窟野河流域不同水体同位素及水化学特征分析

通过野外调查取样和室内测试分析,应用水化学和同位素技术,分析了窟野河流域不同水体的水化学和氢氧同位素特征,探讨了不同水体的关系。结果表明:(1)河水的水化学类型由上游的Na~+-Ca~(2+)-HCO_3~--SO_4~(2-)演变为下游的Na~+-Ca~(2+)-SO_4~(2-)-HCO_3~-。上游矿井水水化学类型与上游河水一致;上游矿区生活用水距离河道1 000m以内,井深180m的水样点,水化学类型与河水一致;距离河道1 000m,井深180m的水样点,水化学类型与河水有一定的差距。下游灌溉用水水化学类型为Ca~(2+)-Na~+-SO_4~(2-)-HCO_3~-,与河水一致。(2)流域大气降水线斜率和截距都小于全球大气降水线和中国大气降水线,表现出氢氧同位素大陆效应的影响。从上游向下游,河水的氢氧同位素组成有逐渐富集的趋势。上游乌兰木伦河矿井水氢氧同位素与河水氢氧同位素组成相近,说明河水与矿井水水力联系密切。生活用水由于取样井深的不同和距离河道远近的不同导致各样点氢氧同位素含量具有一定的差距。下游灌溉用水的氢氧同位素组成与河水相似。     

区域尺度河道对达里亚博依绿洲植被群落的影响

研究干旱区绿洲天然荒漠植被的分布规律和制约因素,对荒漠地区的植物保护和生态恢复提供一定的理论依据,而干旱区水资源控制着荒漠河岸植被的分布格局,河流对植被的发生、发展和演变起到决定性作用。在于田县克里雅河中下游河道基础上,应用经典统计学和相关分析法分析了达里亚博依绿洲植被群落特征同距河道远近和土壤水分数据间的相关性,探讨了区域尺度基于河流因素的植被群落特征。结果表明:距河道从近到远依次为芦苇（Phragmites australis）群落（0～200 m）、柽柳（Tamarix chinensi）群落（200～800 m）和胡杨（Populus euphratica Oliv）群落（800～1 700 m）;植物群落距河道距离与植被盖度和土壤水分呈负相关;同种植被群落植被盖度、土壤含水率与河道具有同样的相关性,而且离河道越远植被长势越差。     

传统民间竹制折扇设计思想探微

折扇是传统扇子的改良型产品,既具有消暑降温、避阳取风的实用功能,也具有很高的文化价值和艺术价值,是传统民间器具中重要的一员。文中介绍了折扇的发展历史、制作工艺,从设计的角度分析了折扇的设计思想,即简洁实用的设计功能、折叠便携的设计理念和雅俗共赏的设计文化。     

Experimental evidence for species‐specific response to turbidity in imperilled fishes

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Distribution and environmental requirements of stream habitat with Ranunculion fluitantis and Callitricho‐Batrachion vegetation in lower Belgium (Flanders)

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拦河大坝对河流有色溶解有机质赋存特征的影响初探

运用紫外-可见吸收光谱和三维荧光光谱技术,分析了长江三峡大坝上下游河水中有色溶解有机质(CDOM)的含量水平和荧光组分构成及其空间变化。结果表明,自三峡水库支流香溪河河口(回水区)向下游至三峡水库主库区,CDOM的紫外吸收系数(a355从1.30 m-1增至5.21 m-1)和类酪氨酸组分荧光强度及其在荧光组分中所占比例(从25%升至62%)均呈上升趋势,至三峡大坝附近达到全段峰值,而类腐殖质荧光强度及其在荧光组分中所占比例逐步下降;过坝后,CDOM吸收系数在黄陵庙处急剧降至全干流检测段最低(a355=0.95 m-1),但类腐殖质在荧光组分中所占比例达到全段最高(76%);再往下游至葛洲坝库区南津关处,CDOM吸收系数(a355=6.83 m-1)又回升至全段最高,其中类酪氨酸为绝对优势组分。水体类酪氨酸组分的增加主要源自水库浮游生物新生产活动以及微生物转化作用的增强;而CDOM的减少是因为颗粒物的吸附作用。拦河大坝形成的湖泊效应和下泄流过程将对河流有色溶解有机质的赋存特征有显著影响。     

