跨流域调水背景下汉江流域洋县段的鱼类多样性及资源现状

汉江是南水北调中线工程和引汉济渭等跨流域调水工程重要的水源区, 了解其鱼类多样性的现状及变化对于水生态保护尤为重要。作者于2016-2017年间对汉江洋县段干流与6条主要支流的鱼类多样性组成进行了两次调查, 以Margalef丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数和Jaccard相似性系数对洋县境内7条河流进行评估, 同时通过相对重要性指数(index of relative importance,IRI)判定优势种, 利用鱼类丰度生物量(abundance biomass comparison, ABC)曲线分析鱼类受干扰情况。结合历史记录, 调查区域内共分布有土著鱼类76种, 隶属于6目14科57属, 以鲤形目鲤科和鲇形目鲿科鱼类为主, 分别占土著鱼类总数的57.89%和11.84%; 珍稀濒危鱼类共计5种, 包括3种国家级保护水生野生动物。鱼类多样性分析结果显示汉江干流的丰富度指数和多样性指数显著高于6条支流。7条河流的IRI指数显示优势种为宽鳍鱲(Zacco platypus)。ABC曲线显示目前调查区域内鱼类小型化现象明显、鱼类受到较严重干扰。水利水电工程建设对于调查区域鱼类多样性影响最大, 干流大型水库(大坝)通过改变原有流水生境、阻断河流纵向连通性、淹没重要鱼类产卵场等对鱼类多样性和群落组成产生不利影响; 支流引水式的中小型电站造成下游河段减、脱水而使河道发生断流以及生境破碎化, 从而威胁土著鱼类的生存。在跨流域调水过程中, 应重视不同水系鱼类引入的潜在生态风险。对引汉济渭工程的水源区鱼类多样性现状的调查, 有助于未来跨流域调水过程中鱼类变化的动态监测和外来物种的预警。     

南水北调对海河流域水生态环境影响分析

提出可定量分析研究流域水循环变化对水生态环境影响的关联分析方法 ,并对海河流域现状进行了关联分析和和评价。分析研究表明人类对水资源的过度开发利用已改变了海河流域的天然水循环并导致水生态环境全面退化。进一步对未来无南水北调和有南水北调的情况进行定量模拟计算 ,结果表明在无南水北调的情况下 ,未来海河流域将处于无法兼顾发展经济和保护生态环境的困境 ;在实施南水北调的情况下 ,水资源可支撑海河流域经济发展并影响和改善整个流域的水循环状态 ,从整体上遏制海河流域水生态环境恶化的趋势 ,但入海水量仍无法改善     

Impacts of Nutrient Loading on Mercury Fractionation and Mobility in an Estuarine Wetland in Nansi Lake,China

Total mercury is closely related to nutrient status in ecosystems. However, studies specifying the effects of various nutrient forms on the mobility of mercury are rare. In this study, three fractions of mercury (mobile, semi-mobile, and non-mobile) were examined in the soil of an estuarine wetland with excessive nutrient inputs in northern China. The wetland is located in the east route of China's South-to-North Water Transfer Project. Correlations between the three fractions of mercury and four nutrient parameters were analyzed. Results showed that toxic mobile and semi-mobile mercury comprised a great portion of total soil mercury in the studied wetland. Among the four nutrient parameters, ammonium nitrogen showed a significant negative correlation with mobile toxic mercury and was the principal nutrient component that influenced the mobility and toxicity of mercury. Nitrate nitrogen showed a positive correlation with mobile toxic mercury. Moreover, carbon/nitrogen ratio and soil acid were positively correlated with mercury mobility. Given that lower nitrogen loading is required in the watershed to ensure the water quality during the water transfer project, our study suggested that changes in nitrogen inputs might promote the mobility and bioavailability of mercury in the watershed. Thus, more attention should be provided to the potential hazard of mercury in the food web during the water transfer.     

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.     

