新型生态植被毯边坡防护技术水土保持效应研究

新型生态植被毯边坡防护效果良好,目前常用的植被毯种类有椰丝型、麦秸型以及椰丝麦秸混合型。为优选出性价比最高的植被毯材料,对这3种植被毯上建植植被的植被覆盖度、有效根密度、地表径流量、土壤侵蚀量和土壤抗蚀性能进行了对比分析。结果表明,与在自然坡面上建植植被相比,植被毯护坡均可以增加土壤的覆盖度,减少降水的径流量与土壤侵蚀量。结合植被毯的产品质量指标,椰丝麦秸混合型植被毯性价比较高,可以作为普遍推广的植被毯品种。研究成果可为植被毯的施工及推广应用提供一定科学依据。     

黄河干流水生态系统结构特征沿程变化及其健康评价

根据2008年黄河干流刘家峡以下河段水生态调查资料,分析了黄河干流水生态系统理化性状和生物群落结构的沿程变化。参照20世纪50和80年代水生态调查资料,对比了黄河干流水生态系统几十年来的变化情况,并分析了变化的原因。通过建立黄河水生态系统健康评价指标,对黄河干流各河段的水生态系统健康状况进行了评价,揭示了黄河水生态系统的现实状况。研究结果表明:由于自然和人类活动影响的差异,黄河干流水生态系统结构特征沿程分布差异比较大;2008年黄河干流水生态状况与20世纪50、80年代相比,除底栖动物外,其它生物种类和数量均下降明显;黄河水生态系统健康状况不容乐观,干流大部分河段生态系统的结构和功能发生了较大的变化,部分生态功能丧失。     

Identifying the natural flow regime and the relationship with riparian vegetation for two contrasting western Australian rivers

The natural flow regime and the relationship between flows and riparian vegetation are described for sites on both the Blackwood River in south‐western Australia and the Ord River in north‐western Australia. Analysis of long‐term flow data showed the historic mean monthly river discharge for the Blackwood River is strongly seasonal and highly predictable with generally low variability each month. The Ord River showed a strong seasonality of flows with about 92% of the (total) yearly flow occurring between December and March. Flow variability was very high (e.g. coefficient of variation >100% for all months) but highly predictable, with this mostly attributed to low but constant dry‐season flows. Water depth, duration of flood events and the number of flood events per year show a significant correlation with aspects of the riparian vegetation within experimental vegetation plots. Results highlight the strong relationship between floristics, life form structure and population dynamics with stream hydrology. On the Blackwood River, species richness and cover of shrubs reduced with increased duration and frequency of flooding, while cover of exotic species and annual herbs increased with increased flooding. Germination of tree seedlings was not influenced by flood regime but size class of tree species increased with flooding frequency. On the Ord River, species richness was not influenced by flooding regime. However, cover of perennial grasses increased with flooding frequency whilst cover of shrubs decreased. There was no relationship between flooding and seedling establishment whilst tree size class decreased with increased flooding. The methods described here can be used to compare the response of different components of the riparian vegetation to different fluvial regimes (e.g. because of impoundment and abstraction). This technique can be expanded for the management of riparian zones and planning rehabilitation programmes. It may also be useful for improving the ecological knowledge base for setting environmental flows in regulated systems. Copyright © 2001 John Wiley & Sons, Ltd.     

人工湿地中水生植物的作用和选择

综述国内外有关人工湿地水生植物在污水净化过程中的作用及其选择的研究成果,提出了人工湿地系统水生植物有待进一步研究的问题。人工湿地水生植物的主要作用为:吸收利用和吸附富集污染物质、传输氧到湿地系统、为微生物提供栖息地、维持系统的稳定、积累有机物质。人工湿地系统要选择栽种耐污能力强、去污效果好、适合当地环境、根系发达、有一定经济价值的水生植物。     

淮河流域水生态服务功能类型研究

明确区域水生态特征与水生态服务功能类型是水生态保护工作的基础和前提。在分析淮河流域水生态问题的基础上,结合流域内生态服务功能空间分异规律,参考现有生态服务功能的概念、内涵、分类等研究,提出淮河流域二级水生态服务功能体系。针对3类一级水生态服务功能和7种二级功能,分别给出其具体释义与简要特征描述。对淮河流域水生态特征的辨识与水生态服务功能的划分,可为流域生态建设与水资源保护奠定理论基础。     

中小河流治理水生态功能两级分区研究——以哈尔滨市蚂蚁河流域为例

面向中小河流生态治理需求,阐述了水生态功能分区的内涵,对分区指标体系的构建进行了探讨。基于Arc GIS空间分析平台,以哈尔滨市为对象,考虑气候、地形和人类活动因素,划分了哈尔滨市水生态功能一级分区。分析了蚂蚁河水生态服务功能和流域主要生态环境问题,选取径流深、坡度、地均GDP和水功能区指标,参照子流域及行政边界,划分了蚂蚁河流域水生态功能二级分区。根据水生态功能一级、二级分区结果,提出了哈尔滨市及蚂蚁河流域中小河流治理与保护方向,为该区域水陆一体化管理和生态环境综合治理提供了技术支撑。     

东辽河流域水生态功能分区研究

流域水生态功能分区是水环境、水生态系统管理的基础。综合考虑东辽河流域自然地理特征、水生态因子、社会经济活动影响和水生态服务功能等,确定了东辽河流域分区指标,运用地理信息系统空间分析和主成分分析等数学方法,对基础空间数据和流域水生态系统特征调查资料进行分析,提出了流域三级水生态功能分区方案,将东辽河流域划分为2个一级分区、4个二级分区、13个三级分区,利用底栖无脊椎动物的相关指标进行聚类分析,表明水生态功能三级分区是合理的。     

含水生植物河道曼宁糙率系数的试验研究

水生植物是河流生态系统的重要组成部分,但水生植物的存在使得水流阻力增加,河道行洪能力降低,开展含水生植物河道曼宁糙率系数的研究,对河流生态综合治理具有重要意义。本文基于对含淹没柔性水生植物水流的室内水槽系列试验和量纲分析理论,分析了植物挺立度、相对淹没高度及相对密植度对河道曼宁糙率的影响,给出了淹没状态下含柔性水生植物河道的通用等效曼宁糙率系数经验公式。     

HYDRAULIC RESISTANCE OF SUBMERGED VEGETATION RELATED TO EFFECTIVE HEIGHT

Submerged vegetation has a significant impact on water flow velocity. Current investigations include the impact through adding drag resistance and increasing bottom roughness coefficient, which cannot elucidate the characters of real submerged vegetation. To evaluate the effects of submerged vegetation on water currents at different velocities, a laboratory experiment was conducted using three kinds of vegetations. The effective heights of these vegetations on varying flow velocities were evaluated. An equation describing the relationship between the normalized resistance of the submerged plants and the Reynolds number based on the plant effective height was then established and used to calculate the hydraulic resistance parameters of submerged plants in different stages of growth.     

含柔性植物明渠水流阻力特性试验研究

利用水槽试验研究了无草、淹没型、非淹没型柔性植物水流阻力特性的变化规律,分析了含植物明渠沿程水面比降和阻力系数的变化特性。得到各植物阻力系数变化与尼库拉兹曲线基本相似,紊流范围内同样可划分为紊流光滑区、紊流过渡区、紊流粗糙区;探讨了各植物明渠等效河床的问题,据此确定了各植物的粗糙度,对植物粗糙度、水流雷诺数和阻力系数之间的关系进行了分析,并通过对各植物水流阻力系数的分区回归计算,得到各植物水流阻力的分区经验表达式,该方法能较好地应用于含植物明渠水流阻力系数的推求。