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551.
Hydrological processes related to soil moisture play an important role in determining regional and global climate. In this study, using a state-of-art Community Land Model (CLM) developed by the National Center for Atmospheric Research (NCAR), we simulated soil moisture in East Asia and its possible response to global warming through a long off-line experiment under 0.5° (longitude) × 0.5° (latitude) resolution and real atmospheric forcing of the National Center for Environmental Protection/ Department of Energy (NCEP/DOE) reanalysis during 1979 through 2003. The 25-year simulation is examined and compared with limited observations. The results can be summarized as follows: (1) Soil moisture takes time in response to the atmospheric forcing. The equilibration time depends on the depth of the soil and is as much as 20 years in deep layers (>1.5 m); (2) In comparison with observations, the CLM reasonably reproduces the seasonal and inter-annual variability, spatial structure, and vertical pattern of soil moisture in East Asia; (3) The soil tends to be drier in the past 25 years in northeastern Asia-including northern China north of 30°N-while wetter in the southern China and the Tibetan Plateau, especially in summer. Our analysis shows that the regional drying is attributed to increase of the land-surface evaporation induced by global warming. 相似文献
552.
Eco-geographic regional system is formed by division or combination of natural features based on geographic relativity and comparison of major ecosystem factors (including biological and non-biological) and geographic zonality. In previous studies, soil types were often taken as a basis for soil regionalization. However, the quantitative characteristics of soil indicators are fitter than the qualitative ones of soil types for modern regionalization researches. Based on the second China’s national soil survey data and the provincial soil resource information, by principal analysis and discriminant analysis, this paper discusses the appropriate soil indicators as the complement of eco-geographic region indicator systems and the relationships between these soil indicators and soil types in regionalization. The results show that five indicators are used in eco-geographic zonality in mid-temperate zone of eastern China which are organic matter content, cation exchange capacity, pH, clay content and bulk density in topsoils. With a regression-kriging approach, the maps of soil indicators in mid-temperate zone of eastern China are compiled with a resolution of 1 km in every grid and the indicative meanings of these soil indicators are discussed. By cluster analysis it is proved that these soil indicators are better than the soil types and soil regionalization in delineating eco-geographic regions. 相似文献
553.
Ying Li Jianguo Du Fukuan Wang Xiaocheng Zhou Xiaodong Pan Ruqing Wei Institute of Earthquake Science China Earthquake Administration Beijing China Inner Mongolia Corporation Ltd.of Geologic Engineering Hohhot China Earthquake Administration of Jilin Province Changchun China Liaocheng Seismology Hydro-chemistry Test Station Liaocheng China 《地震学报(英文版)》2009,(1):93-100
The geochemical backgrounds and origins of soil gases in the Yanhuai basin are discussed based on the regional seismogeological data and concentrations of Rn,Hg,CO2,H2,He and CH4 in soil gas measured at 422 investigating sites in field during September to October 2007.The geochemical background values of Rn,Hg,CO2,H2,He and CH4 are(8105.8±5937.4) Bq/m3,(9.7±5.8) ng/m3,(395.9±35.3)×10-6,(4.0±2.3)×10-6,(15.9±10.4)×10-6 and(12.7±8.1)×10-6,respectively.The geochemical backgrounds of the soil gases are higher in... 相似文献
554.
With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine carbonate formation in superposition-basin becomes a hot topic in the field of petroleum geology. Based on the structure inversion, numerical simulation, and geochemical research, we show at least two intervals of fluid transfer in Puguang paleo-oil reservoir, one in the forepart of late Indo-Ch... 相似文献
555.
四川宣汉地区二叠系茅口组和吴家坪组的硅岩,主要以结核状、条带状和团块状产出。根据硅岩的岩石学及地球化学特征,对其成因进行了系统研究。野外观察硅岩形态多样,与围岩呈缝合线状接触,在剖面上受一定层位控制,团块状硅岩中含石灰岩斑块等。显微镜下观察,硅岩中见方解石残余结构及白云石菱形假晶等。野外观察和显微镜下观察表明这些硅岩应为交代作用形成。常量元素分析表明硅岩以SiO2为主(69.61%~99.21%),其他化学成分含量较低(0.01%~16.07%),Fe/Ti、(Fe+Mn)/Ti及Al/(Al+Fe+Mn)值反映了硅岩的形成与热水活动有关,样品点在Al-Fe-Mn三角图中的投影位于富铁端;微量元素Co/Ni、V、Ti/V、Th/U和Rb/Sr值都较低,样品点在(Cu+Co+Ni)-Fe-Mn三角图中的投影也位于富铁端;硅岩中稀土元素总量低(低于10×10-6),Ce明显负异常,Eu弱负异常,LREE/HREE值低,Eu/Eu*值相对较高。上述特征表明研究区硅岩在形成过程中有热水物质参与沉积,在成岩过程中通过SiO2交代作用形成。 相似文献
556.
557.
青藏高原近30年气候变化趋势 总被引:209,自引:17,他引:192
以1971~2000年青藏高原77个气象台站的观测数据 (最低、最高气温,日照时数,相对湿度,风速和降水量) 为基础,应用1998年FAO推荐的Penman-Monteith模型,并根据我国实际状况对其辐射项进行修正,模拟了青藏高原1971~2000年的最大可能蒸散,并由Vyshotskii模型转换为干燥度,力求说明近30年青藏高原的气候变化趋势,以及干湿状况的空间分布。应用线性回归法计算变化趋势,并用Mann-Kendall方法进行趋势检验。结果表明:青藏高原近30年气候变化的总体特征是气温呈上升趋势,降水呈增加趋势,最大可能蒸散呈降低趋势,大多数地区的干湿状况有由干向湿发展的趋势。气候因子与地表干湿状况间并不是线性关系,存在很大的不确定性。 相似文献
558.
上海地区强对流天气短时预报系统 总被引:18,自引:2,他引:16
以强对流天气的发生、发展规律为依据,从中尺度数值预报模式输出结果、Doppler天气雷达、静止气象卫星、MICAPS系统和自动雨量站网等获取大气运动的各种尺度动力条件、水汽条件、大气稳定度和触发机制,各种天气实况等动态变化资料,结合预报员经验,建立了“上海地区强对流天气短时预报系统”(以下简称“预报系统”),预报系统产品包括强对流天气的形势分析、0~12h展望预报、0~3h滚动预报及警报。预报系统 相似文献
559.
基于成矿系统动力学研究进展的综合分析, 认为构造体制转换与流体多层循环成矿动力学研究是地球科学跨世纪的重要前沿领域之一, 进而提出这一领域的研究主题和关键问题、研究思路及方法, 阐释其重要意义, 指出构造体制转换与流体多层循环成矿动力学研究以构造演化、流体活动及区域地球化学和地球物理不均一性为基础, 通过变形-流动高温高压实验及计算机数值模拟再现成矿作用过程和机理, 解析构造体制转换与流体多层循环成矿动力学特征, 揭示成矿界面时-空演化规律, 建立成矿系统物质和能量交换-反馈耦合成矿的定量模型.这是深化矿床成因认识的重要基础和实现科学找矿的有效途径, 对地球系统科学和大陆动力学的研究也具有重要意义. 相似文献
560.