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1.
为了解极端旱情对新丰江水库的浮游植物功能群(functional group)的演替规律及驱动机制,在干旱期以月为频次开展浮游植物和水质调查。结果表明,水库旱情期(2021年)浮游植物功能群可归类为23个,其中功能群A/E/F/J/K/Lo/M/MP/NA/P/SN/TB/X1/X2/X3/Y频率较高,且A/E/F/J/Lo/MP/P/X3/Y为优势功能群,水库功能群变化趋势为A/E/MP/P/X3(1月)→E/Lo/MP(2月)→A/E/Lo(3月)→A/E/Lo(4月)→A/Lo(5月)→A/Lo/Y(6月)→A/F/Lo/MP/Y(7月)→A/F/Lo/Y(8月)→A/F/Lo(9月)→A/F/Lo/MP(10月)→A/E/F/Lo/MP/Y(11月)→A/E/Lo(12月)。适应贫营养生境的功能群A/E/Lo/Y等为旱情期藻类群落结构的主体优势类群。相关分析(Spearman)和冗余分析(RDA)结果表明,旱情期影响水库浮游植物功能群组成的主要驱动因子是水温和透明度。水库月度生态状态指数(Q)值范围为4.07~4.87,达到极好水平,说明旱情对新丰江水库浮游植物群落结构影响相对较弱。  相似文献   

2.
洪水事件能够在短时间内对生态系统的物理与生物过程产生重大影响,从而导致浮游植物群落结构的快速演替.2010年9月,广东省大型水库——高州水库发生特大洪水.为了解洪水的生态效应,于2010年1月-2011年12月对高州水库湖沼学变量和浮游植物进行了调查研究.特大洪水期间,高州水库流域内大量泥沙等颗粒物进入水体,将原有有机物相对较多的沉积物覆盖,有助于减少营养盐的底泥释放,洪水后次年春季枯水期水体营养盐浓度明显降低(尤其是磷,总磷浓度低于0.01 mg/L).洪水过后水体中悬浮物的组成改变,在接下来的水体混合期间无机颗粒物的再悬浮导致水体透明度显著降低,但次年水库整体的透明度升高,浮游植物生物量降低.洪水事件导致的水体理化环境的改变使水库浮游植物群落结构改变,由洪水前以群体蓝藻和大个体绿藻(H1和N A功能类群)为优势类群的群落转变为洪水后以中心纲浮游硅藻和甲藻(A、B和LO功能类群)为优势类群的群落,而以往枯水期常有发生的粘质鱼腥藻等蓝藻水华在洪水后春季枯水期没有出现.  相似文献   

3.
为了解西藏拉鲁湿地浮游植物群落时空分布特征及其驱动因子,于2021年7月、10月和2022年5月在拉鲁湿地主要水系进行定性和定量样品采集,共采集浮游植物水样126个,从不同季节和不同生境浮游植物种类组成、多样性等方面入手,探讨拉鲁湿地浮游植物群落时空分布特征及其驱动因子,为研究拉鲁湿地生态系统和稳定发展提供基础资料。结果表明:1)拉鲁湿地共鉴定出浮游植物532种(含变种和变型),隶属于8门13纲36目74科130属,物种组成表现为硅藻-绿藻-蓝藻型。2)拉鲁湿地浮游植物群落特征参数在不同季节和不同生境之间存在差异。夏季浮游植物群落的Shannon-Wiener多样性指数显著高于秋季和春季,Simpson优势度指数显著高于秋季。秋季浮游植物群落的Pielou均匀度指数显著低于夏季和春季。春季浮游植物群落的Margalef丰富度指数显著低于夏季和秋季。沼泽生境的浮游植物群落的Margalef丰富度指数显著高于湿草甸生境。3)季节是浮游植物群落组成差异的关键因素,生境对浮游植物群落组成的影响较弱,夏季的距离衰减模式比秋季和春季更强。4)拉鲁湿地不同的浮游植物群落参数与不同环境因子之间存在显著的关联。5)空间因素在解释浮游植物群落变异方面具有显著贡献,而快速变化的水质变量在决定浮游植物的季节变化中起着重要作用。季节和缓慢变化水质因子的解释能力相对较弱,但仍对浮游植物群落的变异有一定影响。  相似文献   

