基于投入产出方法的甘肃省水足迹及虚拟水贸易研究

随着社会化进程的加快,地处西北内陆的甘肃省正面临日益严峻的水资源短缺危机,社会经济发展受到一定程度的制约,水生态环境也呈现出恶化的趋势。水足迹是近年来提出的衡量人类活动对于水生态系统影响的指标,能够帮助决策者制定水资源管理及保护的政策,从而实现地区水资源的可持续利用。运用单区域投入产出方法计算并分析了甘肃省1997、2002和2007年第一产业、第二产业和第三产业部门的虚拟水强度、水足迹以及虚拟水贸易情况。结果显示:(1)甘肃省第一产业的虚拟水强度最高,但呈现出逐年下降的趋势,水足迹也因此有所下降;(2)虚拟水贸易方面,甘肃省以虚拟水净出口为主,尤其是第一产业,每年虚拟水净出口量约全省总水资源量的10%。建议甘肃省继续巩固已有的节水成果,调整产业结构,大力发展节水型产业和高新技术产业。同时建议适当调整贸易格局,合理控制虚拟水出口,以缓解当地水资源短缺危机,保障地区水安全与生态安全。     

三江平原粮食作物生产水足迹时空特征及影响因素

水足迹是评价人类活动对水资源开采和水环境污染程度的重要方法,对农作物生长过程的绿水足迹、蓝水足迹和灰水足迹进行量化和分析,可以为农业用水综合评价和用水管理提供指导。以三江平原为研究区域量化粮食作物生产水足迹的时空特征,揭示粮食生产对区域水资源的占用情况,并分析水足迹的影响因素。结果表明:(1)三江平原粮食生产水足迹总量在2005-2018年间呈显著增加趋势,其中绿水足迹、蓝水足迹和灰水足迹在水足迹总量中的占比历年平均为28%、8%和64%;(2)粮食生产水足迹空间差异明显,在地市尺度,佳木斯市水足迹最高,占三江平原总量的47%,在县区尺度,富锦市、依兰县和桦南县是水足迹热点地区;(3)只考虑蓝水足迹,粮食生产给三江平原水资源造成轻度压力,而同时考虑蓝水和灰水足迹,粮食生产给三江平原水资源造成重度压力;各地市间水资源压力有较大差异,其中佳木斯市负担了该区域将近一半的粮食产量,水资源压力最高,鹤岗市则水资源压力最低;(4)降雨量、灌溉水利用效率、化肥施用量、粮食种植结构和作物单产水平等都会影响粮食作物生产水足迹,其中蓝水足迹响应种植结构的变化最敏感,灰水足迹响应化肥施用量的变化最敏感,而水足迹总量响应作物单产水平的变化最敏感。因此,建议减少化肥施用量、提高作物单产水平和优化作物种植结构纳入区域水资源可持续管理之中。     

Virtual water and water footprints do not provide helpful insight regarding international trade or water scarcity

Many authors have estimated the virtual water content of good and services traded internationally, and many have calculated national water footprints that account for the volumes of virtual water imported and exported. Some authors have suggested that international trade of virtual water has been harmful to selected exporting countries with limited water endowments. Some suggest also that current patterns of international trade should be rearranged to make better use of global water resources. Yet, countries do not actually trade in virtual water. They trade in goods and services for which water is one of many inputs. Wise choices regarding water resources and smart strategies regarding international trade cannot be determined by focusing on water alone. The notions of virtual water and water footprints are not helpful indicators of optimal strategies regarding water resources, particularly when considering issues such as water scarcity or international trade. I describe four perspectives regarding virtual water and water footprints, with the goal of demonstrating the inadequacies of these notions in policy discussions and in efforts to determine the optimal allocation and use of water resources. The four perspectives are: (1) international trade should not be modified or regulated to reflect the virtual water content of traded commodities or water footprints in the countries of trading partners, (2) countries do not save water by engaging in virtual water trade, (3) consumers in one country cannot alleviate water scarcity or improve water quality in other countries, and (4) water footprints are not analogous to carbon or ecological footprints.     

