流域和省级行政单元上的空间分配总体误差分别为7.89%和7.25%。相比黄河流域、淮河流域和西北诸河流域,长江流域、松花江流域和东南诸河流域的水资源空间分配精度更优,其原因在于该区域的水资源空间分布受自然因素(降水量、蒸散发等)影响更为显著。中国水资源空间分布从西北到东南呈增长趋势,这与降水的空间格局基本吻合。南方诸河流域的水资源量主要来源于降水,而冰川融水则是西北诸河流域及多数内陆河流域的主要水源。水资源与国内生产总值(GDP)密度之间的关系随城市规模和地理位置发生变化。这些可为区域水资源管理提供科学依据和数据依据。     

我国水资源生态足迹分析与预测

生态足迹模型的提出为水资源可持续利用的定量评价提供了新思路.通过构建水资源生态足迹和水资源生态承载力的计算模型,对我国1949～2007年水资源的可持续利用状况作出了客观的评价,并运用ARIMA模型对我国水资源生态足迹变动趋势作出深入的研究.结果表明,1949～2007年,我国人均水资源生态承载力总体上呈下降态势,而人均水资源生态足迹则逐年上升,从而造成人均水资源生态赤字逐渐增大,我国水资源处于一种不安全状态.运用ARIMA(2,1,3)模型的预测结果表明,2008～2012年,我国人均水资源生态足迹将继续呈上升态势,水危机形势将日益严峻.在此基础上,针对我国水资源的可持续利用问题提出了一组政策建议.     

水资源生态足迹计算方法

Wackernagel创立的生态足迹模型是一种较好的评价可持续发展与利用的方法,但是在该模型中,仅评价了的地表水域的渔业功能,忽略了地下水和地表水作为水资源的其他功能.分析生态足迹模型及水资源的特点后,在其理论框架下设立水资源帐户,并阐述了该帐户的内涵,建立了水资源生态足迹以及水资源生态承载力的计算模型,确定了计算水资源帐户生态足迹所需的3个关键参数即全球平均水资源产量、全球均衡因子和地区产量因子,按水资源利用的一般分类对水资源帐户进行了细分.通过利用该模型对江苏省1998～2003年水资源生态足迹的计算,结果表明,计算结果可以客观的评价江苏省水资源可持续发展与利用的情况,证明了模型的正确性和科学性,从而弥补了生态足迹模型的不足.     

黑河流域水资源承载能力分析

黑河流域属资源性缺水地区,区域水资源难以满足当地社会经济发展和生态平衡的需要.随着西部大开发战略的逐步实施,西北干旱内陆河地区水资源的支撑作用将显得愈来愈重要.因此分析黑河流域水资源现状条件下对区域经济、社会发展的承载能力,显得极为重要.根据黑河流域具体情况,结合流域经济社会发展特点、生态环境状况,以遏制并逐步改善流域生态环境为基本前提,以流域水资源承载能力为约束.首先利用水资源承载压力指数计算了现状条件下黑河流域水资源承载压力度,得出目前黑河流域水资源承载能力属于超负荷承载.水资源将成为制约黑河流域社会经济发展和保证生态平衡的重要因素.当前必须立足于当地的水资源条件,按照以供定需的原则,合理安排生活、生产和生态用水,才能实现流域经济社会和生态环境的协调和可持续发展.然后针对超载现状,对黑河流域规划水平年（2010年）水资源承载能力作进一步的分析评价,根据相关预测资料设计了3种可能情景,利用流域评价的发展系数、协调系数、公平系数和可持续发展系数,从水资源开发利用方式、社会发展方式、经济发展模式、生态恢复程度等方面分析水资源承载能力,并计算其水资源承载压力度,同时结合水资源的可持续发展建立流域可持续发展评价指标体系,进行方案组合和各种发展模式的水资源优化配置.满足流域水资源支撑经济社会可持续发展判据的方案的承载能力指标即为该方案下的水资源可持续承载能力指标. 通过对黑河流域现状及规划水平年的水资源承载能力及可持续发展度分析评价,利用水资源可持续发展战略分析,选取出了最优发展模式,为流域的可持续发展提供了基本依据.通过寻求情景方案中水资源承载能力和可持续发展度的最佳组合,实现了经济、社会与生态的可持续发展目标.结果表明：通过努力,谋求经济和社会与水资源承载能力协调发展是有可能实现的.     

