广东省水资源特点和合理开发利用研究

本文论述广东水资源量,时空分布和季节变化特点,并分析广东用水存在问题,不合理开发利用水资源和浪费水;水库蓄水和调节能力未能满足用水要求;水质污染日渐严重。使水资源渐感紧缺。按目前用水趋势,要达到供需水平衡,必须成立统一管理水资源的流域机构;按不同的经济发展阶段,改变其主要洪水职能;节约用水;增加水库的供水和调节能力;改变调峰发电方式：提高重复用水率;保护水质;做好水土保持工作。最后提出,制定地方经济发展总体规划时,其用水量必须与可能供水量相适应。     

北京市水足迹及农业用水结构变化特征

运用水足迹的理论和方法计算评价了1990—2005年北京市水足迹及水资源利用的可持续性,在此基础上进一步分析了北京市农业用水结构的变化特征。结果表明:(1)北京市水足迹从1990年的81.5亿m3上升至2005年的168.6亿m3,人均水足迹由750.1m3上升为1096.0m3;(2)北京市水资源匮乏度不断升高,1995年以来水资源自给率呈下降趋势,与之相对应的水资源依赖度越来越高;(3)农业部门用水量在本地用水量中的比例平均每年为55.1%,虚拟水净输入量在虚拟水净输入总量中的比例平均每年达到89.1%;(4)高耗水型作物产品生产用水比例升高加大了农业用水压力,动物产品生产用水量呈增加趋势,2001—2005年动物产品生产引入的虚拟水占到其虚拟水总量的81.3%。北京市水资源利用呈不可持续状态,通过农业系统内部结构的优化调整,实现农业部门水资源的高效利用是缓解北京市水资源紧缺问题的关键。     

Role of protein conformation and aggregation in pumping water in and out of a cell

Dialysis cassettes containing BSA solutions were used to simulate passive in vivo conditions to assess the effect of protein conformation and aggregation on cell water content. The cassettes were suspended in dextran solutions to provide a range of fixed osmotic stress values simulating blood plasma. The system was placed on a shaker for 24 h to attain equilibrium. Four manipulation methods; pH, cosolute salt concentration, e.g. NaCl, temperature annealing and urea concentration denaturant were varied to produce well-known manipulations of BSA conformation. It was observed that the cell water content varied from +14% to about -13% with changes in protein conformation and aggregation. The findings demonstrate that a change in protein conformation and aggregation, pumps water in and out of a cell to maintain equilibrium % water content matching the protein conformational hydration parameter. This concept supplements existing theories on cell volume regulation.     

宽甸县水中硼的背景浓度及污染现状分析

采集辽宁宽甸县各种水样51个,用ICP—MS分析硼含量。结果表明,宽甸县水中硼含量的背景值与世界水平相当,污染地区地表水和地下水硼含量的平均值分别是背景点的23．1和495．6倍。硼的开采和加工对水体产生了较严重的硼污染。     

工业水足迹评价与应用

大规模的工业生产不但消耗了大量的水资源,同时产生了大量的工业废水,这是造成和加剧全球或区域水资源危机和水环境问题最重要的原因之一。对工业生产过程的水资源综合影响进行科学有效评估是目前资源环境管理领域研究的重要问题之一,是采取有效措施、提升工业生产的水资源利用效率和管理水平的重要前提和基础。以发展和完善工业生产过程的水资源综合影响的评价系统和方法体系为目标,基于水足迹理论,提出了工业水足迹的概念,即用以测量由某一产品、工业企业、行业或区域的工业生产过程引发的水资源利用增量的一个多维指标。以此概念为理论基础,进而首先分析了工业水足迹的内涵,包括直接工业水足迹与间接工业水足迹两部分。另外,区别于全生命周期的水足迹,工业水足迹评价是针对工业生产过程中由于工业原料、辅料、能源和水的输入,以及废水、废物与产品的输出产生的水足迹,其系统边界不包括分销零售、消费使用与废物处理等环节。其次,在确定的系统边界内构建了工业水足迹的核算框架和基础方法体系,即从生产、公共及运输3个方面收集数据、处理并核算。最后,从产品、企业、行业和区域4个层面对工业水足迹的应用及其意义进行了展望。     

Simulations of apo and holo-fatty acid binding protein: structure and dynamics of protein, ligand and internal water.

