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161.
分析了石河子地区位于不同海拔高度的3个观测站的降水资料,结果表明,石河子地区各地降水量分布不均,石河子年降水量最多,其次是炮台,最少是莫索湾。3站季节变化一致,均以春夏季降水量居多,约占全年63%,冬季降水量最少,约占全年的13%。降水量年际变化一致,70年代降水量偏少,80年代以后降水量偏多。出现丰水年和干旱年的降水趋势一致,且出现丰水或干旱时大面积发生的机率较大。 相似文献
162.
As shown in comparison and study of the HIRS-Tb12 data and conventional data, temperature,
humidity and vertical motion are structured differently in the Southern and Northern Hemispheres, which are well
depicted with the HIRS-Tb12 data. When high pressures rapidly decrease over the regions of South China Sea
and Arabian Sea with the HIRS-Tb12 less than 200 W/m2, monsoons will set off in the South China Sea, Arabian
Sea and Bay of Bengal, respectively. From a year of significant drought to one of significant floods, the trend of
evolution is significantly different in the downdraft areas of the subtropical highs between the two hemispheres. 相似文献
163.
164.
湘中锑(金)矿床成矿物质来源——Ⅰ.微量元素及其实验地球化学证据 总被引:9,自引:0,他引:9
为了查明湘中盆地中-低温梯(金)矿床的成矿物质来源,文章应用高分辨率ICP-MS、ICP-AES等方法对岩石与矿石进行了系统测定,并结合作者以往分析数据和实验地球化学结果,对该区盆地及周边基底地层与矿床中的微量元素分布特征及其水/岩反应效应进行了综合分析和系统研究。结果表明:Sb、Au等成矿元素在元古界基底碎屑岩中具有高的背景含量,在近似成矿条件下的水/岩反应实验中,成矿元素的淋出率达20%~90%,元古界基底碎屑岩中的金(锑、钨)矿床的周围蚀变围岩中出现明显的金负异常区。而盆地内泥盆系统地层中的高锑含量仅局限于锑矿床(化)及其蚀变围岩中;湘中锑(金)矿床中的矿石与基底碎屑岩具有相似的稀土元素球粒陨石标准化配分曲线特征,以上微量元素地球化学特征充分证明该区锑(金)矿床锑、金等成矿物质主要来源于元古界底碎屑岩。 相似文献
165.
166.
通过分析埕岛东斜坡地区东三段砂岩成岩作用特征 ,以及对该地区油气成藏系统的研究 ,总结出东三段砂岩体的成岩成藏模式。东三段上部砂体成藏于馆陶组沉积期 ,对应于早成岩 B期阶段 ,油气过早进入砂岩体 ,充填了孔隙 ,抑制了成岩作用的进行 ,使原生孔隙得以良好的保存。目前该砂体位于晚成岩 A期阶段 ,伴随形成了次生孔隙 ,并正处于第二次成藏期 相似文献
167.
168.
利用欧洲资源卫星1号和2号获取的重轨干涉测量雷达数据,首先进行干涉测量数据相关性估测,并结合干涉测量数据的振幅信息,开展新疆喀什试验区地表土地类型的识别与分类,区分和识别出裸土、盐碱地、灌丛、裸岩/戈壁、沼泽和水体 6类土地类型。最后通过对不同土地类型的后向散射特性和相关性的分析,探讨了干涉测量数据相关性与干旱-半干旱地区地表特征的关系。 相似文献
169.
Considering the existing problems of the petroleum system, this paper brings forward the concept of natural gas accumulation system and presents the dividing principles. Then detailed statistics on the accumulation factors of the 32 typical natural gas accumulation systems in China and studies on the laws controlling distribution of gas are collected. The research shows that the petroleum accumulation system is the basic unit controlling petroleum generation, migration and accumulation. Generating intensity, generating amount, accumulating efficiency and migration distance plays an important role in the distribution of natural gas. Through analysis on results of resources evaluation, discovered reserves and residual reserves, potential areas in middle-scaled petroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basins are found out to be the main basins developing and enriching gas accumulation systems. 相似文献
170.
In the Alexander von Humboldt National Park in eastern Cuba many endemic animals and plants are found in various different natural habitats, which are considered to be the most important ones for in-situ conservation in the entire Insular Caribbean. In some areas of the National Park agriculture is practised. Thus, the objective of this study was to document and analyse the different land use activities and their consequences for local resource management and conservation of biodiversity in two village areas. A particular question was: what has changed since the foundation of the National Park in 1996? As time series data for land use and aerial photographs were not available for this part of Cuba, a qualitative evaluation was carried out. For this, six different land use units were mapped in 2001 and additional information gathered for areas with special interest related to sustainable land use and resource conservation. Although most parts of the study area are influenced to various degrees by human impact, the different types of land use seem presently not to have a crucial or detrimental impact on the land resources of the Alexander von Humboldt National Park. However, exploitation of the natural resources in certain areas could be improved with different management options to reach sustainability as well as to meet the conservation objectives of the National Park. This includes reduced or abandoned agricultural use of steep slopes to reduce erosion risk as well as a facilitated regeneration of natural vegetation in many parts of the study area to be able to conserve the high valuable biodiversity of the Park. Environmental education seems to have played an important and successful role since the foundation of the Park in 1996. Since then, cropping on steep slopes as well as illegal logging and poaching could be reduced. 相似文献