基于基尼系数和锡尔指数的中国水足迹强度时空差异变化格局

水足迹可以衡量人类对水资源的真实占有量,而水足迹强度则表征了人类对水资源的利用效率水平。在计算出1997-2007年中国各地区水足迹的基础上,借助于基尼系数和锡尔指数计算方法,探索分析中国近11a水足迹强度发展的空间格局变化规律。结果表明:中国水足迹强度整体呈下降趋势,水资源利用效率有所提高,但是区域发展不平衡;水足迹强度区域总差异经历了"先增大后缩小"的过程,中东西三大地带空间发展呈先极化后趋同的态势,南北区差异总体有所缩小;对水足迹强度区域内部差异贡献份额南方大于北方、东部大于中西部;促使空间差异格局变化的主要因素为区域发展策略、经济发展水平和市场发育程度等;另外,发现中国水污染足迹强度区域差异极化现象非常严重,说明随经济的发展部分地区水污染问题很严峻。最后针对发现的问题提出了协调我国经济发展与水资源利用的相应建议。     

南水北调与生态平衡

水是人类赖以生存繁衍的重要资源。我国人口逐年增长,而淡水资源数量有限。多变的自然降水及频繁的旱涝灾害,一直决定着我国农业收成乃至整个国民经济的盛衰。     

中国水生态足迹广度、深度评价及空间格局

运用生态足迹方法对水资源进行流量资本和存量资本区分,测算分析了中国31个省市1997—2014年的水生态足迹广度与深度。结果显示:(1)中国的水生态足迹广度受年际水资源量丰枯影响,总体呈波动趋势;各省市的水生态足迹广度存在着明显差异,南方地区水生态足迹广度普遍大于北方地区;(2)研究期内,中国的水生态足迹深度只有1998年为1,其余年份的水资源流量资本已不能满足人类生产生活的需求,需要消耗水资源存量资本;各省市之间水生态足迹深度相差较大,整体上北方高南方低,其中14个省份18年的平均水生态足迹深度为1,平均水生态足迹深度最高的地区是宁夏的308.12;(3)运用空间自相关方法对31个省市的水生态足迹广度和深度进行分析得出,中国省际水生态足迹广度与深度均存在明显的空间集聚现象。水生态足迹广度H-H集聚地区主要集中在中国南方地区,水生态足迹深度H-H集聚地区主要集中在中国北方地区。通过对全国水生态足迹广度与深度的测度分析为水生态足迹分析提供新的研究方法,同时也为区域水资源可持续利用提供理论依据。     

Experimental study of vibrio parahaemolyticus (biotype 2) transfer from water and sediments to benthic marine food chain organisms]

Transfer of Vibrio parahaemolyticus (biotype 2) from sediments to water and from water to benthic marine organisms was studied experimentally using a streptomycin-resistant strain. Transmission by trophic pathways was also studied using reconstituted marine food chains (Mytilus edulis, Nereis diversicolor, Carcinus maenas, Scorpaena porcus, Mus musculus). Water colonization by sediments could be observed only at temperatures above 16 degrees C. Sediments could well constitute a disseminating reservoir for these germs, their cycle in water being dependent of the cycle followed in the sediments. Contamination of animal organisms is essentially effected by a direct mean, either water or sediments; transfer by trophic pathways being negligible. Infection of land consumers (mice) is linked quantitatively to the nature of the last marine organism of the food chain since bacteria can flourish in the digestive tract of certain animals (Carcinus maenas).     

汉江上游金水河流域森林植被对水环境的影响

以汉江上游金水河流域为研究区域,分析了流域森林植被对水环境的影响。利用年降水量、林冠截留率和不同森林类型面积的数据,计算了金水河流域森林生态系统的水源涵养量,分析了流域森林植被对水量的影响;采用监测的方法,分别对金水河流域阔叶林森林生态系统的大气降水、枯落物层、土壤层和出口河水的水质进行了比较分析,探讨流域森林植被对水质的影响。结果表明,(1)金水河流域森林生态系统的水源年涵养总量为466.79×106m3,(2)流域阔叶林森林生态系统能够调节pH值,缓解大气降水的酸性环境;降低了大气降水中TDS、CODMn、HCO3、SO4、Cl、NO3、NH4-N、NO3-N、PO4-P、TDP、As、Ba、Cr、Na、Pb、Fe、K、Mn、V和Zn的含量,净化了水质。(3)根据各贮水层的水质分析,推断了河水中各物质的不同来源。研究为南水北调中线工程水源地的管理和建设提供了参考。     

