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91.
本文通过哀劳山东西坡剖面观测资料的分析,用数理统计方法建立了山区逆温的判别方程和逆温层顶高度的线性及非线性回归方程,并对影响逆温及其顶高的气象因子进行了分析。 相似文献
92.
In precise geoid determination by Stokes formula, direct and primary and secondary indirect terrain effects are applied for
removing and restoring the terrain masses. We use Helmert's second condensation method to derive the sum of these effects,
together called the total terrain effect for geoid. We develop the total terrain effect to third power of elevation H in the original Stokes formula, Earth gravity model and modified Stokes formula. It is shown that the original Stokes formula,
Earth gravity model and modified Stokes formula all theoretically experience different total terrain effects. Numerical results
indicate that the total terrain effect is very significant for moderate topographies and mountainous regions. Absolute global
mean values of 5–10 cm can be reached for harmonic expansions of the terrain to degree and order 360. In another experiment,
we conclude that the most important part of the total terrain effect is the contribution from the second power of H, while the contribution from the third power term is within 9 cm.
Received: 2 September 1996 / Accepted: 4 August 1997 相似文献
93.
94.
Nader Jalali Bahram Saghafian Farda Imanov Museyyib Museyyibov 《International Journal of Applied Earth Observation and Geoinformation》2009
Shallow karst water resources and caves may influence land surface temperatures due to cold transfer property of rocks and evaporation from buried karst. The objective of this research was to develop a method for recognition of karst areas based on evaluating the surface characteristics that manifest itself by low land surface temperature in the satellite images. Investigation of thermal ETM+ image of the study region in Iran showed that parts of carbonate rocks that bear karst water are relatively cooler compared to areas with similar terrain conditions. Relational modeling provided useful information on spatial distribution of areas that have the potential to hold karst water resources and/or caves. Further inspection of ASTER images, along with geotechnical, geophysical and geological field surveys verified the approach. Significant correlation was found between electrical resistivity and thermal band values. The method may be used as a primary exploratory tool for shallow karst water explorations in similar areas. 相似文献
95.
《International Geology Review》2012,54(6):686-713
The Brusque Metamorphic Complex (BMC) is one of the main units of the Tijucas Terrain within the Dom Feliciano Belt, located in the state of Santa Catarina in southern Brazil. In the Itapema region, the BMC is composed chiefly of metasediments, including subordinate metabasalts, meta-ultramafic rocks, and clinoamphibole schists. The metavolcanic rocks form 4 m-thick lenses interlayered with metapelites and calc-silicate schists. Based on the observed textures and the associated structural, bulk-rock geochemical, and mineral chemical data, these metamafites and ultramafites were ancient lava flows of tholeiitic basalts and ultramafic cumulates. The mineral parageneses of the metabasalts are albite?+?actinolite?+?chlorite?+?epidote?+?titanite?+?magnetite and oligoclase?+?hornblende?+?epidote?+?titanite?+?magnetite, indicating progressive transformations produced under greenschist to amphibolite facies conditions. Volcanogenic metasediments show the same geochemical patterns as the metabasalts, whereas the metamorphosed ultramafic rocks consist of cumulates generated by crystal fractionation and flow segregation. The studied rocks show similar rare-earth element (REE) patterns, characterized by clearly higher normalized contents of light REEs compared with heavy REEs, without Eu anomalies in the metabasalts and positive Eu anomalies in meta-ultramafic rocks and volcanogenic metasediments. In accordance with the trace element contents that indicate a within-plate nature, the corresponding mafic melts apparently formed in the mantle by partial fusion and were subsequently enriched with crustal components during ascent into the sialic crust. The analysed 143Nd/144Nd and 87Sr/86Sr ratios lie between 0.5123 and 0.5126 and 0.7067 and 0.7086, respectively, and are thus typical of tholeiitic basalts of the continental plateau type. Initial ?Nd(936) values and derived model ages (T DM) between 1028 and 1762 million years support a mantle source or sources, with extraction and emplacement in the Neoproterozoic. Field relations and geochemical data (including isotopic data) indicate the generation of the studied mafic and ultramafic rocks in a continental rift. In the regional geologic context, the formation of the BMC volcanic and metasedimentary units marks a period of fragmentation of the Palaeoproterozoic continental crust. This extensional event is preserved regionally in gneisses from the Santa Catarina Granulitic Complex and the Camboriú Complex. 相似文献
96.