飞来峡水库水质现状及其向广州供水能力的探讨

水库供水(特别是对城市的供水)已成为缓解全球水资源供给不足的重要途径。于2001年至2003年的丰水期和枯水期调查分析了新建河流型水库-飞来峡水库的水质、浮游植物群落特征和营养状态。结果表明飞来峡水库水质良好,多数水质指标为地表水Ⅱ水质标准,其营养盐浓度、浮游植物的密度均较低,属于贫中营养。从近几年的水质变化来看,建库后,水质改善明显。通过对广州市饮用水源水水质现状及存在问题的分析,从水质和水量两方面探讨了飞来峡水水库作为广州优质水源地的优势。由于来水量大,水库水质净化能力强,飞来峡水库水质和水量均有保证,可作为广州市重要水源地之一。但今后,在流域管理和水土保持工作更应重视和加强。     

A simple approach to assess water scarcity integrating water quantity and quality

Water scarcity has become widespread all over the world. Current methods for water scarcity assessment are mainly based on water quantity and seldom consider water quality. Here, we develop a simple approach for assessing water scarcity considering both water quantity and quality. In this approach, a new water scarcity index is used to describe the severity of water scarcity in the form of a water scarcity meter, which may help to communicate water scarcity to a wider audience. To illustrate the approach, we analyzed the historical trend of water scarcity for Beijing city in China during 1995–2009. The results show that Beijing made a huge progress in mitigating water scarcity, and that from 1999 to 2009 the blue and grey water scarcity index decreased by 59% and 62%, respectively. These achievements were made through great efforts of water-saving measures and wastewater treatment. Despite this progress, we demonstrate that Beijing is still characterized by serious water scarcity due to both water quantity and quality. The water scarcity index remained at a high value of 3.5 with a blue and grey water scarcity index of 1.2 and 2.3 in 2009 (exceeding the thresholds of 0.4 and 1, respectively). As a result of unsustainable water use and pollution, groundwater levels continue to decline, and water quality shows a continuously deteriorating trend. To curb this trend, future water policies should further decrease water withdrawal from local sources (in particular groundwater) within Beijing, and should limit the grey water footprint below the total amount of water resources.     

Effects of slightly acidic electrolysed drinking water on mice

Slightly acidic electrolysed (SAE) water is a sanitizer with strong bactericidal activity due to hypochlorous acid. We assessed the safety of SAE water as drinking water for mice at a 5 ppm total residual chlorine (TRC) concentration to examine the possibility of SAE water as a labour- and energy-saving alternative to sterile water. We provided SAE water or sterile water to mice for 12 weeks, during which time we recorded changes in body weight and weekly water and food intakes. At the end of the experiment, all of the subject animals were sacrificed to assess serum aspartate aminotransferase, alanine aminotransferase and creatinine levels and to examine the main organs histopathologically under a light microscope. In addition, we investigated the bacteria levels of both types of water. We found no difference in functional and morphological health condition indices between the groups. Compared with sterile water, SAE water had a relatively higher ability to suppress bacterial growth. We suggest that SAE water at 5 ppm TRC is a safe and useful alternative to sterile water for use as drinking water in laboratory animal facilities.     

基于ESTDA模型的中国水生态足迹及水生态压力评价

基于水足迹视角,测度了中国31个省份2000-2018年的水生态足迹广度、深度及水生态压力,采用ESTDA框架对其时空动态特征进行分析。结果表明：①研究期内,中国水生态足迹总量呈波动上升态势;水生态承载力波动幅度较大,空间分布格局整体呈现自东南向西北逐渐较少的趋势。②水生态足迹广度与水生态承载力呈同步变化趋势,整体上已接近水资源可提供的流量资本上限,各省市水生态足迹深度差异较大。③研究期内,水生态压力指数小于1的区域与水生态足迹深度为1的区域相吻合,水生态压力指数大于1的区域主要分布在华北及西北地区。④LISA时间路径表明,水生态足迹广度、深度及水生态压力的整体空间格局均具有较强的稳定性;三者的局部空间结构在空间依赖方向上的稳定性依次加强;空间格局演化的空间整合性呈现水生态足迹深度 > 水生态压力 > 水生态足迹广度,空间上,水生态足迹广度正向协同增长省份主要集中于南方省份,而水生态足迹深度和水生态压力正向协同增长区则分布于华北、西北地区;各要素的空间分布格局表现出较强的路径依赖及锁定特征。     