Two molecular dynamics simulations of 5 ns each have been carried out for rat intestinal fatty acid binding protein, in apo-form and with bound palmitate. The fatty acid and a number of water molecules are encapsulated in a large interior cavity of the barrel-shaped protein. The simulations are compared to experimental data and analyzed in terms of root mean square deviations, atomic B-factors, secondary structure elements, hydrogen bond patterns, and distance constraints derived from nuclear Overhauser experiments. Excellent agreement is found between simulated and experimental solution structures of holo-FABP, but a number of differences are observed for the apo-form. The ligand in holo-FABP shows considerable displacement after about 1.5 ns and displays significant configurational entropy. A novel computational approach has been employed to identify internal water and to capture exchange pathways. Orifices in the portal and gap regions of the protein, discussed in the experimental literature, have been confirmed as major openings for solvent exchange between the internal cavity and bulk water. A third opening on the opposite side of the barrel experiences significant exchange but it does not provide a pathway for further passage to the central cavity. Internal water is characterized in terms of density distributions, interaction energies, mobility, protein contact times, and water molecule coordination. A number of differences are observed between the apo and holo-forms and related to differences in the protein structure. Solvent inside apo-FABP, for example, shows characteristics of a water droplet, while solvent in holo-FABP benefits from interactions with the ligand headgroup and slightly stronger interactions with protein residues.     

Diurnal Pattern of Transpiration,Water Uptake and Water Budget of Succulents with Different CO2 Fixation Pathways

The water fluxes and the CO₂ exchange of three leaf succulents, Othonna opima, Cotyledon orbiculata and Senecio medley-woodii, with different leaf anatomy, growth form and CO₂ fixation pathways (C₃, CAM) were monitored with a gas exchange cuvette which was combined with a potometric system to quantify water uptake. Measurements, which are primarily valid for plants with a sufficient water supply, were made during 6 to 10 consecutive days under constant experimental conditions. Water uptake for 24 h exceeded water loss by transpiration only for a S, medley-woodii plant with 10 expanding but only 7 mature leaves. In this case the gained water evidently is put into leaf expansion. All other plants showed balanced transpiration and water uptake rates. O. opima and C. orbiculata have a similar life form, similar water storage volumes and the same natural habitat but their diurnal water uptake patterns differ significantly. In the C₃ plant O. opima water uptake increased when the transpiration increased or transpiration rates were higher than uptake rates and vice versa. On the contrary the CAM plant C. orbiculata transpired during the dark period at constant or decreasing rates but showed steadily increasing uptake rates. Senecio medley-woodii- and C. orbiculata are CAM plants with similar diurnal water uptake patterns with its maximum in uptake during or towards the end of the CO₂ dark fixation period. Water uptake of C. orbiculata was at its minimum at the end of the light period despite transpiration being maximal. The results were discussed considering the different CO₂ fixation pathways. In the investigated CAM succulents, C. orbiculata and S. medley-woodii, the CAM influenced water uptake throughout the whole day and not only during the CO₂ dark fixation period.     

Aquaporins and biological rhythm

Aquaporins are membrane-intrinsic proteins that facilitate membrane transport of water and small solutes or even gases. Aquaporin genes are found in almost all living organisms. In plants the proteins account for water uptake and transport as well as CO₂ availability for photosynthesis. These processes are subjected to diurnal or circadian regimes. Expression and even function of aquaporins also follows day - night rhythms. Significance of aquaporin function in chronobiology has been provided by recent publications, which are summarised here. Examples of the significance of aquaporins in processes related to chronobiology are given for root water transport and leaf movement in several plant species.     

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。     

Risk assessment of adenoviruses detected in treated drinking water and recreational water

AIMS: Human adenoviruses (HAds) have previously been detected in sewage and polluted river and dam water, as well as treated drinking water. The 51 serotypes of HAds cause a wide range of infections with clinical manifestations associated with the gastrointestinal, respiratory and urinary tracts, and the eyes. Water may play a meaningful role in the transmission of many of these HAd serotypes, specifically the enteric HAds which are transmitted via the faecal-oral route. The presence of these viruses in water used for drinking and recreational purposes is considered to constitute a potential health risk. In this study, the risk of infection by the group of HAds previously detected over a period of 1 year in selected drinking water supplies, as well as river and dam water used for recreational purposes, was assessed. METHODS AND RESULTS: Adenoviruses were previously detected in nine of 204 (4.41%) samples of two drinking water supplies (A and B) treated and disinfected according to international specifications, in four of 51 (7.8%) samples of river water and nine of 51 (17.7%) samples of dam water. Application of these previously published results in an exponential risk assessment model indicated an annual risk of infection of 1.01 x 10(-1) and 1.7 x 10(-1) for drinking water supplies A and B, respectively, assuming a daily consumption of 2 l day(-1). The daily risk of infection constituted by HAds in the river water was calculated as 1.71 x 10(-4), and in the dam water as 3.12 x 10(-5), assuming a consumption of 30 ml of water per day. CONCLUSIONS: The risk of infection exceeded the tolerable risk of one infection per 10 000 consumers per year proposed for drinking water. However, the results for river and dam water used for recreational purposes were within the tolerable risk of one infection per 1000 bathers per day proposed for environmental waters used for recreational purposes. SIGNIFICANCE AND IMPACT OF THE STUDY: The study showed that the risk of HAd infection calculated for the drinking water supplies and the recreational water may overestimate the actual risk of infection, as conservative values were assumed for some of the variables. For a more accurate assessment of the potential risk of infection research should at least include a thorough investigation of the water consumption of individuals in South Africa, and the efficiency of recovery of the glass wool adsorption-elution method.     

