减轻二滩水库泥沙淤积的生态系统服务价值评估

基于ArcGIS 9.2,构建了生态系统减轻水库泥沙淤积的评估模型,并结合泥沙输移比（SDR）和通用水土流失方程（USLE）,模拟了二滩水库集水区的产沙量和保沙量及其空间分布特征以及水库使用年限内其生态系统服务价值.结果表明：2000年,二滩水库集水区土壤保持量12.1×10⁸ t·a^-1,土壤保持量高值区主要分布于雅砻江干流和支流水网附近;泥沙输移比的高值主要分布在河道附近和水库周边,水库周边是最主要的产沙区和保沙区;研究区实际产沙量为629.3×10⁴ t·a^-1,占实际土壤侵蚀量的12.7%;农田是研究区最主要的产沙源,其产沙量占集水区总产沙量的62.9%;林地平均单位面积的保沙价值最高.在二滩水库使用年限内（100 a）,集水区对于减轻二滩水库泥沙淤积的总价值为27.53亿元.     

泥沙输移比及其尺度依存研究进展

泥沙输移比是反映流域侵蚀产沙及输移能力的指标,对评价水土保持减沙效益有重要意义。基于对国内外泥沙输移比研究的系统梳理,1阐述了泥沙输移比的内涵,并对泥沙输移比基本定义中不同学科常用的表征变量作了清晰的界定,流域产沙量所涵尺度较流域输沙量小,且泥沙输移比与归槽率无论在内涵及定量描述上均不可等同;2归纳提出泥沙输移比现存的测算方法,包括4种形式的类比计算法和3种形式的建模计算法,并分别评述了其优缺点;3揭示了泥沙输移比的影响因素随时空尺度变化表现出分异性;4基于对泥沙输移比内涵与测算中的"尺度问题"以及泥沙输移比是否存在尺度效应等问题剖析,明确了泥沙输移比客观存在着尺度依存性及其尺度域。     

不同土地利用/覆被情景下生态系统减轻水库泥沙淤积的服务能力与经济价值模拟

以ArcGIS9.2为平台,构建了生态系统减轻水库泥沙淤积服务物质量和价值量评估模型.整合2000年的相关数据将此模型应用于二滩水库,并模拟了10种不同土地利用/覆被情景下集水区生态系统该项服务的能力和在水库使用年限内服务总价值的响应.结果表明:2000年,二滩水库集水区土壤保持量12.1亿t·a-1,高值区分布于雅砻江干流和支流水网附近.泥沙输移比在河道附近和水库周边较高.水库周边是最为主要的保沙区.水库使用年限内,集水区对于减轻二滩水库泥沙淤积服务总价值27.53亿元.集水区内不同结构类型的土地利用/覆被情景对保沙能力所产生的影响各异,模拟保沙量符合林地＞草地＞裸地＞农田规律,农田保沙能力最弱,是二滩水库最为主要的产沙源.     

城市雨洪SWMM 模型的敏感参数研究综述

伴随城市化的发展, 城市降雨径流水文机制发生改变, 城市内涝频繁发生和水质恶化严重, 最终造成城市水生态环境退化现象日益凸显。由美国EPA 研发的SWMM 模型成为城市降雨径流模拟研究的重要工具, 广泛应用于城市降雨径流产生、输移过程及其管理措施效果等方面的模拟研究, 但其参数的确定是其应用的关键性问题。可见, 对SWMM 模型敏感参数进行识别分类及其敏感性研究, 不仅有利于降低SWMM 模型应用时参数选取的工作量, 还可以提高其模拟结果的准确度。将SWMM 模型的主要敏感参数分为6 类: 汇水区性状参数、透水性地表与不透水性地表相关参数、下渗相关参数、传输模块参数、污染物累积冲刷相关参数和其他参数, 并分析得出敏感参数主要受模型输出变量类型、降雨强度和土地利用类型等因素的影响。在此基础上, 提出了针对SWMM 模型参数敏感性方面今后研究的重点, 以期为SWMM 模型在国内的应用与研究提供参考。     

