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31.
松嫩平原内陆盐碱湿地的类型特征及分布规律 总被引:3,自引:0,他引:3
内陆盐碱湿地是湿地的重要组成部分,其类型、特征及分布规律的研究十分薄弱。松嫩平原是世界上内陆盐碱湿地发育的典型地区之一。本文参考国内外湿地分类标准,结合松嫩平原的特点,建立了内陆盐碱湿地的分类体系,将该区的盐碱湿地划分为2个湿地类,6个湿地型,13个湿地亚型,描述了各类型的主要特征,并阐述了松嫩平原内陆盐碱湿地的分布规律。这对我国的湿地分类系统是一个重要的补充,对进一步实施内陆盐碱湿地的保护、恢复和重建,促进松嫩平原社会经济和环境的可持续发展都具有重要意义。 相似文献
32.
建立了一个数学模型来预测多氯联苯湿地生物降解过程。该模型全面考虑了多氯联苯湿地生物降解的各子过程,包括:吸附/解吸、土壤屏蔽、扩散和生物降解,利用模型,预测了多氯联苯湿地生物降解的规律性及处理时间、处理终点;利用Monte-Carlo法,进行了多氯联苯湿地生物降解污染风险分析,结果表明,在采用基地现有处理方式的情况下,经过8年处理,土壤中4-Cl-PCBs不低于69.4%被降解的可能性为75%,此时土壤中能够继续污染外部环境的4-Cl-PCBs部分不超过10.9%的可能性为75%;土壤中4-Cl-PCBs全部生物降解完毕所需处理时间不超过16.20年的可能性为75%,最后被土壤不可逆屏蔽的残余物不超过20.9%的可能性为75%。 相似文献
33.
34.
M. R. Handy 《International Journal of Earth Sciences》1996,85(4):832-851
The Zone of Samedan is part of a fossil, early Mesozoic rift system originally situated in the distal, Lower Austro-Alpine
domain of the Adriatic passive continental margin. An early Mesozoic configuration of asymmetrical rift basins bounded by
relative structural highs compartmentalized Late Cretaceous active margin tectonics; Jurassic half-grabens were folded into
arcuate synclines, whereas relative structural highs engendered thin, imbricated thrust sheets. West-directed thrusting and
folding initiated at the surface and continued to depths favoring mylonitization under lower greenschist-facies conditions.
At this time Liguria-Piemontese ophiolites were accreted to Lower Austro-Alpine units directly underlying the Zone of Samedan.
Late Cretaceous orogenic collapse of the Adriatic active margin involved the reactivation of west-directed thrusts as low-angle,
top-to-the-east, normal faults. These faults accommodated extensional uplift of Liguria-Piemontese ophiolites and Lower Austro-Alpine
units beneath and within the Zone of Samedan. During Paleogene collision, some Late Cretaceous faults in the Zone of Samedan
were reactivated under lower anchizonal conditions as north-directed thrusts. The latter stages of this early Tertiary thickening
were transitional to brittle, high-angle normal faulting associated with top-to-the-east extension and spreading above the
warm, uplifting Lepontine dome. 相似文献
35.
We have developed an algorithm that allows crosshole georadar amplitude data contaminated with systematic errors to be tomographically inverted. The effects of the errors, which may due to variable antenna-borehole coupling, the groundwater table, and 3-D heterogeneities in the vicinity of one or more boreholes, are included in a series of transmitter and receiver amplitude-correction factors. Tests with synthetic georadar sections demonstrate that the new approach is capable of producing reliable attenuation information, even when large systematic errors are present in the amplitude data. Standard inversions of crosshole georadar data acquired within a highly complex alpine rock glacier yield distorted tomograms. In contrast the new approach results in geologically useful images. 相似文献
36.
37.
乌拉苔草光合速率日变化及日同化量 总被引:10,自引:0,他引:10
乌拉苔草沼泽是长白山沟谷湿地的重要类型 ,对其光合速率研究的结果表明 ,乌拉苔草光合速率日变化呈单峰曲线 ,最高峰出现在 1 0时 ,最大值是 1 8.0 7μmol(CO2 ) / (m2 ·s) ;与其该群落伴生的修氏苔草光合速率日变化出现“午休”现象。影响光合速率最大的环境因素是光量子通量密度和叶温 ,呈极显著的正相关 ,其他因素亦多呈正相关 ,环境因子综合影响了乌拉苔草的光合日进程。乌拉苔草光合作用的日总同化量为 1 896 0 1 .2 μmol(CO2 ) /m2 ,是光合能力较强的一种沼泽植物 相似文献
38.
The Wilhelmine Alpe section near Immenstadt (Allgäu, south Germany), which represents one of the best continuously exposed outcrops within the northern Alpine foreland basin, has been analyzed for magnetostratigraphic and palynostratigraphic signals. The section comprises the marine-to-terrestrial transition from Lower Marine (UMM) to Lower Freshwater Molasse (USM) sediments. Based on the correlation of the local magnetic pattern with the geomagnetic polarity timescale (GPTS) and palynostratigraphic data, an age of about 31 Ma is suggested for the UMM–USM transition in the Wilhelmine Alpe section. A comparison with coeval magnetostratigraphic sections from central and eastern Switzerland indicates that the regression of the UMM sea along the southern margin of the Molasse basin occurred strongly heterochronously between 31.5 and 30 Ma. The heterochroneity is attributed to the deposition of fan-delta and alluvial fan sediments which document that the overall marine conditions during the UMM were accompanied by strong clastic input derived from the rising Alps. This clastic contribution had a much stronger influence on the depositional pattern than previously thought. 相似文献
39.
Intraplate deformation and 3D rheological structure of the Rhine Rift System and adjacent areas of the northern Alpine foreland 总被引:4,自引:0,他引:4
S. Cloetingh P. A. Ziegler F. Beekman P. A. M. Andriessen N. Hardebol P. Dèzes 《International Journal of Earth Sciences》2005,94(4):758-778
The lithosphere of the Northern Alpine foreland has undergone a polyphase evolution during which interacting stress-induced intraplate deformation and upper mantle thermal perturbations controlled folding of the thermally weakened lithosphere. In this paper we address relationships among deeper lithospheric processes, neotectonics and surface processes in the Northern Alpine foreland with special emphasis on tectonically induced topography. We focus on lithosphere memory and neotectonics, paying special attention to the thermo-mechanical structure of the Rhine Graben System and adjacent areas of the northern Alpine foreland lithosphere. We discuss implications for mechanisms of large-scale intraplate deformation and links with surface processes and topography evolution. 相似文献
40.