基于生态系统净化与人为调控耦合作用的水环境承载力评估

针对目前水环境承载力相关研究中未突显生态系统净化作用和人为调控作用的问题,从生态系统污染净化功能和人为调控污染削减功能两个角度,提出基于生态系统净化-人为调控耦合作用的水环境承载力概念,并构建流域环境承载力评估模型。以滇池流域为例,计算了2015年滇池流域水环境承载力。研究结果表明:滇池流域2015年水环境承载力综合指数为1.16,处于超载状态;流域环境承载力分布呈现北高南低,北部限制因子化学需氧量,南部为总磷;调水工程调入水量出境携带污染物约为流域水环境承载力的16%,对流域水环境改善十分重要;人为调控污染削减能力在流域水环境承载力中所占比例已超过50%,成为不可忽视的一部分。     

1994年丹江口库区调查发现的石制品研究

本文报道了1994年在南水北调中线工程丹江口库区多处地点采集的624件石制品。石制品类型有石核、石片和石器;石器占44%以上, 类型丰富, 包括手斧、手镐、薄刃斧、砍砸器、石球、尖状器、刮削器和石锤; 石器素材主要为砾石, 大多数个体粗大。这一石器组合与中国南方的砾石石器工业有较多的相似之处; 手斧工具的出现表明,这些石制品在探讨东、西方的旧石器文化交流方面也是非常重要的材料。     

基于投入产出分析的北京市虚拟水核算

城市化进程的加快与工农业的迅速发展使城市水消耗量日趋增加。水资源短缺不仅会造成居民生活质量下降,还会制约社会经济的可持续发展。从贸易和消费的角度核算虚拟水可为研究城市水资源管理提供新的视角。通过投入产出分析了构建了城市系统虚拟水核算模型,利用虚拟水直接和完全用水系数、虚拟水消费量等指标分析城市虚拟水消耗和虚拟水进出口特征。以北京市为例,利用2012年北京市投入产出表和部门的水资源消耗数据核算不同部门的用水系数、最终消费虚拟水量、虚拟水进出口贸易量及部门间虚拟水流转量。结果表明:北京市为虚拟水净进口城市,净进口虚拟水量6.77×10~9m~3,相当于北京市虚拟水用水总量(8.25×10~9m~3)的82%,农业和制造业为主要虚拟水进口部门;北京市虚拟水出口结构存在不合理之处,经济投入产出表中各部门出口总额占最终消费的79.9%,但出口产品消耗的虚拟水占了最终消费隐含虚拟水的85.04%,其中农产品消耗6.7%虚拟水但经济收益仅占1%,说明北京市出口以较大的虚拟水消耗量换取了较少的经济收益,需要减少虚拟水含量较大但经济价值不高的产品出口(如农产品);识别出的主要虚拟水流出-流入关系部门包括农业-制造业,农业-服务业和制造业-建筑业等部门的关联关系,可成为减少间接水消耗的关键路径。     

Eichhornia crassipes (Mart) solms: From water parasite to potential medicinal remedy

Water hyacinth, Eichhornia crassipes (Mart) Solms, originating in the amazonian basin, is a warm water aquatic plant. Water hyacinth is considered one of the most productive plants on earth and, accordingly, is considered one of the top ten world''s worst weeds. Water hyacinth spread to other tropical and subtropical regions by humans. It invaded about 62 countries in Africa, Asia and North America, and propagated extremely serious ecological, economical and social problems in the region between 40 degrees north and 45 degrees south. The dense weed of water hyacinth forms dense monocultures that can threaten local native species diversity and change the physical and chemical aquatic environment, thus altering ecosystem structure and function by disrupting food chains and nutrient cycling. We have separated and identified nine active fractions from water hyacinth and showed their promising therapeutic activities. Several compounds (alkaloid, phthalate derivatives, propanoid and phenyl derivatives) were identified in the extract of water hyacinth.Key words: water hyacinth, antimicrobial, anticancer, active compounds     