流溪河水库沉积物粒度的时空分布及其沉积动力学意义

重建水库建库以来的沉积环境演变过程对水库管理具有重要意义。以流溪河水库4 个沉积物柱状样为研究对象, 分析沉积物的粒级组成及粒度参数特征。结果显示: (1)流溪河水库自建库以来, 沉积速率经历了“高-低-高-低”的演变规律; (2)河流是水库的主要沉积物来源, 沿入库口至大坝方向, 水动力逐渐减弱, 沉积颗粒呈现“由粗到细”的空间变化特征; (3)入库口(S3)主要受河流水动力作用影响; 库湾区(S8)远离入库口, 反映了稳定的湖心沉积环境; 过渡区(S4 和S6)受河流搬运营力、再沉积作用及库区消落带侵蚀的共同作用, 呈现由“双峰向单峰”的变化, 反映了上述三种主要营力互为消长的演变过程。     

风场对太湖叶绿素a空间分布的影响

叶绿素a的浓度是水环境评价的重要参数。根据2005—2009年太湖全湖32个采样点的20次太湖采样数据,结合气象要素资料模拟的太湖风场,探求了风场对太湖叶绿素a空间分布的影响。结果表明:叶绿素a浓度的高值中心位于太湖西北侧、竺山湾以及梅梁湾流域,而太湖东南部的叶绿素a浓度较低;全太湖全年以东南风为主,南部风速较大,北部风速较弱;风场对叶绿素a的输移作用明显,在风场作用下,叶绿素向太湖西北部和北部输移,造成了该地区太湖流域叶绿素浓度普遍偏高。     

北京半城子水库水体营养物质表观沉降速率

表观沉降速率是流域非点源污染模型中反映水体营养物质通过不同过程,输移进入水库沉积物净效果的参数。选择位于密云水库上游的半城子水库进行水体营养物质监测,计算营养物质表观沉降速率,分析其影响因素,主要得出以下结论:半城子水库TN表观沉降速率平均为55.5mm/d,TP表观沉降速率平均为25.2mm/d,相对于世界其它地区的湖泊水库而言,TP表观沉降速率较慢。水体营养物质表观沉降速率受表层水温和水流条件共同影响。TN表观沉降速率均随表层水温的升高而递增。上游来水后,水体中P元素则经历了内源磷快速释放,之后快速沉降的变化过程。研究成果可为水污染防治和流域环境综合治理提供理论依据。     

泽雅水库混合深度的年内变化及其对藻类生消影响

就水库藻类水华的发生机制而言,近年来值得关注的研究动向是,一些研究者开始认识到光照和混合的交互作用可能对藻类水华生消过程起到了关键作用,即认为水体混合深度的变化直接影响着可获得光强,从而决定着藻类生物量的时空分布。在这些研究中,混合层深度的确定是探讨藻类生消过程影响的前提。然而已有的研究大都只进行粗略的估计。本文提出采取系统聚类分析的方法确定泽雅水库不同时期的混合深度。在具体分析过程中,将测得的某一天某一深度处的pH,DO,温度,电导率,氧化还原电位等5个参数结果看成一类,采用类间平均连接法,间隔尺度变量为欧氏距离的平方进行聚类。对采用系统聚类分析法和已有的"1°C"法计算得的全年的混合深度的变化趋势进行比较,认为系统聚类分析法可以更为准确地反应水体混合的实际情况。依据混合深度的不同特征,在年内水库水体可划分为热成层时期,全混时期和两者之间的过渡期,藻类生物量与混合深度呈负相关。在热成层期间,藻类生物量都超过了13mm³L^-1。而到了9月份,当混合层深度扩展到15m以上时,藻类生物量明显下降,此后水体处于全混时期,藻类生物量较低,在9-20mm³/L^-1波动。基于稳态假设的前提下,发现随着混合深度增加,稳态藻类生物量呈单峰变化,在混合深度2m处达到最大值,即在混合深度为0-2m之间时,藻类沉降作用是藻类生物量的主要影响因素,随着深度增加,沉降作用下降,因此藻类生物量增加;当混合深度超过2m之后,光限制作用占主导因素,藻类生物量随混合深度增加而下降。这一结果为 Diehl的假说提供了水库现场的实证。     