启东海域水质营养状况及其与陆域农村水环境质量的关系

根据启东近岸海域2003—2009年7个站点的监测数据,研究了该海域的水质营养状况,并初步分析了与相邻陆域农村水环境质量的关系。结果表明:除平台站点之外,多数站点的COD、DIN、DIP和DO有增加的趋势;仅平台站点在2003年未富营养化,其他6站点都处于富营养状态,在2007年富营养化指数达到最高值,其后逐年显著降低;2003—2009年重污染海域比例达到4.1%,在2007和2008年是污染较为严重的年份;富营养化指数与综合标准指数之间存在显著的正线性相关;相对于城市工业生产生活排放,启东近岸陆域农村水环境质量变化和长江径流对近岸水质营养状况的影响较小。     

Water footprint and economic water productivity assessment of eight dairy cattle farms based on field measurement

Water scarcity prevailing in the drylands is threatening the sustainability of livestock production systems. The water footprint (WF) indicator was proposed as a metric of water use. This study aimed to determine the WF and the economic water productivity (EWP) of 1 kg of fat and protein-corrected milk (FPCM) in eight dairy farms (n = 8; animals = 117 ± 62; area = 198 ± 127; 95% confidence level) in northern Tunisia. Then, to assess the effects of three simulation scenarios targeting the reduction of the WF of milk production (scenario A: using triticale silage to replace, on DM basis, the silage of maize, sorghum or ray-grass; scenario B: reducing by 56% the wastage of water devoted to milking, cooling, cleaning and servicing; scenario C: using concentrate feeds imported from Brazil and Argentina instead of that imported from France). A year-round monitoring of on-farm practices was performed using water-meters and recording equipment installed in key locations in the target dairy farms: (i) water used for feed production, (ii) cow watering, (iii) servicing water, (v) crop and forage production and (iv) economic and production performance were controlled by water source (green and blue). Over the eight farms evaluated, milk production consumed on average 1.36 ± 0.41 m³/kg FPCM, of which 0.93 ± 0.40 m³/kg FPCM was green water and 0.42 ± 0.30 m³/kg FPCM was blue water. However, virtual water of 1 kg FPCM averaged 43% ± 14.3%. Water used for feed production for lactating cows represents approximately 87% ± 6% of the total WF of milk production. However, drinking and servicing water contributed by 3.75% ± 2% and 9% ± 5% to the total WF of milk, respectively. The EWP assessment revealed that the selected dairy farms had a relatively small gross margin per m³ of water averaging US$ 0.05 ± 0.04. The variation in WF of milk was mainly associated with diets’ ingredients, which affected milk productivity and water consumption. Scenario analysis indicated that using feed with less water requirements or importing feeds from countries where its water consumption is low could reduce consumptive water use for milk production by up to 16%. The efficient use of servicing water could reduce blue WF of milk by up to 4%. The implementation of these measures would lead to potential total water savings in the Tunisian dairy sector of 646 million m³ per year (30%).     

Influence of Dielectric Constants and Ligand Binding on Thermostability of Glucoamylase

Thermal stability of glucoamylase [α-1,4: 1,6-glucan-4: 6-glucohydrolase, EC 3.2.1.3] from Rhizopus niveus was investigated in detail mainly at 60.0±0.1°C (pH 4.5) in relation to kinetics both in the presence and in the absence of various ligands. With substrate analogues, such as glucose, lactose and gluconolactone, and with glycerol, thermostability of the enzyme greatly increased, whereas decreased with dioxane, ethanol and glycol. To elucidate such phenomena clearly, several model equations were propounded on the assumption that there were two main factors which would play an essential role in heat stability of the enzyme: binding of ligands and the dielectric constants of solvents. From the model equations, binding constants of the ligands were estimated in order to confirm the validity of the assumption; e.g., the inhibitor constant for glucose (at 59.5°C) corresponding to the reciprocal of binding constant was evaluated to be 0.25 m as was expected.     