TRMM daily precipitation data were validated compared to thirteen precipitation observation station data in Irrawaddy basin, and a calibration method of TRMM 3B42 data based on water balance concept was developed. SWAT model was used to calculate water balance, and then the TRMM data calibration ratio was inferred based on it. Average slope of sub-basin was the independent variable, and calibration ration was the dependent variable for the regression analysis. The calibration ratio of sub-basins without hydrological observation stations were calculated according to the average slope, and then the TRMM precipitation were calibrated according to the ratio in the whole basin. Results showed that TRMM annual and monthly precipitation had a highly correlation with observed data, but had a bad bias. Annual precipitation of TRMM precipitation after calibration were nearly the same as observed; monthly precipitation curve were similar with observed. Daily precipitation forecast rank was improved from medium to well, and there were 2 station forecast bad, 7 forecast well and 4 forecast medium before calibration, but 6 forecast well, 2 forecast medium and 5 forecast excellent after calibration. The results proved that TRMM data precision were highly improved over different temporal scales in Irrawaddy basin through this method, data for hydrological and water resources analysis were also provided. 相似文献
97.
98.
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????μ???????????????????????????????????????????????????????????????????????Simulink???湤????????????????????????????????????????????仯???????????????????????侫???????????????????????? 相似文献
99.
利用常规观测和地面自动站资料、NCEP1°×1°再分析资料、FY-2E卫星云图,以及武汉和荆州多普勒雷达资料,针对2011年6月17-18日湖北中东部地区一次大暴雨过程进行了天气动力学诊断和中尺度分析,结果表明:(1)暴雨是在有利的大尺度背景条件下,在特定的地域触发产生的,干冷、暖湿空气在江汉平原和鄂东剧烈交汇触发了这次大暴雨过程.(2)中尺度对流云团有3种类型:即单一云团型、合并型和急剧发展型.中尺度对流云团的大小与其生命史相关,尺度越大,生命史越长,在多个α中尺度对流云团之间的新生云团发展最为迅速,降水强度也最大.(3)呈气旋性转动的中尺度回波团和由低层较强的偏北风急流与偏南风急流辐合作用产生的中尺度复合体是此次暴雨过程雷达回波的主要表现形式;(4)地形对暴雨的强度以及落区等起到重要的作用,长江中游地区由于特定地形形成了三支明显的气流,由这三支气流组成的中尺度辐合系统促进了中尺度对流云团的形成和发展,云团F的加强和发展与地形作用密切相关. 相似文献
100.
大型走滑断裂对青藏高原地体构架的改造 总被引:15,自引:5,他引:10
青藏高原的大型走滑断裂有13条,已确定的大型韧性走滑断裂主要形成于3个时期:早古生代、印支期和新生代以来.印度/亚洲碰撞(60~50Ma)以来形成的大型韧性走滑构造位于青藏高原的南部,而且主要在喜马拉雅山链的东、西两侧,如西侧的喀喇昆仑和恰曼韧性右行走滑断裂,东侧的鲜水河-小江和哀牢山-红河韧性左行走滑断裂、崇山-澜沧江、嘉黎-高黎贡山和萨盖韧性右行走滑断裂等.主要的变形特征表现为早期具有地壳深部的韧性走滑剪切带性质,在后期抬升过程中,由韧性→韧脆性→脆性应变转化;而在青藏高原北部,表现为古韧性走滑剪切带的再活动,如阿尔金-康西瓦、东昆仑左行走滑断裂,以及新生的脆性断裂,如海源左行走滑断裂等.本文在青藏高原13条大型走滑断裂研究及综合研究的基础上,阐述不同时期的大型走滑断裂,以及它们在青藏高原地体拼合及碰撞造山中的作用,包括走滑断裂与走滑型褶皱造山、走滑断裂与挤压/转换型造山、走滑断裂与挤压盆-山体系、走滑断裂与地体相对位移和走滑断裂与地体的侧向挤出,以及走滑断裂与构造结的形成. 相似文献