在扎龙保护区内进行苍鹭与草鹭间移巢易亲的实验研究

1986年5、6月间在扎龙保护区内,采取移卵、移换雏鸟,移换鸟巢等方法在苍鹭与草鹭之间进行的移巢易亲的研究结果报告。这个实验对鹭属形态与生态习性相近的两个种间移巢易亲后,义亲的产卵孵化、育雏等行为以及义子卵的孵化、雏鸟生长发育等根据实验结果做了客观分析、并对实验中7只雏鸟(2只苍鹭、5只草鹭)做了环志,为进一步研究这两种鹭的迁徙行为研究提供一些可能有用的线索。     

黄土丘陵沟壑区景观格局对流域侵蚀产沙过程的影响——斑块类型水平

在黄土丘陵沟壑区,景观格局对侵蚀产沙过程有着复杂的影响,且与尺度密切相关。选取河口-龙门区间内42个水文站控制流域为研究对象,以侵蚀模数、输沙模数和泥沙输移比作为表征各流域单元内土壤侵蚀、产沙及泥沙输移过程的特征指标,运用景观指数和CCA排序,系统分析了斑块类型水平上景观格局对流域侵蚀产沙过程的影响。结果表明:流域侵蚀产沙及泥沙输移过程中,空间分异特征随景观类型不同而异;对于不同用地类型,影响"过程"空间分异的景观格局指标不同,显著影响流域侵蚀产沙及泥沙输移过程的景观指数有草地平均斑块面积(AREA_MN3)、居民建设用地景观面积百分比(PLAND5)、居民建设用地和其它类型用地景观的斑块密度(PD5和PD6),其中斑块密度(PD)是影响流域侵蚀产沙及泥沙输移过程的共性指标;草地、居民建设用地、其它类型用地的景观格局特征对"过程"变化的解释程度要高于其它景观类型。开展景观格局与生态过程关系研究时,不仅需要考虑景观格局的整体效应,更应关注单一景观类型及其格局特征对一些生态过程的指示意义。     

A numerical model for fine suspended sediment transport in the southwest lagoon of New Caledonia

A hydrodynamic-transport coupled model is used to understand the transport of fine suspended sediments in the southwest lagoon of New Caledonia. The hydrodynamic model is briefly presented and the circulation due to the tide and to averaged trade wind forcings is analyzed. The transport model for fine suspended sediment is described. Parameters involved in this model (settling velocity, critical shear stresses, erosion rate coefficient, Schmidt number) are discussed and a calibration procedure is proposed. Using the resultant parameters, the erosion and deposition areas predicted by the sediment-transport model are in very good agreement with the distribution of the percentage of mud at the seabed. The sensitivity of the model to the different sedimentary parameters is studied, and the influences of the tide and wind on deposition and erosion are discussed. The influence of the wind is dominant in seabed exchange processes in shallow areas and produces large erosion rates where the water depth is less than 20 m. The tide controls the particulate transport, vertical mixing, and deposition rates in the areas where the influence of the wind is weak.     

Seasonal variation of mixing depth and its influence on phytoplankton dynamics in the Zeya reservoir, China

In reservoirs or lakes, mixing depth affects growth and loss rates of phytoplankton populations. Based on 1-year data from the Zeya reservoir, China, we scaled the mixing depth throughout a whole year by utilizing cluster analysis, and then investigated its influence on phytoplankton dynamics and other physical and chemical parameters. Over the whole year, all physical and chemical parameters except TN and temperature had significant correlations with mixing depth, indicating that mixing depth is one of the important driving factors influencing water environment. According to mixing depth, a year can be divided into three different periods, including the thermally stratified period, isothermally mixed period, and transition period between them. When considering the former two different periods separately, mixing depth had no correlation with the phytoplankton biovolume. However, over the whole year a significant correlation was observed, which indicated that the influence of mixing depth on phytoplankton growth in the Zeya reservoir still followed Diehl’s theory. Furthermore, according to the steady-state assumption, a unimodal curve (mixing depth—phytoplankton biovolume) with a significant peak appearing at a mixing depth of 2 m was observed, closely agreeing with Diehl’ prediction.     