南水北调中线工程对海河流域鱼类入侵风险分析

海河流域是南水北调中线工程的受水区之一, 为评估中线工程引发海河流域鱼类入侵的风险, 本研究统计了南水北调引水区和受水区海河流域鱼类物种多样性差异, 采用水生生物入侵能力筛查系统(aquatic species invasiveness screening kit, AS-ISK)和外来鱼类入侵风险评估体系筛选引水区有入侵风险的鱼类物种, 并用MaxEnt模型预测有入侵风险的鱼类物种在海河流域的潜在适生区。结果表明, 丁鱥(Tinca tinca)、陈氏新银鱼(Neosalanx tangkahkeii)和大口鲇(Silurus meridionalis)是具有高入侵风险的鱼类, 另有3种鱼类具有中入侵风险, 均需重点监控; 而具入侵风险鱼类的适生区预测结果表明, 海河流域南部的徒骇马颊河水系、海河水系的漳卫南运河以及环渤海地区的河流是极易发生鱼类入侵的水域。因此在海河流域高入侵风险水域应开展持续性的水生生物监测, 针对具有高入侵风险的鱼类应进行早期筛查, 此外在水资源利用和分配上应加强管理, 从源头上杜绝鱼类入侵的发生, 还应尽快开展针对东线工程的鱼类资源调查和入侵风险评估工作。     

The Cultural Relics Distribution Characteristics Along the Canal Line and Appraisal of its Influence by the Middle Route Project for Water Transferring from South to North China

Assessments of the impacts of environmental hazards on ecological systems and human health have become a subject of ever-increasing importance. In this work, we extend current ecological hazard evaluation to the problem of protecting cultural relics from hazards attributable to the presence of a large-scale canal system being planned in China. The development and utilization of water resources must be closely combined with the preservation of cultural relics. The Middle Route Project for Water Transfer from South to North China (MRWT) is a current example. In this paper, the engineering background of this project is briefly introduced. The distribution of cultural relics related to it is also summarized in terms of different geographical divisions. An influence index E = f(L, δh, k, I, v, s) is introduced to measure the comprehensive effect of the canal on cultural relics. Because this function is really established at the preconstruction stage, it is treated by use of fuzzy mathematics. Each cultural relic has its own E value. Cultural relics with E values greater than 0.75 should be paid high attention, while those with E less than 0.5 may generally be ignored. What must be preserved through use of engineering measures are cultural relics with E values greater than 0.9. As to those cultural relics with E ranging between 0.5 and 0.75, whether they should be preserved with engineering controls depends upon practical circumstances specific to each relic.     

Food web structure and ecosystem properties of the largest impounded lake along the eastern route of China's South-to-North Water Diversion Project

Hongze Lake (HZL) is the largest impounded lake along the eastern route of China's South-to-North Water Diversion Project. However, there is surprisingly little ecological understanding on this important ecosystem, especially under the potential water diversion threats. Here, a mass-balance model was constructed to characterize trophic structure and ecosystem properties of HZL. The model outputs indicated that small sized fishes have dominated the food web, and fishery resources were suffered from high pressures of overfishing. Mandarin fish, Northern snakehead, Other piscivores and Large culters occupied the top trophic niche, while macrophytes, phytoplankton and detritus consisted of the main energy sources. HZL food web was fairly based on two main food chains: primary production (49.9%) and detritus pool (50.1%), but transfer efficiencies in both chains were relatively low as 6.37% and 6.49%, respectively. Predator-prey interactions, trophic cascading effects and competition of different components were also exhibited in the mixed trophic impacts map. Results from the network analysis suggested that the HZL ecosystem was a relatively mature ecosystem since the total primary production to respiration (TPP/TR) and to biomass (TPP/TB) were 1.138 and 6.922, and the Finn Cycling Index was 6.77%. Nevertheless, the relatively low values of Connectance Index (0.195) and System Omnivory Index (0.089), together with Finn's Mean path Length (2.849) also indicated that the food web structure was vulnerable, characterized by linear, rather than web-like features. Our results suggested that the HZL ecosystem would be potentially affected by the future inter-basin water diversion, and thus ecosystem-based strategies were also presented accordingly.     