黄河下游河流健康评估指标体系研究

黄河下游是一条高度人工化的河流,是黄河"水少沙多"等诸多问题影响最为剧烈的区域。维持黄河下游健康,不能盲目追求河流自然功能的恢复和扩大。黄河下游河流健康评估指标体系的构建应充分考虑水沙、河道、生态等实际特点,紧密结合黄河下游的经济社会背景,针对黄河下游所承担的功能定位,强调评估指标体系的可操作性、指导性、动态性与适应性,协调黄河下游河流自然生态功能与社会服务功能的均衡发挥。黄河下游河流健康评估指标体系在遵循全国河湖健康评估指标体系的基础上,进行了调整优化。在水文水资源准则层中,取消了"流量变异程度"指标;在物理结构准则层中,增加了"主槽过流能力"指标;在水质状况准则层中,将"DO水质状况"和"耗氧有机物状况"综合为"水质状况"指标;在生物及栖息地准则层中,取消了"底栖动物完整性指数"指标,将"鱼类损失指数"调整为"珍稀濒危及特有土著鱼类生物损失指数",增加了"天然湿地保留率"指标和"珍稀濒危及特有土著鱼类栖息地状况"指标;在社会服务功能准则层中增加了"饮用水源地安全状况"、"景观舒适度"和"公众满意度"等指标。河流生态状况准则层和社会服务功能准则层不进行加权计算,河流健康状况由河流生态状况准则层和社会服务功能准则层分别进行表征。     

江河源头不同程度退化小嵩草高寒草甸草场的封育效果

通过对位于江河源头达日县的不同退化程度小嵩草Kobrecia parva高寒草甸3年的封育研究,结果表明:围栏封育对不同退化程度小嵩草高寒苹甸草场的总盖度及不同经济类群植物的益度、总地上生物量、不同经济类群植物的地上生物量及其组成、退化群落对未退化群落(原生植被)的相似性系数均有显著的影响。经过3年的封育后,草地植被总盖度、总地上生物量、禾本科和莎草科植物的盖度和地上生物量、群落的相似性系数均有不同程度的增加。轻度退化草地封育2-3午后,草地的优良牧草及可食杂类草不论是盖度还是地上生物量均高且占绝对优势,草地即可得到恢复;中度退化草地要靠封育恢复需要的时间可能会更长一些;重度和极度(黑土滩)退化草地,必须通过建植人工草地、结合补播、施肥、毒杂草防除等其它措施改良,以治本的工程措施为主。     

Is the decline of freshwater mussel populations in a regulated coastal river in south‐eastern Australia linked with human modification of habitat?

• 1. The Hawkesbury‐Nepean River provides potable water for 5 million people living in the Sydney basin, and water for agricultural and horticultural production that meets most of Sydney's daily needs for fresh food. Anecdotal evidence indicated that numbers of freshwater mussels have seriously declined in much of the river over recent decades.
• 2. A field survey revealed the presence of populations of three species of mussels, Hyridella depressa, Hyridella australis and Velesunio ambiguus in the river. Higher density mussel populations were most common in catchment areas with little human modification to the channel bed or adjacent vegetation communities.
• 3. Levels of disturbance of riparian vegetation and, to a lesser degree, land use, were identified as being strongly associated with the absence of mussels from some reaches.
• 4. Catchment geomorphology was also shown to be relevant to the abundance, population structure and suite of mussel species present in different geomorphic reaches of the river. Absence of mussels was noted from areas where they had been recorded in previous studies. These results demonstrate that mussel species are under threat in the catchment.
• 5. As filter feeders with the ability to remove excess nutrients and bioaccumulate toxic substances, freshwater mussels play an important role in natural remediation processes in freshwater systems.
• 6. The decline in mussel populations in the Hawkesbury‐Nepean River highlights concerns for the overall health of the river system, and supports the need to identify the subsidiary impacts of physical habitat modification in developing both riverine and riparian management strategies.

Copyright © 2006 John Wiley & Sons, Ltd.     

Physical habitat,eco‐hydraulics and river design: a review and re‐evaluation of some popular concepts and methods

• 1. Improved linkage between physical characteristics of rivers and biological performance or potential is a recurrent theme in contemporary river survey, management and design. This paper examines the degree to which flow biotopes and functional habitats may be differentiated with respect to physical habitat delimiters, i.e. flow depth, velocity and Froude number.
• 2. Re‐examination of published data demonstrates only very broad associations between biotopes, functional habitats and ‘low’, ‘medium’ and ‘high’ bands in the chosen physical habitat delimiter. The associations are also not consistent between different delimiters.
• 3. Re‐analysis is complicated by considerations of research design and methodology. Further studies are required with greater control on the circumstances of observation (particularly flow stage and seasonality), which explicitly control for variance within and between different river cases, and which adopt more consistent terminology.
• 4. Field data for a single river reach at low and high flows indicate that use of the Froude number, in particular, requires careful interpretation. Very different velocity and depth combinations can exhibit similar Froude numbers. This may obscure important contrasts, such as those between channel margin and channel centreline environments.
• 5. Field data also reveal that the flow characteristics of even basic (riffle or pool) units of channel morphology exhibit strong stage‐dependence. There are also significant variations when channel margins are isolated from the definitions of the bedforms or analysis of the data. Current practice which seeks to simplify field survey to channel cross‐section transects is therefore likely to be misleading.
• 6. Given these difficulties, attempts to link biotopes with ecological response appear premature. Further research might, however, be directed to identifying possible associations between combinations of flow types and bedforms or functional habitats. In this sense, the biotope concept may be more profitably employed as one of several surrogate measures for potential biodiversity.

Copyright © 2006 John Wiley & Sons, Ltd.