China’s water footprint by province,and inter-provincial transfer of virtual water

Water shortages and the uneven distribution of water resources restrict China’s sustainable development. The concepts of virtual water and water footprints provide a new approach to alleviate regional shortages of Chinese water resources by the inter-provincial allocation of commercial water resources. In this study, an interregional input-output model was applied to quantitatively estimate the water footprint of each province in China and to quantify the inter-provincial transfer of virtual water. The results indicated that there was considerable diversity in the water footprints of the various provinces. Provinces with larger populations and greater GDP had larger water footprints, and developed regions had higher proportions of external water footprints. From the perspective of final demand, local consumption was the main factor driving the water footprints of these provinces. From the perspective of sectoral structure, the agricultural water footprint had a larger proportion in these provinces. The transfer of virtual water in China did not occur from regions with abundant water resources to those suffering from water shortages, but it generally occurred from west to east, from inland to coastal areas, and from underdeveloped to developed regions. Many water-deficient regions also had large net virtual water exports. Water shortages in China will be alleviated by the enhancement of industrial water-use efficiency in water-deficient regions, the transfer of water-intensive industries to regions with abundant water resources, and the development of tertiary industries with low water consumption.     

Water structure changes induced by ceramics can be detected by increased permeability through aquaporin

Aquporins are intrinsic membrane proteins that function as water channel to transport water and/or mineral nutrients across biological membranes. In this study, we aimed to clarify whether water structure can be changed by the presence of ceramics and whether such a change can be determined by aquaporin. First, we confirmed that ceramics could transform tap water into active tap water by increasing water permeability through aquaporin. We also found that this change in water permeability by treatment with ceramics occurred in distilled water. The distilled water was determined to exhibit the same aquaporin permeability as the original tap water. Our data indicate that the aquaporin permeability of water can be changed by severe physical shocks, such as slapping and sonication, which is consistent with the implication that the aquaporin permeability is closely related to the structure of the water. In this study, using aquaporins, we first reported that the treatment of water with ceramics can affect the structure of water, and the water can retain the structure for a given period under certain condition     

Foliar water uptake: Processes,pathways, and integration into plant water budgets

Nearly all plant families, represented across most major biomes, absorb water directly through their leaves. This phenomenon is commonly referred to as foliar water uptake. Recent studies have suggested that foliar water uptake provides a significant water subsidy that can influence both plant water and carbon balance across multiple spatial and temporal scales. Despite this, our mechanistic understanding of when, where, how, and to what end water is absorbed through leaf surfaces remains limited. We first review the evidence for the biophysical conditions necessary for foliar water uptake to occur, focusing on the plant and atmospheric water potentials necessary to create a gradient for water flow. We then consider the different pathways for uptake, as well as the potential fates of the water once inside the leaf. Given that one fate of water from foliar uptake is to increase leaf water potentials and contribute to the demands of transpiration, we also provide a quantitative synthesis of observed rates of change in leaf water potential and total fluxes of water into the leaf. Finally, we identify critical research themes that should be addressed to effectively incorporate foliar water uptake into traditional frameworks of plant water movement.     