Spatial Heterogeneity of Cyanobacteria and Diatoms in a Thermally Stratified Canyon‐Shaped Reservoir

Phytoplankton communities in lakes and reservoirs are seldom homogeneously distributed but usually aggregate in patches and gradients. In this study we have combined the use of in vivo spectrofluorometry and acoustic Doppler current profiling to investigate the effect of water movements on the spatial distribution of cyanobacteria and diatoms in a thermally stratified reservoir in SW Spain. The distinctive canyon‐shaped morphometry of the reservoir (El Gergal) favoured the development of a “conveyor belt” pattern of circulation aligned with the long axis of the reservoir. Under non‐regulated conditions, the spatial distribution of phytoplankton was almost entirely dependent on the interactions between advective transport and the buoyancy properties of the different functional groups of phytoplankton. The positively‐buoyant cyanobacteria accumulated near the surface and were then transported downwind by the surface drift currents. In contrast, the negatively‐buoyant diatoms sank in the water column and were transported upwind by the sub‐surface return currents. When deep water was abstracted from the reservoir, these distribution patterns were modified. The results are discussed in relation to the problem of acquiring representative water samples from the reservoir and the application of a simple empirical model to optimize the location of the station used for routine cyanobacteria sampling on the reservoir. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

广州抽水蓄能电站蓄水库蓄水初期浮游生物调查

对我国首座核电站配套工程的抽水蓄能电站水库蓄水初期的浮游生物进行了调查。蓄水水库由上下两水库组成。两水库的浮游生物种类组成显著不同。上水库浮游植物共记录到３０种（属）,浮游动物１２种（属）;下水库浮游植物１９种（属）;浮游动物２５种（属）。上下两水库浮游生物数量均较贫乏,表明浮游生物群落尚处于初期发育阶段,但在局部浅水处已出现小规模的蓝藻水花,认为是水库蓄水初期必然的结果     

珠江佛山与广州交界河段潮水河水质水量监测与评价

受潮汐的影响,潮水河中污染物的迁移和变化规律极其复杂。针对这一问题,开展如何布设合理的监测断面,制定合乎潮汐规律的潮水河水质水量同步监测方案等方面的研究,更好地为摸清潮水河段的污染物输入量以及河流的水质状况服务。通过对佛山与广州交界潮水河段水质水量的同步监测发现:该区域日化学需氧量输入量为288.8t,日氨氮输入量为88.8t;采用代表时段法计算出污染物的输入量及采用单项指标法评价潮水河水体现状比较可靠、合理;纳污量超过河段环境容量是导致水质不断恶化的原因;加强交界河段上游地区面污染治理,建立重点取水水源地水质自动监测站,对水源地水质状况实时监测,是保证不同季节取水安全的有效措施。     

Hydropower-related mortality and behaviour of Atlantic salmon smolts in the River Sieg,a German tributary to the Rhine

We studied downstream migration of 256 radio-tagged Atlantic salmon smolts passing a low-head power station where technical facilities have been improved to allow safe migration via several bypass routes. Extra mortality was 7 and 17% (two years) in the power station reservoir, and a minimum of 10 and 13% at the power station compared to in a control stretch. The majority of the smolts followed the main flow at the power station, towards the turbines. Sloped bar racks with 10 mm bar spacing hindered smolts from entering the turbines, hence there was no turbine mortality. Smolts used surface openings in the racks, which directed them to a bypass route outside the turbines. The extra mortality in the reservoir and at the power station was related to physical injuries in bypass routes and to predation. The mortality risk in the reservoir and at the power station decreased with increasing migration speed. Migration speeds increased with water discharge. Migration was slower when the smolts passed the power station than on other stretches. This study shows that hydropower regulation caused elevated mortality and delays for downstream migrating fish, even with improved technical facilities to reduce mortality.     