4.
丹江口水库是南水北调中线工程水源地,库湾是水库型湖泊水质安全敏感区,动态调水过程库湾水质直接关系到调水安全.为探究动态调水过程中丹江口水库库湾浮游植物季节变化规律和驱动因子,2018年7月—2019年7月,从丹库入库口到渠首调水口,按季节对18个样点进行水质和浮游植物群落组成分析.从整个丹库来看,浮游植物全年总丰度变化范围为0.43×10~3~4.7× 10~6 cells/L,夏季最高,秋季最低;Shannon-Wiener指数春季最高,秋季最低.春季群落为硅藻—绿藻型,夏季为绿藻—硅藻型,秋季为蓝藻型,冬季为蓝藻—绿藻—硅藻型,秋季蓝藻相对丰度最高.位于丹库准保护区内的库湾胡寨,秋季水体电导率、总氮、总磷和叶绿素a浓度最大,蓝藻丰度最高.从入库口经库湾到调水口,浮游植物群落组成存在明显演替.从水文因子来看,秋季水库水位较高,调水流速和流量增加,线性回归分析表明,水位对ShannonWiener指数的影响最为明显,水位越高则多样性指数越低;流量和流速与Shannon-Wiener指数也呈负相关,但相关性较低.方差分解分析发现,水文因子和理化因子共同影响了浮游植物群落组成;偏Mantel分析显示3个库湾浮游植物群落组成与水温、氧化还原电位、化学需氧量、总氮和总磷浓度相关;典范对应分析也表明,总氮是影响库湾浮游植物群落组成最显著的环境因子.人类干扰活动改变了库湾水质理化性质,强干扰提高了蓝藻门丰度.因此,控制库湾人类干扰强度,尤其在水位和调水量较高的秋季,对于改善水体藻类组成、保护整个丹江口水库水质具有重要意义.  相似文献   

5.
为了解黔中地区浮游植物群落结构特征,同时为了研究功能群对水环境的指示,选取黔中2座典型水库——普定水库和桂家湖水库,分别于2015年的枯水期(1月)和丰水期(8月)进行浮游植物采样分析.结果表明:(1)2座水库营养盐无显著性差异,水动力学参数(水温、混合层深度、透明度、真光层深度、水柱相对稳定性、光的可获得性)存在显著性差异.(2)普定水库共归类出18个功能类群,桂家湖水库共归类出15个功能类群.普定水库优势功能群水期分布特征:枯水期LO→丰水期B+P;桂家湖水库优势功能群水期分布特征:枯水期B+J+Y→丰水期B+J.垂直层面上,普定水库枯水期以甲藻组成的优势功能群LO在三岔街采样点表层藻类生物量达到峰值(18529μg/L),远高于中层和底层水体以及其他采样点,与该点水文特性以及组成LO的甲藻特征有关.丰水期以硅藻组成的功能群P在小河采样点的中层藻类生物量最大(2741μg/L),远高于该点的表层水体及其他采样点,与P类群耐受低光有关.而桂家湖水库由于面积小、水位浅且少有人为干扰,故样点间环境因子差异小,整个水体优势功能群分布高度一致.(3)经RDA分析,水动力学参数、营养盐、p H和电导率是影响普定水库浮游植物群落分布的主要环境因子;桂家湖水库仅水动力学参数(水温和水柱相对稳定性)是主要因子.(4)从浮游植物功能群适宜生境来看,普定水库为富营养水体,桂家湖水库为中到富营养水体.由分析得出隶属于不同水域的2座水库浮游植物群落结构及水环境均存在显著性差异.  相似文献   

6.
为了掌握富春江水库浮游植物群落特征,探寻其与环境因子的关系,于2006年1月至2007年12月,对其进行了20次采样调查.鉴定结果表明富春江水库共有浮游植物107种,浮游植物密度范围在0.21×10~5-3.01×10~7cells/L之间.浮游植物组成随季节变化有所不同,春季绿藻、隐藻、硅藻占优势,夏季蓝藻和硅藻占优势,秋冬季硅藻、隐藻占优势.浮游植物群落结构受水文条件的影响较大,浮游植物密度与水体温度呈显著正相关,与透明度在不同范围内表现出不同的相关关系;与TN、TP在不同范围内表现出不同的相关关系,与TN/TP及可溶性硅呈显著正相关.库区总氮和总磷浓度均很高,足够满足藻类生长需要;TN/TP较低,基本在8-30之间,说明氮磷含量不是富春江库区藻类生长的限制因子.水文季节性变化会明显地影响浮游植物群落结构和密度的季节性变化,特别是降雨、水温及水力滞留时间等因子是影响水库浮游植物群落结构及密度变化的主要因子.  相似文献   