基于多区域投入产出分析的京津冀地区虚拟水核算

通过贸易与消费调控实现区域水资源优化配置已成为缓解地区水资源压力的途径之一。跨区域投入产出分析可为地区间虚拟水贸易战略提供依据。基于2012年京津冀地区投入产出表与生产用水量构建了跨地区虚拟水核算模型,计算了隐含在经济贸易中的虚拟水总量及各地区各部门的直接用水系数、完全用水系数和拉动系数,分析了各部门虚拟水进出口情况,识别了重点耗水部门。结果表明:京津冀地区呈现虚拟水净出口状态,其中净出口部门主要为北京的服务与交通业,河北的农业和制造业。京津冀的农业、矿业和水供应业在生产过程中直接消耗水量大,应注重提升用水效率及节水技术的开发;三地制造业、建筑业和服务与交通业的平均拉动系数较大,这说明其他部门生产活动对该部门依赖性较大,其单位产出的提高将带动整个地区更多虚拟水量的投入。此外,河北的农业和制造业为京津冀各部门输送了大量虚拟水,为各部门生产提供了支撑,是节水的重点部门,应着重调整其产业结构,并从直接和间接用水两方面入手减少水资源消耗。计算了京津冀地区不同部门的直接、间接水资源消耗、水资源消耗拉动系数,以及部门间的虚拟水贸易情况,结果可为该地区部门间水资源配置和虚拟水战略的制定提供基础。     

Water resources stress assessment and risk early warning–a case of Hebei Province China

In most parts of China, water resources development and utilization has reached or exceeded the international warning level, especially in the northern arid and semi-arid regions, the serious water stress have aroused worldwide concerns. Many issues of water resources are closely and some inseparably associated with human activities. In this study, the water footprint (WF) and related indicators were applied as comprehensive indicators to assess real water use by humans from the consumption perspective. A Fuzzy Comprehensive Evaluation Model (FCE) was used for the evaluation in its role to assess water stress. And the index system of water stress assessment including four aspects, namely water supply and demand balance, socio-economy, agricultural production and ecological environment was established. Taking the case of Hebei province of China where there is serious conflict between water supply and demand, water stress assessment of all eleven administrative areas for the period 2000–2013 was analyzed. The findings showed that water stress was denoted by three levels, namely high water stress (red zone), general water stress (yellow zone) and low water stress (blue zone), which lays the foundation of the further research on water risk warning. According to the results of water stress assessment and the socio-economic development trends of Hebei, a Markov Chain Risk Warning model was built to describe the risk state of water system and to predict the transition probability of future states. This was intended to focus on the possibility that water stress levels might change into higher water stress level. The current study aims at extending earlier research by making a first step from water footprint estimation towards water stress assessment and providing reference for scientific management of water resources in arid and semi-arid regions.     

水足迹研究进展

水为生命之源,水资源的合理分配与科学管理是区域可持续发展与流域综合管理的核心环节;水足迹作为一种全面核算人类活动对水资源真实占用的综合指标,将人类消费终端与水资源利用密切关联,为维护流域水资源安全、提高区域水资源利用效率提供了重要的科学依据,已成为当前国际水资源管理的前沿研究领域。在明确水足迹及水资源生态足迹相关概念的基础上,对比分析了水足迹与生态足迹、水资源生态足迹模型的异同,明晰了过程、产品及区域等不同研究对象的水足迹核算方法,系统梳理了产品和区域水足迹评价、基于水足迹的区域水资源安全研究、区域水足迹可持续性分析等水足迹主要研究内容的近今进展,并展望了进一步的重点研究方向,即水足迹综合研究、水足迹评价不确定性分析、水足迹与物质流核算的关联研究,以及基于足迹整合的可持续发展多维测度等。     

内陆河干旱区生态需水分析

根据水分驱动生态演变模型 ,以水分运动和补给条件 ,研究了内陆河平原生态系统的需水结构。生态需水分为过渡带生态需水 ,绿洲生态需水 ;绿洲生态需水又进一步分为天然绿洲生态需水和人工绿洲生态需水。通过流域水分平衡和地面观测资料确定了生态圈层结构的水分需求 ,以及降水与径流对水分需求的补给比例。生态需水的分析计算 ,类似于供需平衡分析。从植物生理角度分析生态需水 ,得到天然植被的总腾发量 Et,作为植被生态需水总量。各典型天然植被的 Et通过实验资料获得。将植被和水面的总生态需水量扣除有效降水补充的部分 ,即为径流性生态需水量 GE。另一方面 ,以流域为单元进行降水和径流统一考虑的水分综合平衡 ,进行生态可利用水量分析。得到生态系统可能实际利用的径流性水资源量 GR。　　将生态需水量 GE与生态系统可能实际利用的水资源量 GR进行平衡分析 ,计算实际生态耗水 ,并分析盐碱地无效耗水。根据 2 0 2 0年生态状态情景分析 ,作出了 2 0 2 0年生态需水与生态系统结构演变的预测     

