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基础测绘是指建立全国统一的测绘基准和测绘系统,进行基础航空摄影,获取基础地理信息的遥感资料,测制和更新国家基本比例尺地图、影像图和数字化产品,建立、更新基础地理信息系统,是关系社会发展和国民经济的一项基础工作。基础测绘工作是提高城市管理效率、履行测绘地理信息管理职能和管理水平、增强决策水平和能力的重要手段。国民经济、国防建设和社会发展急需的基础测绘成果应当及时更新。本文从腾冲市的基础测绘工作实际情况出发,介绍了腾冲市基础测绘工作现状,对当前基础测绘工作存在的问题进行分析,并针对存在的问题提出相应的对策。 相似文献
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REN Jianguo WANG Xianbin OUYANG Ziyuan College of Marine Geosciences Ocean University of Chin Qingdao Shandong Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou Gansu Institute of Geochemistry Chinese Academy of Sciences Guiyang Guizhou 《《地质学报》英文版》2005,79(3):426-431
Gas concentrations and isotopic compositions of He and CO2 were determined on free gas samples from ten hot springs of the Rehai geothermal field, Tengchong, China. The results showed that hot-spring CO2 gas, together with He,was derived mainly from the mantle, indicating the accumulation of mantle-derived volatiles beneath the survey area. The δ^13C values of CO2, higher than those of the typical mantle-derived carbon and the isotopic composition of hot-spring-free CO2 in unequilibrium with dissolved CO2, are recognized only in the Rehai geothermal field, suggesting that there seems to be a still-degassing magmatic intrusion at depths, which provides mantle-derived volatiles to the hydrothermal system above. The accumulation of those volatiles has probably played an important role in triggering earthquakes in this region.In addition, the isotopic characteristics of He and C also indicate that the magmatic intrusion seems to have been derived from the MORB source, and could be contaminated by crustal materials during its upwelling through the continental crust. 相似文献
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