Covalently linked immunomagnetic separation/adenosine triphosphate technique (Cov‐IMS/ATP) enables rapid,in‐field detection and quantification of Escherichia coli and Enterococcus spp. in freshwater and marine environments

Aims: Developing a rapid method for detection of faecal pollution is among the critical goals set forth by the Environmental Protection Agency in its revision of water quality criteria. The purpose of this study is to devise and test covalently linked antibody–bead complexes for faecal indicator bacteria (FIB), specifically Escherichia coli or Enterococcus spp., in measuring water quality in freshwater and marine systems. Methods and Results: Covalently linked complexes were 58–89% more robust than antibody–bead complexes used in previous studies. Freshwater and marine water samples analysed using covalently linked immunomagnetic separation/adenosine triphosphate quantification technique (Cov‐IMS/ATP) and culture‐based methods yielded good correlations for E. coli (R = 0·87) and Enterococcus spp. (R = 0·94), with method detection limits below EPA recreational water quality health standards for single standard exceedances (E. coli– 38 cells per 100 ml; Enterococcus spp. – 25 cells per 100 ml). Cov‐IMS/ATP correctly classified 87% of E. coli and 94% of Enterococcus spp. samples based on these water quality standards. Cov‐IMS/ATP was also used as a field method to rapidly distinguish differential loading of E. coli between two stream channels to their confluence. Conclusions: Cov‐IMS/ATP is a robust, in‐field detection method for determining water quality of both fresh and marine water systems as well as differential loading of FIB from two converging channels. Significance and Impact of the Study: To our knowledge, this is the first work to present a viable rapid, in‐field assay for measuring FIB concentrations in marine water environments. Cov‐IMS/ATP is a potential alternative detection method, particularly in areas with limited laboratory support and resources, because of its increased economy and portability.     

条带休闲轮种对坡地水土流失和水分利用效率的影响

为提高宁南旱区坡耕地土壤保水能力、减少水土流失,于2007-2010年在10°～15°坡耕地上,以传统无条带种植模式为对照,研究条带隔年休闲轮种模式对农田土壤水分动态、水土流失特征和水分利用效率的影响.结果表明:经过4年休闲轮种,条带处理比传统无条带种植处理显著增加0 ～200 cm土层土壤含水量4.9％～7.0％;条带轮种比无条带模式有效保蓄雨季休闲期降水,明显改善了作物生育前期的土壤水分状况,条带处理0～200 cm土层土壤含水量比对照显著增加5.4％～8.5％.与对照相比,条带休闲轮种处理地表径流减少0.7 ～3.2 m3·hm-2,泥沙量减少0.2～1.9 t·hm-2,土壤全N损失量减少42.1％ ～73.3％,作物水分利用效率提高6.1％ ～24.9％,降水利用效率提高6.3％ ～15.3％.     

生态环境用水研究现状、问题分析与基本构架探索

生态学与水文学交叉研究是目前国际上前沿研究领域之一,生态环境用水研究则是连接生态过程与水文过程、刻画生态演化与水资源相互关系的核心问题。对生态、环境用水产生与发展的基本过程进行了回顾,并根据对已有成果的综合分析提出了目前研究中存在的5方面主要问题。首先,生态用水尚需理论上的进一步升华,这一点突出体现在生态用水的概念与内涵表述上;其次,在生态用水研究中,缺乏合理的生态保护目标的建立,因而影响到了研究成果的实际应用价值;第三,目前的研究均是针对较大尺度所作的,不能在生态机理与物理机制上揭示生态用水规律,因此,不适于具体问题的深入分析,个别实验在由“点“尺度向生态用水计算的“面“尺度转换时缺乏基础,从而严重影响了研究成果的精度;第四,生态用水机理是生态用水研究中至为关键的工作,以往研究主要依据野外宏观观测资料来探讨,缺乏直接的实验依据;第五,没有涉及生态用水对生态系统稳定性、生态用水满足程度及其波动性对生态系统影响等方面,从而也使得研究成果的科学性受到影响。同时作者认为,中国工程院“中国可持续发展水资源研究报告“中的生态环境用水概念对我国地大物博,地质地貌与气候类型多样的特点给给予了更多的关注,故可以确定为全国性的生态环境用水概念。最后文章认为应当将生态用水与环境用水分别予以考虑,并给出了其新的概念构架。     

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.     