A comprehensive analysis of blue water scarcity from the production,consumption, and water transfer perspectives

The issue of growing water scarcity has been increasingly perceived as a global systemic risk. To solve it, an integrated approach considering different perspectives of water scarcity is at a premise. In this study, we developed an approach to calculate the blue water scarcity (BWS) and integrated the production, consumption, and water transfer perspectives into a single framework. The results are as follows: The average BWS in the Hetao irrigation district was 0.491 during the 2001–2010 year period, which was much larger than the threshold of 0.30, indicating a high water stress level. From the production perspective, the agricultural sector was the largest contributor to regional water scarcity and the average BWS was as high as 0.479. From the consumption perspective, BWS related to virtual water export was much larger than that related to water consumption for making products to be consumed locally and the values were 0.422 and 0.069, respectively. Under the influence of physical and virtual water transfer, BWS changed from 0.242 (medium to high water stress level) to 0.491 (high water stress level). Strategies for reducing agricultural water consumption, such as increasing crop water productivity, improving irrigation efficiency, and promoting more reasonable irrigation water price, could be adopted in the Hetao irrigation district to alleviate regional BWS. Compared with physical and virtual water import, the virtual water export played a more important role in influencing the regional water scarcity, and the increase in crop water productivity, decrease in crop export volume, or adjustment of trade pattern from water-intensive crops to water-extensive ones could be feasible measures to decrease virtual water export for lower water stress, while the trade-offs in the product-consuming regions should be considered.     

基于水足迹理论的煤制油产业布局评价

煤制油是我国应对石油危机的重要途径之一,但其高耗水的特点使其备受争议。利用水足迹理论对全国五大煤炭基地2015年规划的煤制油产业进行了蓝水足迹和灰水足迹的测算,分析了煤制油产业对这些区域水资源的耗用情况及冲击程度。结果显示,神东、晋东和新疆伊犁3个基地的煤制油产业蓝水足迹超过了1亿t、灰水足迹超过了3亿t,其中神东地区作为最大的煤制油产地两项数值分别达到1.9亿t和4.1亿t与当地水资源总量对比,宁东地区煤制油耗水冲击最大,占当地水资源总量的28.2%;新疆伊犁地区比例最小,为0.36%。通过对这5个煤炭基地以区域为尺度的水足迹结构分析和评价比较,得出了两种煤制油工艺的水资源消耗差异,并且为煤制油产业在五大基地的合理布局给出了依据,与此同时为接下来煤制油产业的技术革新和流程优化也提出了相应的建议。     

不同生育期玉米叶片光合特性及水分利用效率对水分胁迫的响应

利用大型移动防雨棚开展了玉米水分胁迫及复水试验,通过分析玉米叶片光合数据,揭示了不同生育期水分胁迫及复水对玉米光合特性及水分利用效率的影响。结果表明:水分胁迫导致玉米叶片整体光合速率、蒸腾速率和气孔导度下降以及光合速率日变化的峰值提前;水分胁迫后的玉米叶片蒸腾速率、光合速率和气孔导度为适应干旱缺水均较对照显著下降,从而提高了水分利用效率,缩小了与水分充足条件下玉米叶片的水分利用效率差值;在中度和重度水分胁迫条件下,玉米叶片的水分利用效率降幅低于光合速率、蒸腾速率和气孔导度的降幅, 有时甚至高于正常供水条件下的水分利用效率;适度的水分胁迫能提高玉米叶片的水分利用效率,从而增强叶片对水分的利用能力,抵御干旱的逆境;水分亏缺对玉米光合速率、蒸腾速率及水分利用效率的影响具有较明显滞后效应,干旱后复水,光合作用受抑制仍然持续;水分胁迫时间越长、胁迫程度越重,叶片的光合作用越呈不可逆性;拔节-吐丝期水分胁迫对玉米叶片光合作用的逆制比三叶-拔节期更难恢复。     

