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11.
运用经验正交函数（EOF）和交叉小波变换法,分析了湖南省1981―2013 年月蒸发量的时空分布特征及其与月平均气温之间的非线性交互关系。月蒸发量的EOF 分解表明：前3 个空间模态的累计贡献率达77.9%。其中EOF1（63.4%）揭示了湖南省月蒸发量最主要的时空分布特征呈东西反向型,体现出月蒸发量与高程之间存在一定的负相关性;EOF2（8.5%）具有正负位相频繁交替的时间系数,反映了更为复杂的时空变化特征;EOF3（6.0%）的值自西北向东南呈“＋、-、＋”分布。然后,分别选用洪江、桑植和新晃站作为3 个空间模态的代表站点,并计算出各站点的月蒸发量与月平均气温之间的交叉小波谱和小波一致性,结果表明：两者之间的相关性在8~16个月的时间尺度下最强,且其相位角均为0°,说明气温对蒸发量的影响在该时间尺度下最为显著且不存在时滞效应,但在＜8 个月和＞16 个月的时间尺度下,强相关性的出现频率和分布以及相位角的方向沿时间轴均呈现出较大的差异性。 相似文献
13.
利用数据跟踪分析信息库,提取2017年8月9日精河6.6级地震前3个月,距震中500 km范围内的观测数据跟踪分析记录,对与地震相关的不明原因事件进行分析讨论。结果表明：精河地震发生前,温泉地震台水平摆、精河地震台水平摆、博乐32井水位出现不明原因的疑似前兆异常变化,地震结束后逐渐恢复正常。巴仑台地震台分量应变在此次地震前也出现不明原因变化,但地震结束后异常持续变化,需后续重点跟踪分析。 相似文献
14.
As one of the lakes on the Yunnan-Guizhou plateau, Lake Chenghai, which is a typical closed lake with the precipitation accounting
for one-third or more of the annual water input, has a high total salinity (almost like a saline lake). The inorganic C, O
isotopic composition of lake sediments bears much sensitive information about environmental change in the catchment, while
their correlations revealed the hydrological conditions under which the lake was closed. Their compositional variations are
controlled by temperature, precipitation, photosynthesis, dissolving equilibrium of the carbonate system and hydrological
condition. According to our research on inorganic C, O isotopic composition of Lake Chenghai sediments, we investigated the
environmental change of this catchment several decades ago. The results showed that Lake Chenghai has kept good hydrological
closing conditions in the past several decades, as indicated by the good correlation of inorganic C, O isotopic composition
of sediments; and that the environmental change in this catchment shows a tendency of periodical evolution on a 10−11-years scale, although the signal noise is relatively high at the bottom of the sediment core. And we also can extend C, O
isotopes, a sensitive environmental indicator, to nearly saline lake environments with a high degree of mineralization. 相似文献
15.
New Fossil Beetles of the Family Ommatidae （Coleoptera： Archostemata） from the Jehol Biota of China 总被引：2，自引：2，他引：0
TAN Jingjing REN Dong SHIH Chungkun GE Siqin 《《地质学报》英文版》2006,80(4):474-485
A new genus with one new species and five new species of genus Amblomma of fossil ommatids are described and illustrated： Euryomma tylodes gen. et sp. nov., Amblomma cyclodonta sp. nov., Amblomma miniscula sp. nov., Amblomma porrecta sp. nov., Amblomma eumeura sp. nov., and Amblomma protensa sp. nov. All of them were collected from the Upper Jurassic or Lower Cretaceous Yixian Formation of western Liaoning, China. A key to the species of Amblomma is given. The wide epipleural space shows that Euryomma may be a primitive genus in Ommatidae. Many different species of Amblomma occurred within the same sedimentary horizon in this area could be environmental changes caused by frequent volcanic activities during the deposition of the Yixian Formation. 相似文献
16.