7.
太湖梅梁湾与五里湖浮游植物群落的比较   总被引:19,自引:4,他引:15  
富营养化和风浪是影响大型浅水湖泊浮游植物群落的重要因素,本文于2003年10月至2004年9月对太湖梅梁湾和五里湖理化环境因子(水温、透明度值、悬浮质浓度和氮、磷营养盐浓度)和浮游植物群落进行了逐月监测,通过对两个湖区理化因子和浮游植物群落结构在周年内季节变化的比较研究,探讨富营养化程度以及风浪对浮游植物群落结构的影响,结果为:(1)梅梁湾由于受风浪影响悬浮物含量较高,五里湖则富营养化水平更高.(2)周年内五里湖浮游植物平均生物量(6.85 mg/L)高于梅梁湾的平均生物量(4.99 mg/L),两个湖区都呈现夏秋高峰、冬季低谷的变化特征.梅梁湾浮游植物群落季节演替的模式基本为:冬季硅藻(小环藻属Cyclotella spp.)和隐藻(隐藻属Cryptomonas spp.)-春季绿藻(细丝藻属Planctonema sp.)-夏季绿藻(绿球藻目Chlorococcales种类)和蓝藻(微囊藻属Microcystis spp.和浮游蓝丝藻属Planktothrix spp.)-初秋蓝藻(微囊藻属)和硅藻(浮游直链硅藻Aulacoseira spp.)-秋季隐藻(隐藻属).五里湖的季节演替模式没有梅梁湾明显,全年隐藻(隐藻属)都占优势,在此基础上,秋冬季硅藻(小环藻属和浮游直链硅藻属)占优势,裸藻(裸藻属Euglena spp.)在冬春季占优势,绿藻(绿球藻目种类和团藻目衣藻属Chlamydomonas spp.)在整个春季和初夏的优势地位在夏季被蓝藻(微囊藻属和浮游蓝丝藻属)所取代.群落构成的差异是浮游植物对两个湖区不同风浪条件和富营养化水平的响应结果.(3)通过与PEG(Plankton Ecology Group)模式的比较,梅梁湾和五里湖浮游植物群落的季节演替主要受水温、光照、营养盐(氮、磷)浓度和浮游动物牧食等因子的影响,因此,大型富营养化浅水湖泊浮游植物群落演替规律需要进一步的研究.  相似文献   

8.
为探明长江中游大型水库水质状况,并为饮用水源安全保障提供科学依据,于2013 2014年按季节对湖北红安金沙河水库浮游植物群落结构及其多样性进行调查,并运用多元统计定量分析浮游植物群落结构与环境因子之间的关系.共鉴定出浮游植物8门94属216种,其中绿藻门为优势种群,其种类数占总物种数的51.39%,其次是硅藻门和蓝藻门.金沙河水库优势种随季节变化而变化,夏季以尖针杆藻(Synedra acus)的优势度最大(0.195),秋季以小胶鞘藻(Phormidium tenus)(0.180)和中华尖头藻(Raphidiopsis sinensia)(0.171)的优势度最大,冬季以具星小环藻(Cyclotella stelligera)(0.220)和圆筒锥囊藻(Dinobryon cylindricum)(0.234)的优势度最大,春季则是链状曲壳藻(Achanthidum catenatum)成为绝对优势种(0.910);金沙河水库浮游植物群落总的变化规律为夏季的硅藻门、蓝藻门和绿藻门,秋季的蓝藻门、绿藻门、硅藻门和隐藻门,向冬季的硅藻门和金藻门转变,春季则是硅藻门为绝对优势类群.Shannon-Wiener多样性指数和Pielou均匀度指数显示,浮游植物在秋季的多样性和均匀度较高,春季的多样性指数和均匀度指数显著低于其它季节,这是因为春季有绝对单一的优势物种,而秋季没有,且秋季的物种数最多,因此其Margalef丰富度指数也最高.将各季节优势种和经Pearson相关性分析筛选出的环境因子进行冗余分析,结果表明筛选的环境因子中磷酸盐、总磷和溶解氧浓度是影响金沙河水库浮游植物群落结构的主要环境因子.从藻类季节变化规律来看,金沙河水库夏、秋季水质污染程度较春、冬季严重;但从藻类丰度和多样性指数来看,春、夏季水质较秋、冬季污染严重.  相似文献   