调水工程输水管道建设对地表植被格局的影响——以南水北调河北省易县段为例

随着生态环境不断恶化,水资源紧缺已成为全球性的环境问题,跨流域调水工程是保障区域水资源合理配置,保证区域生态安全、区域经济和社会可持续发展的重要措施之一。但是调水工程会不可避免的对施工建设区的生态系统带来人为干扰,对施工建设的地表植被格局产生影响。以南水北调中线一期工程河北省易县段大型输水管道工程建设区作为研究对象,选取了施工建设前(2000年)、施工建设期(2008年)和施工建设后(2013年)3个不同时间段的遥感影像数据,通过解译施工建设区地表植被类型的变化,采用象元二分法提取植被覆盖度,比较不同时期植被覆盖格局和土地利用格局的动态变化,探讨了输水管道建设对周边生态系统影响的范围和特点。研究表明:施工建设前、中、后期管道沿线土地利用类型有较大变化;随着输水管道的建设,人为干扰逐渐增强,施工作业带成为该区域的主要建设用地,并造成了弃置用地和土地裸露,减少了耕地和草地的面积。同时,输水管道建设施工对研究区内植被覆盖度产生了明显的影响,总体上呈现出先减少后增加的趋势。管道建设期对沿线植被、土壤生态系统影响明显,其范围主要在管道施工作业带中心两侧各100 m;在这个区域以外,影响强度大幅降低。     

Effects of Soil Properties and Flooding on the Mobility and Transformation of Mercury in a Temperate Riparian Wetland

Three fractions of mercury (mobile, semi-mobile, and non-mobile mercury) were detected in the soil of an estuarine wetland in Nansi Lake, which is on the east route of China's South-to-North Water Transfer Project. The correlations between these mercury fractions and soil properties were examined under different levels of toxicity. Furthermore, the effects of two flooding conditions (permanent flooding and seasonal flooding) on mercury mobility were analyzed. Results showed that soil pH was negatively correlated with mobile mercury, whereas semi-mobile mercury was positively correlated with total aluminum, iron, and manganese. Moreover, free alumina was positively correlated with all three fractions of mercury. Our study suggests that high contents of soil acid and free alumina might promote wetlands as “sinks” for mercury sequestration, along with low concentrations of organic matter and manganese. In addition, seasonally flooded wetland might limit the production of toxic mobile mercury more than permanently flooded wetland. Large areas of seasonally flooded wetlands in the watershed are permanently flooded by the water transfer project, which elevates the water level during the dry season. As a result, the potential toxicity of mercury may increase in the watershed during water transfer, which should gain more attention.     

Spatial variation in density, mean size and physiological condition of the holarctic amphipod Diporeia spp. in Lake Michigan

• 1 We examined spatial patterns in population characteristics (density, biomass, mean body length) and physiological condition (lipid content, length‐weight) of the amphipod Diporeia spp. in Lake Michigan by collecting samples at up to 85 sites in late summer 1994 and 1995. Variables were examined relative to water depth and three lake regions: south, central and north. Most major river systems are found in the south, and this region is more nutrient‐enriched compared to the north.
• 2 Over all sites, mean density was 5240^‐2, biomass was 4.1g dry wt m^‐2, and mean body length was 5 mm. While maximum densities were related to depth, with a peak at 30–70 m, greatest densities occurred on the west side of the lake, and low densities were found in the south‐east, north‐east and lower Green Bay. High densities in the west probably resulted from upwelling, and reduced densities in the south‐east may reflect food competition with Dreissena polymorpha (zebra mussel).
• 3 Lipid content, weight per unit length, and mean length declined with increased water depth, but depth‐related trends were most evident in the south. Overall, mean lipid content and weight per unit length were significantly lower in the south (16.6% dry wt, 0.59 mg at 5 mm body length) compared to the north (23.7% dry wt, 0.78 mg at 5 mm body length). These regional differences may have resulted from greater diatom availability in the north and competition from D. polymorpha in the south. Triacylglycerols and phospholipids were the dominant lipid classes in all three regions. Although the mean proportion of triacylglycerols, the energy‐storage lipid, was lower in the south than in the north, regional differences in proportions of lipid classes were not significant.
• 4 Mean lipid content and weight per unit length of Diporeia in the south were lower than values found in the late 1980s prior to the establishment of Dreissena. Mean lipid content of mature individuals is now at levels considered a minimum for successful reproduction.

     

丹江口库区湿地水生维管束植物的区系研究

丹江口水库是国家南水北调中线工程的水源地,位于鄂豫两省交界处。其库区湿地是我国现今保存最为完整的湿地之一,已被列入《中国重要湿地名录》。库区湿地水生维管束植物物种丰富,共计有30科56属90种。该区系的地理成分比较复杂,以世界分布、泛热带分布和北温带分布类型为主,表现出明显的亚热带特征。在与国内其它9处湿地进行水生维管束植物区系比较后表明：各湿地与丹江口库区湿地相似系数的大小与其所处的地理位置和气候条件关系密切。