我国极端干旱天气变化趋势及其对城市水资源压力的影响

随着全球气候变化和水循环的改变,降水不均和持续干旱等极端天气事件的频度和强度增加,对水资源,尤其是人口和社会经济密度高的城市的水资源带来很大的影响和压力。为了探究我国干旱天气的变化趋势、区域特征、及其对城市水资源压力的影响,采用全国917个气象站点1951—2014年的逐日降水量数据集,分析了我国水资源及干旱的变化趋势和空间分布特征,并以我国289个主要地级市为研究对象,构建了气候变化情境下的城市基于区域降水禀赋的水资源压力评估方法,预测并展望了不同时段和不同代表性浓度路径(RCPs)情景下的未来城市水资源压力的情况。结果显示,我国极端干旱情况整体是随着全球气候变化增加的,年最长连续无降水天数变化速度的平均值为2.3d/100a,但是具有区域性,具体表现为南部地区干旱减缓而北部地区干旱严重。我国城市水资源压力受水资源禀赋的影响,呈现北方高而南方低的分布,除此之外水资源消耗大的大城市资源压力也比较大。随着气候变化,近期我国整体城市水资源压力相对现阶段增加了2%左右,具体水资源压力上升的城市有170个,水资源压力减少的城市有110个,剩下的9个城市水资源压力受气候变化的影响比较小。在低应对的RCP8.5情景下的城市水资源压力远远高于在RCP2.6情景,这说明减缓气候变化工作对降低我国城市水资源压力有积极作用;城市水资源压力的变化并不是均匀的,呈现南部减少而北部增加的变化趋势,我国华北地区城市的水资源压力最大,随着气候的变化,该地区的水资源压力也在随着时间不断增加,需要政府积极行动,提出有针对性和前瞻性的水资源规划方案,并依据方案采取措施,以应对气候变化造成的城市干旱增加。     

中国生态地理区城市水资源利用效率时空分异特征

我国水资源面临的形势十分严峻，水资源短缺、水污染严重、水生态环境恶化等问题突出，已成为制约社会经济可持续发展的主要瓶颈。基于分类数据包络分析（Categorical DEA）对2007-2016年中国生态地理区城市水资源利用效率进行测算，对其时间变化、空间分布以及空间收敛性进行分析。结果表明：1）2007-2016年期间全国城市水资源利用效率总体处于低效率状态，随时间高低交错波动式发展，整体呈先降后升势态；2）生态地理区城市水资源利用综合效率由高到低依次为温带干旱区、温带半干旱区、温带半湿润区、温带湿润区、亚热带湿润区，呈西北向东南逐渐递减的空间分布格局，生态地理区纯技术效率区间差异较大，但空间分布规律不显著，区域规模效率间差距小，且无明显空间分布规律；3）纯技术效率低效是制约全国水资源利用综合效率提升的主要因素，生态地理区间纯技术效率巨大差距导致全国纯技术效率整体低效，也是全国水资源利用综合效率低效的根本原因；4）生态地理区水资源利用综合效率区域差距逐渐缩小，主要是因为高效率区域效率值向低效率区域靠拢，区域间低效向高效的"追赶效应"不明显。     

基于流域尺度的甘肃省水资源承载力评价

资源承载力是评价水资源状况的重要指标, 基于流域尺度研究水资源承载力可为水资源规划管理、经济社会发展与人民生活提供参考依据。为得到更加符合实际的评价结果, 从水资源、居民生活、社会经济、生态环境等4个方面选取14个指标, 采用博弈论组合赋权法确定指标权重, 利用TOPSIS综合分析法对甘肃省2009—2018 年水资源承载力进行分析评价, 并对省内7个二级流域分别进行了水资源承载力评价。结果表明: (1)2009—2018 年甘肃省水资源承载力有升有降, 存在波动现象, 其中2012年承载力最强, 综合评价值为0.371, 处于略强承载状态; 2015年最弱, 为0.627, 处于略弱承载状态, 其余年份均处于均衡承载状态; (2)甘肃省水资源承载力在空间分布上总体表现出南强北弱的特点; (3)为增强甘肃省水资源承载力, 满足水资源可持续利用, 建议细化水资源管理方案、加大水利设施的建设强度、推进流域间水资源调度的实施、实施更为合理且有效的水资源配置方案, 以实现水资源的合理规划与管理。     