一种毛翅目昆虫的生态治理研究

针对生活在水流速度较快的湖南省柘溪水电站一带河床大量发生的原双栖纹石蛾(Amphipsyche proluta)来说采用一般的防治措施都很难付诸实施,或者只能是治标,不能治本。经1997年至2000年的调查研究和试验分析得知人为去掉河底大型石块,加深河水深度,减缓流速,以破坏适宜于该石蛾幼虫生存的生态环境,引进生态致死因子,是从根本上杜绝该石蛾发生的较为理想的办法。     

水深对塘堰湿地水力性能的影响

塘堰湿地因其良好的生态性能而被广泛用于水稻灌区的排水净化,由于湿地的水力性能及净化效果受到诸多因素影响,客观认识这些因素的作用机理有助于提高湿地设计和运行管理的质量.本文通过示踪剂试验探讨了不同水深（20、40、60 cm）对塘堰湿地水力特性的影响.结果表明： 随着湿地水深的减小,湿地的有效容积率从0.421增加到0.844,水力效率从0.281增加到0.604;在水深较小时（20和40 cm）,湿地前半部分的有效容积率达到0.9以上,明显优于湿地整体情况,湿地前半部分的水流混合情况高,接近于完全混合流.通过对原始示踪曲线的标准化分析发现,矩分析参数与水力参数有较好的数值一致性,水力参数与不受尾部截断误差影响的矩指数之间具有良好的一致性.塘堰湿地水深较小时有利于提高湿地的水力性能,试验结果可为今后塘堰湿地的优化设计提供参考.     

Spatial and temporal variation in the summer zooplankton community of a riverine reservoir

Zooplankton community structure was examined at five stations in Normandy Reservoir, Tennessee, on six dates from 11 July to 15 September 1980. Four physical and chemical parameters at three depths at each station were used to discriminate statistically among areas of the reservoir over time; a similar analysis based on nine taxonomic and ecological categories of zooplankton was also completed. Each of the two multi-variate analyses provided a matrix of similarities among station-times (n = 30) in the reservoir. The two similarity matrices were compared by the Mantel test and were found to be not significantly concordant, suggesting that physical-chemical variation among areas in the reservoir during the summer months was not precisely reflected by zooplankton community structure. The lack of congruence between physically- and chemically-determined reservoir structure and structure implied by zooplankton taxa or functional groups was also observed in the results of a random-effects-model ANOVA of physical and chemical parameters and zooplankton densities. ANOVA of zooplankton densities revealed that spatial variation was generally greater than temporal variation, although most of the spatial variation was ephemeral (station-time interaction) rather than fixed (station effects). An ANOVA of physical and chemical variables revealed considerable fixed spatial variation over the same time scale.     

水生生态系统的碳循环及对大气CO2的汇

水生生态系统,特别是海洋无疑是大气CO2的一个巨大的汇。海洋对大气CO2的汇以及大气圈和海洋之间碳的变换量在很大程度上取于混合层碳酸盐化学、水中溶解碳的平流传输、CO2通过空气－－海水界面的扩散、海洋生物生产和所产生的有面碳化合物的沉隆等,现在已建立和发展了多种海洋碳子模型以对CO2的汇进行估测。根据国内外研究资料,综述了水生生态系统碳循环过程及“生物泵”作用机制等方面的研究进展;介绍了两大类主要的海洋碳子模型：厢式模型和普通环流模型,采用这些模型对海洋碳汇的估算约为1.2-2.4GtC/a;分析了湖泊、河流等对大气CO2汇的特点及向海洋的转移,并对影响水体生态系统碳循环和大气CO2汇的因素进行了讨论。