众所周知,石炭纪-二叠纪期间冈瓦纳大陆冰盖的推进和消融在低纬度地区形成了许多高频海平面升降变化和广泛分
布的旋回沉积.最新研究表明,石炭纪-二叠纪冰室气候时期的大陆冰盖是由一系列不连续的冰期组成.因此石炭纪-二叠纪
期间既存在高频低幅的海平面变化,也发育多次大幅度海平面下降.前者在华南地区已有研究证实,后者仍需要深入研究.描
述了贵州龙吟和紫云扁平剖面早二叠世碳酸盐岩地层中古岩溶特征,包括垮塌角砾岩及相关沉积构造,分别对应早二叠世两
次冰期导致的显著海平面下降,对深入了解华南地区早二叠世古地理演化具有重要意义. 相似文献
17.
湖南古丈山体滑坡影响因子分析 总被引：1，自引：1，他引：0
为研究湖南省古丈县2016年7月17日群体滑坡的地质环境与降水诱发成因,基于GIS空间分析平台,利用古丈县1:5万地质灾害详查资料、地形地貌、公路河网、坡度坡向、地下水类型、滑坡体与岩土产状关系等空间数据,分析古丈县多种地质环境因子与滑坡事件的影响系数;采用贝叶斯后验概率分析法确定古丈滑坡降水阈值曲线(I-D曲线);基于多要素地质环境因子、临界降水条件及滑坡触发有效雨量综合分析了本次群体滑坡事件的主要成因。结果表明:出现大于当地滑坡阈值的极端降水事件(一定的滑坡降水强度、持续时间和滑坡触发有效雨量)是诱发古丈群体滑坡的主要外源动力,脆弱的岩土结构、滑坡体与岩层产状一致的滑坡类型、公路(铁路)和河网修建对山体切坡的影响、敏感的坡度区间、高风险的坡向区间等地质因子是导致古丈默戎"7·17"滑坡的地质成因,相关研究方法和结论对该地区未来地质灾害预警预报提供了方法和数据支持。 相似文献
18.
P. H. Santschi 《中国科学D辑(英文版)》2005,48(4)
Recent sediments in lakes and gulfs are a sensi-tive recorder of the information about environmentalchanges in the catchment areas during recent geologi-cal history. Precise determination of the ages of sedi-ments is the key to deciphering the environmental re-cords. The 210Pb dating technique and the markertechnique based on fallout radionuclide 137Cs havefound wide applications in sedimentation rate on atime scale of several tens to one hundred years, as wellas the varve chron… 相似文献
19.
植被降水利用效率（PUE）是评价干旱、半干旱地区植被对降水响应的重要指标。利用1982—2015年GIMMS NDVI3g NDVI数据及同期气象数据反演内蒙古荒漠草原的PUE,研究荒漠草原不同植被类型、不同地区PUE时空变化,并分析了PUE 与气候因子的相关关系。结果表明：（1）1982—2015年间荒漠草原年均PUE为0.51 gC·m-2·mm-1,PUE的分布呈现出一定的空间异质性。荒漠草原PUE极显著增大和显著增大的面积分别占草原总面积的35.88%、55.41%,荒漠草原PUE极显著减小的面积占草原总面积的8.70%,荒漠草原PUE整体呈现增大趋势。（2）荒漠草原不同植被类型PUE均值范围0.34—0.56 gC·m-2·mm-1。各种植被类型中,东方针茅草原PUE最大,镰芒针茅草原PUE最小。除了镰芒针茅草原与其他植被类型差异显著以外,其他植被类型间差异不太显著。从PUE变化看,除了东方针茅草原PUE呈现下降趋势,其他植被类型PUE都呈现增大的趋势。（3）荒漠草原PUE与降水有很强的负相关性;草地年PUE与年均气温相关性不太明显;草地年PUE与年均太阳辐射呈正相关关系。 相似文献
20.
Siqin Tong Jiquan Zhang Yuhai Bao Quan Lai Xiao Lian Na Li Yongbin Bao 《地理学报(英文版)》2018,28(5):595-610
This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index (NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series. 相似文献