9.
为探究呼伦湖浮游植物群落的季节变化特征及其与环境因子的关系,本研究分别于2019年3、5—10月对呼伦湖浮游植物的种类、细胞密度和生物量及湖水水质进行调查.结果显示,共鉴定出120种浮游植物,隶属于7门72属.从浮游植物群落季节组成差异上来看,春季绿藻门种类数最多,其次是硅藻门、蓝藻门;夏秋季绿藻门种类数最多,蓝藻门次之;冬季硅藻门种类数最多,绿藻门次之.呼伦湖浮游植物优势种主要为硅藻门的梅尼小环藻(Cyclotella meneghiniana)、蓝藻门的卷曲长孢藻(Anabaena circinalis)和细小平裂藻(Merismopedia minima),种类数在春季最多,秋冬季最少.浮游植物细胞密度在春季(123.52×104 cells/L)和冬季(16.41×104 cells/L)较夏季(280.80×104 cells/L)和秋季(380.63×104 cells/L)低,春冬季绿藻门细胞密度最高,夏秋季蓝藻门细胞密度最高.就浮游植物生物量而言,夏季(0.38 mg/L)最大,其次是秋季(0.26 mg/L)和春季(0.24 mg/L),冬季(0.13 mg/L)最小.香农-威纳(Shannon-Wiener)多样性指数、均匀度指数和综合营养状态指数均表明呼伦湖水体处于中营养状态.冗余分析(RDA)表明:水温、叶绿素a、pH和营养盐浓度是影响呼伦湖浮游植物群落分布的主要环境因子.  相似文献   

10.
研究丹江口水库在完成高水位蓄水期间浮游植物群落的时空动态特征可为丹江口水库的水质保护与生态系统结构优化及健康管理提供一定科学依据。本研究基于2018—2020年的水库浮游植物监测数据,结合同期水库水体的理化参数,分析了丹江口水库浮游植物在不同年度、季度及空间的变化特征,以及影响浮游植物群落结构变化的主要环境因子。结果显示该区域共检测出浮游植物7个门类,其中蓝藻门、硅藻门、绿藻门、隐藻门为优势类群。2018—2020年浮游植物年均密度分别为1.96×106、2.55×106和5.07×106 cells/L,呈现出逐年增高趋势。浮游植物季度密度表现为秋季>夏季>春季>冬季,在夏秋季节蓝藻门和绿藻门占优势,春冬季节硅藻门和隐藻门占优势,同时硅藻门在四季中均占据生长优势。空间上库区浮游植物密度明显高于支流,且汉江库区浮游植物密度高于丹江库区,其中蓝藻门和绿藻门主要在库区大量出现,而支流则以硅藻门和隐藻门为主。RDA分析显示,影响丹江口水库浮游植物的主要环境因子是水温,其次为化学需氧量、氨氮和总磷。在不同季节和...  相似文献   

11.
In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations (CSs), as well as discharge and sediment transport at 3 Gauging Stations (GSs) are used to assess the features of sediment transport in the Kuye River. The rtmoff modulus (defined as the annual average discharge per unit area, L/(s·km^2)) and the sediment transport modulus (defined as the annual suspended sediment transport per unit area, t/(yr km^2)) are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m^3/s in August with an average monthly sediment concentration of 88.9 kg/m^3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m^3 and occurs in July, which has an average discharge of 42.6 m^3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye River is largest in February and then decreases until June. In July, the average monthly median grain size of suspended load approaches another peak and decreases until September. Then, the median grain size of suspended load starts to increase until February of the following year. However, the average monthly median grain size of suspended load in the Yellow River at Toudaoguai and Longmen GSs is the smallest between early summer and late fall The median grain size in the Yellow River starts to increase in November and approaches the largest size in January.  相似文献   

12.
Observations of trace gases (SO2, NH3, NO2 and O3) were made during the period 1981 to 1984 at 6 different locations representative of urban industrial, urban, nonurban, thermal power plant and marine environment. Diurnal variations of the trace gases were studied in an urban environment. Except in the urban industrial environment, the concentration of NH3 was found in the range of background values. Also, the average concentrations of NO2 and O3 at the different environments were in the order of background values. However, the concentrations of SO2 were substantially higher by about 7 times, in urban industrial and thermal power plant environments. The diurnal variations of SO2, NH3 and NO2 showed anitphase relationship with surface temperature at the urban environment station which is relatively free of industrial pollution. Discussion is centred on trace gas variations in different environments in India together with the values reported for various countries in the world.  相似文献   