两种荒漠生境条件下泡泡刺水分来源及其对降水的响应

泡泡刺通常以灌丛沙堆的形式存在,具有很强的生态适应性,在防风固沙、抗旱耐盐等方面具有独特的功能,但是水分条件仍然是限制其生存和发展的关键因素.为了明确泡泡刺在不同荒漠生境条件下的水分利用策略,研究了河西走廊临泽绿洲边缘沙质和砾质生境下泡泡刺的水分来源季节动态特征以及对不同降雨事件的响应程度.测定了两种生境下泡泡刺茎水和不同水源(降水、土壤水和地下水)的氧稳定同位素(δ¹⁸O)值,结合IsoSource模型计算了不同水源对泡泡刺水分来源的贡献比例.结果表明:两种生境下泡泡刺茎水δ¹⁸O值及其水分来源都存在显著的季节变化特征,沙质生境下泡泡刺在降水较少的春季和秋季主要利用地下水,其贡献率可达50%以上;而砾质生境下的泡泡刺无法利用深达11.5 m地下水,其水分来源受降水控制,具有较大的季节变异性.两种生境下的泡泡刺对降水响应显著,但是降水过后,随着土壤含水量的快速减小,沙质生境下的泡泡刺转而以丰富的地下水为主要水分来源,而砾质生境下的泡泡刺只能利用降水入渗至较深层土壤的较少水分.因此,两种生境下泡泡刺不同的水分利用策略是导致其生长特征差异的主要原因,同时也表明泡泡刺具有较强的自我调节和适应能力.     

Attraction of slimy sculpins to chemical cues of brook charr eggs

In a laboratory study to examine the responses of slimy sculpin Cottus cognatus to chemical cues of brook charr Salvelinus fontinalis eggs, water that held freshly laid eggs (<20 min old), water-hardened eggs (i.e. eggs >4 h old) or injured eggs was collected and used in a series of two-choice tests. Slimy sculpin were exposed to paired stimuli of (1) hard egg water v . control water, (2) fresh egg water v . control water, (3) hard egg water v . injured egg water or (4) hard egg water v . fresh egg water. Sculpin spent considerably more time on the side of the tank with hard egg water and fresh egg water v . control water and injured egg water v . hard egg water. Sculpin did not show a preference for hard egg water v . fresh egg water. In a field study, brook charr were attracted to chemical cues from brook charr eggs, suggesting that brook charr eggs produce sufficient odour to attract some species under natural conditions.     

Community Water Improvement,Household Water Insecurity,and Women’s Psychological Distress: An Intervention and Control Study in Ethiopia

BackgroundOver 650 million people worldwide lack access to safe water supplies, and even among those who have gained access to ‘improved’ sources, water may be seasonally unreliable, far from homes, expensive, and provide insufficient quantity. Measurement of water access at the level of communities and households remains crude, and better measures of household water insecurity are urgently needed to inform needs assessments and monitoring and evaluation. We set out to assess the validity of a quantitative scale of household water insecurity, and to investigate (1) whether improvements to community water supply reduce water insecurity, (2) whether water interventions affect women’s psychological distress, and (3) the impacts of water insecurity on psychological distress, independent of socio-economic status, food security, and harvest quality.ConclusionThese results contribute to the construct validity of our water insecurity scale, and establish our approach to measuring water insecurity as a plausible means of evaluating water interventions. Improvements to community water supplies were effective in reducing household water insecurity, but not psychological distress, in this population. Water insecurity was an important predictor of psychological distress. This study contributes to an emerging literature on quantitative assessment of household water insecurity, and draws attention to the potential impact of improved access to water on women’s mental well-being.