水资源利用与保护的途径--流域管理

为了促进水资源的利用与保护 ,美国率先提出了流域管理 ,目前是水资源管理的主要模式 ,在世界上得到了广泛应用。在描述流域管理的萌芽、发展历程、目标、基本思想的基础上 ,介绍了国内外先进的技术手段和国外流域管理的成功典范———美国流域保护规划和澳大利亚全流域管理方法。我国水资源质量现状表明 ,我国目前水资源缺乏有效管理 ,流域管理尚未贯彻到水资源管理的全过程中 ,存在较多问题。为了完善流域管理 ,加强非点源污染管理、流域评价、土地利用规划和完善相关法律是当前的主要任务。只有从我国流域管理现状出发 ,把流域管理作为水资源利用与保护的主要途径 ,才能做到水资源的可持续发展。     

Water,Water, Everywhere

Abstract

Math and Science Across Culture: Activities and Investigations from the Exploratorium. Maurice Bazin, Modesto, and the Exploratorium Teacher Institute. New York: The New Press, 2002. 176 pp. $19.95 (paperback). ISBN 1-56584-541-2

History Beneath the Sea—Nautical Archaeology in the Classroom. K. C. Smith and Amy Douglass (Editors). Washington, D.C.: Society for American Archaeology, 2001. 28 pp. $5.95 (paperback). ISBN 0-932839-17-7.     

节水应优先于调水

就规划中的南水北调西线工程受水区情况,本刊记者访问了刘昌明院士和陶传进博士。尽管他们对南水北调西线工程的必要性看法不同,却表达了一个共同的声音：受水区应把挖掘自身的节水潜力摆在优先。     