13.
3He/4He ratios up to 3.5 times the ratio of atmospheric He were found in groundwater samples. The3He enrichment can be attributed to radiogenic3He produced by in-situ beta-decay of3H. This shows that tritiogenic3He is accumulating in confined waters. From tritiogenic3He and3H concentrations, ages of groundwaters can be calculated. Detection of tritiogenic3He gives a tool to trace a tritium contamination which occurred in the past and cannot be assessed only by the3H counting method.  相似文献   

14.
15.
2008年云南地震灾害概况   总被引:1,自引:1,他引:0  
列出了2008年云南省破坏性地震目录.在此基础上,结合云南省地震局的地震灾害评估资料,总结了2008年云南地震灾害的主要数据和特性.最后列出1990~2008年云南地震灾害的相应数据,并进行了简要对比.  相似文献   

16.
In an active spreading area like Iceland, where the regional geothermal gradient is in the range 50–150°C/km, it is normally not a problem to find high enough temperature with deep drilling, but the difficulties arise with finding permeable layers at depth within the strata. Various volcanological methods can be applied in the search for aquifers and geothermal reservoir rocks. The flow pattern (as deduced from deuterium studies) indicates that the thermal water flows preferentially along high porosity stratiform horizons and dyke swarms from the recharge areas in the highlands to the hot spring areas in the lowlands. The primary porosity of the volcanic strata is dependent on the chemical composition and the mode of eruption of the volcanic units. Both the reservoir rocks and the flow channels forming the geothermal plumbing system are thought to vary from the Tertiary to the Quaternary provinces due to environmental conditions at the eruptive sites.  相似文献   

17.
2007年中国大陆地震灾害损失述评   总被引:4,自引:0,他引:4  
在列出2007年中国5级以上地震目录的基础上,结合有关省(自治区、直辖市)地震局的地震灾害评估资料,总结出2007年中国大陆地震灾害的主要数据和特性。最后列出1990—2007年中国大陆地震灾害的相应数据,并进行了简要的比较。  相似文献   

18.
The aim of this study is to estimate likely changes in flood indices under a future climate and to assess the uncertainty in these estimates for selected catchments in Poland. Precipitation and temperature time series from climate simulations from the EURO-CORDEX initiative for the periods 1971–2000, 2021–2050 and 2071–2100 following the RCP4.5 and RCP8.5 emission scenarios have been used to produce hydrological simulations based on the HBV hydrological model. As the climate model outputs for Poland are highly biased, post processing in the form of bias correction was first performed so that the climate time series could be applied in hydrological simulations at a catchment-scale. The results indicate that bias correction significantly improves flow simulations and estimated flood indices based on comparisons with simulations from observed climate data for the control period. The estimated changes in the mean annual flood and in flood quantiles under a future climate indicate a large spread in the estimates both within and between the catchments. An ANOVA analysis was used to assess the relative contributions of the 2 emission scenarios, the 7 climate models and the 4 bias correction methods to the total spread in the projected changes in extreme river flow indices for each catchment. The analysis indicates that the differences between climate models generally make the largest contribution to the spread in the ensemble of the three factors considered. The results for bias corrected data show small differences between the four bias correction methods considered, and, in contrast with the results for uncorrected simulations, project increases in flood indices for most catchments under a future climate.  相似文献   

19.
冬季亚洲中强震与夏季我国东部主雨带的准同纬性   总被引:2,自引:1,他引:1       下载免费PDF全文
根据1954~2003年50年亚洲中强震与我国地温资料,分析了冬季震中纬度—震涡中心纬度—冬季我国东部强地热涡中心纬度—夏季我国东部主雨带纬度4者之间的相互关系,发现冬季中强震与夏季主雨带之间具有较好的准同纬性. 这是每年汛期降水预报的一个指标. 文中也讨论了应用此预报指标时的一些特例.  相似文献   

20.
This paper briefly summarizes the works in the processing of strong ground motion data, the factors affecting strong ground motion, the modeling of strong ground motion and the calculating of broad-band response spectrum which have been done recent years by engineering seismologists and seismologists of China. In addition, we think back to the international cooperation in strong ground motion of the recent years and make some expectations for the future.  相似文献   

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