Hydrology and water balance of Lake Peipsi

Lake Peipsi is a large (3558 km²) but shallow (up to 15.3 m deep) tripartite waterbody hydrologically investigated already since the 19th century. Surface discharge by rivers accounts for more than 80% of its water balance. The residental time of water is about two years in the whole lake but several times less in its shallower southern parts receiving the biggest rivers. The annual water regime is characterized by the highest water in spring, the average amplitude of yearly level fluctuations being 1.15 m. There are known long-term hydrological cycles of 80–90, about 22, 9–11, and even fewer years. Several temporary wind-dependent circular currents exist in the subsurface layers. Alternating transitional currents occur in the narrowest part of the lake. Five different periods are distinguishable in the annual thermic cycle. The duration of the stable ice cover is up to five months (December-April) in the shallower parts but a shorter time in the centre of the lake. The maximum surface temperature in July usually reaches 21–22°C in the open regions but considerably higher (up to 27–28°C in some years) on shallows. The unstable summer stratification is often disturbed by waves and currents. Biological summer, with surface temperatures over 10°C, lasts on an average 134 days.     

Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain

AIMS: To evaluate the prevalence of Cryptosporidium and Giardia in surface water supplies from the province of Alava, northern Spain, and to investigate possible associations among the presence of these pathogenic protozoa with microbiological, physicochemical and atmospheric parameters. METHODS AND RESULTS: A total of 284 samples of drinking and recreational water supplies were analysed. Cryptosporidium oocysts were found in 63.5% of river samples, 33.3% of reservoirs samples, 15.4% and 22.6% of raw water samples from conventional and small water treatment facilities (respectively), 30.8% of treated water from small treatment facilities, and 26.8% of tap water from municipalities with chlorination treatment only. Giardia cysts were found in 92.3% of river samples, 55.5% of reservoirs samples, 26.9% and 45.2% of raw water samples from conventional and small water treatment facilities (respectively), 19.2% of treated water from small treatment facilities, and 26.8% of tap water from municipalities with chlorination treatment only. The presence of Cryptosporidium and Giardia had significant Pearson's correlation coefficients (P < 0.01) with the turbidity levels of the samples, and a number of significant associations were also found with the count levels for total coliforms and Escherichia coli. The samples were positive for Cryptosporidium significantly (P < 0.05) more frequently during the autumn season than during the spring and winter seasons. No significant differences were found in the seasonal pattern of Giardia. A moderate association (r = 0.52) was found between rainfall and the presence of Cryptosporidium oocysts. CONCLUSIONS: Cryptosporidium and Giardia are consistently found at elevated concentrations in surface waters for human consumption from the province of Alava, northern Spain. SIGNIFICANCE AND IMPACT OF THE STUDY: Water treatments based on rapid filtration process and/or chlorination only are often unsatisfactory to provide safe drinking water, a situation that represents an important public health problem for the affected population because of the risk of waterborne outbreaks.     

Effects of microtopography and water table on Sphagnum palustre L. in subtropical high mountains and implications for peatland restoration

Introduction. Human disturbance has recently led to increasingly serious destruction of Sphagnum L. wetlands in subtropical high mountains, resulting in an urgent need for wetland restoration.

Methods. Through a field experiment conducted in western Hubei Province, China, the effects of four different microtopographic types [concave surface, convex surface, concave and convex surface (CC surface), and flat surface] and water table depth (0 to ?30?cm) on three growth indicators (number of capitula, coverage and biomass) of Sphagnum palustre L. were examined. The objective was to identify the optimal hydrological conditions for S. palustre growth and thus facilitate its rapid recolonisation and restoration of these wetlands.

Key results. The results showed that different microtopographic conditions significantly influenced S. palustre growth. Among them, S. palustre in the CC surface showed the worst growth, while no significant differences existed among the other three microtopographic types. Additionally, as the water table increased, the growth of S. palustre increased, but long-term flooding impeded growth. The water table affected S. palustre growth via effects on its tissue water content.

Conclusions. Microtopographic reshaping was not essential for the success of S. palustre recolonisation, and microtopography that maintained the water table to within ?10?cm of the surface without flooding were best, independent of the microtopographic types. In addition, the growth patterns of S. palustre changed with changes in the environment, which may be related to its long-term adaptation to conditions of a lower water table.