Water

Water remains a scarce and valuable resource. Improving technologies for water purification, use and recycling should be a high priority for all branches of science.One of our most crucial and finite resources is freshwater. How often do biologists spare a thought for this substance, other than to think about its purity for the sake of an experiment? How often do we consider that 30 litres of cooling water are used to make one litre of double-distilled water? Americans use approximately 100 gallons per person per day, whereas millions of the world''s poor subsist on less than 5 gallons per day. Within the next 15 years, it is estimated that more than 1.8 billion people will be living in regions with severe water scarcity, partly as a result of climate change. By 2030 it is estimated that the annual global demand for water will increase from 4,500 billion m³ to 6,900 billion m³—approximately 40% more than the amount of freshwater available (Water Resources Group, 2009). We are not only facing an increasing scarcity of water, but we also misuse the available water. Approximately 2.5 billion people use rivers to dispose of waste—not to mention what industry dumps into them—while freshwater dams generate problems of their own including population displacement, the spread of new and more diseases to people living in the vicinity of the river, as well as effects on ecology and farming downstream.Many factors influence the supply of and demand for water, and a one-fits-all solution for all regions is therefore not possible. There are essentially two strategies to ensure a sound supply of freshwater: we either use less water, or we make more of the water that we do use. The first is a typical accounting approach and is limited in scope, whereas the second calls for better science and engineering approaches.Although the surface of the Earth is mostly covered with water, more than 95% of it is salty or inaccessible. One clear solution to increase fresh water supply is desalination, which can be done by distillation or osmosis, through the use of carbon nanotubes, or by using another promising new technology: biomimetics. Water can be filtered through aquaporins—proteins that transport water molecules in and out of cells. Such biotechnologies could reach the market as early as 2013, although other exciting technologies are already available. Simple chemistry can be used, for example, in the ‘PUR'' water purifier that uses gravity to precipitate water-born contaminants and pathogens or the water purifier akin to a trash bag, which cleanses water through a nanofibre filter containing microbicides and carbon to remove pollutants and pathogens. Such simple and cheap technology is ideal for billions of the world''s poor who do not have access to clean drinking water.Of the available freshwater, agriculture uses the largest share—up to 70% in many regions—and technological and biotechnological solutions can also contribute to preserving water in this context. New farming processes that can retain water in the soil, recycle it or reduce its use include no-till farming, crop intensification, improved fertilizer usage, crop development, waste water re-use and pre- and post-harvest food processing, among many others. The different degrees of water quality can also be exploited for agriculture; ‘grey water''—which is unsafe for human consumption—could still be used in agriculture.In addition to improving management practices, there is no question that we need considerably more innovation in water technology to close the supply–demand gap. These developments should include better processes for purification and desalination, more efficient industrial use and re-use and improved agricultural usage. The problem is that the water sector is poorly funded in all respects, including research. New technologies could help to re-use water and reclaim resources from wastewater while generating biogas from the waste. There is also enormous potential for the use of water beyond its consumption in households, agriculture and industry. ‘Blue energy'', for instance, generates power from reverse electrodialysis by mixing saltwater and freshwater across an ion exchange membrane stack. This could potentially generate energy wherever rivers flow into the sea.With so many innovations already under way with so little funding, what other technologies can we come up with to reduce water usage and deal with medical, industrial and individual waste? The issue of waste is a serious and pressing problem: we find pharmaceutical chemicals in fish, which are in turn consumed by humans and other species in the food chain. We need to find ways to effectively transform waste into biodegradable products that can be used as fertilizers, as well as to recover valuable molecules such as rare metals. The downstream consequences of such technologies will be the regeneration of coastal estuaries, lower levels of contaminants in marine life and cleaner rivers. Ultimately, we need much more research into reducing water use, purification, bioremediation and recycling. I submit that this should be a priority research area for all the natural sciences and engineering.Companies are held accountable these days for socially responsible projects, sustainability and their carbon footprint—this includes water usage. Why should research institutions not be held responsible too? After all, we claim to be at the cutting edge of science and should set the trend. Research grants should have a ‘green component'' and a score should be given to applications according to water usage and ‘green work''.     

Water Biophysics: How Water Interacts with Biomolecules

The papers of this special issue are based on a Conference on Water Biophysics and develop a fundamental understanding on how water interacts with biomolecules. The Conference highlighted the great empathy of a multidisciplinary and integrated approach to rationalize the role of water in foods, pharmaceutical, and biochemical systems, taking vantage of the advances in simulation and experimental methods.     

Matric Bound Water of Water Tissue from Succulents

Matric bound water was measured as water retained by frozen and thawed tissue after desorption on a pressure membrane filter under 20 bars nitrogen gas pressure. Central water-storage tissue and peripheral chlorenchyma from leaves or stems of 15 taxonomically diverse non-halophytic succulent species were investigated. Matric bound water as a per cent of the dry weight averaged higher in water storage than in chlorenchyma tissue but lower than values reported for many mesophytic leaves. Matric bound water as a proportion of the total water held, however, was lower in water tissues. Osmotic potentials were generally high (solute contents low). It is concluded that matric or osmotic forces cannot account, in any unique way, for the high water content of water tissues. This appears to depend, instead, on the enormous ability of the thin-walled cells to take up available water and expand.     

Grafham Water

SUMMARY. The phytoplankton and zooplankton of Grafham Water reservoir, Cambridgeshire, are described and discussed for the 5 years 1974–78 together with the main physical variables and macro-nutrients believed to affect them. This follows on from the Water Pollution Research Laboratory study of 1969–74. The rationale for the work was to provide short-term warning of treatment and management problems caused by algae and to gain insight into the factors controlling them.
During the period reviewed the 1976 drought occurred with a massive draw-down. Afterwards replenishment of the lake from the River Great Ouse resulted in its enrichment with high concentrations of nitrate, orthophosphate and silica. The algal cycles changed to some extent over this period with a few species becoming even more dominant and others diminishing in importance. The effect of the drought and post-drought pumping is discussed; a return to former nutrient levels seems likely. The effects of weather, particularly radiation and wind, on algae may be of equal importance to nutrient levels in Grafham and will be further investigated.