城市地理信息系统软件工具及其应用

本文首先在分析城市地理信息系统(UGIS)应用任务、专业内容和技术要求的基础上,提出了我国UGIS的研究内容及其软件发展的工具模式;接着,以GRAMS软件为例,论述了UGIS软件工具的总体结构、主要功能和技术特点;最后,还结合一些具体的应用系统,如中国城市信息系统、城市水资源信息系统以及城市环境信息系统等,介绍了UGIS软件工具的不同使用方式以及给人们带来的实际好处。     

基于GIS和USLE的东圳库区土壤侵蚀量预测研究

运用GIS、遥感技术与USLE模型相结合预测东圳库区流域土壤侵蚀量,利用GIS平台建立东圳库区基础地理数据库,以10×10m为栅格单元对库区进行离散化,在GIS空间分析功能支持下,结合USLE土壤侵蚀预测模型,根据合适的USLE因子算法生成栅格图层,通过图层运算,预测了东圳库区土壤侵蚀量,进而标识库区土壤侵蚀严重区域,为库区非点源污染控制及水土流失治理提供定量依据,并通过建立实用的泥沙输移比模型结合水文监测数据,对预测结果进行验证。根据USLE方程,采用改进后的SDR方程,预测的渡里流域年输沙量与流域实际监测得到的年输沙量仅相差14.08%,说明本文采用USLE方程模拟流域土壤侵蚀结果可信,可定量评价、拟定水土保持措施方案。     

南海北部中更新世晚期以来古海岸变迁及其地质意义

本文在研究南海北部陆架区ZQ2和ZQ4钻孔资料的基础上，对该区单道地震资料进行地震层序划分、地震-沉积相解释分析。根据钻孔地层、地震反射和海底地貌特征，对中更新世晚期、末次盛冰期以及冰后期这三个时期的古海岸位置进行了分析，并探讨了该区中更新世晚期以来的古海岸变迁，对进一步指导该区的第四纪环境研究具有重大意义。     

Study of small ions concentration in the air above Athens, Greece

Measurements of positive and negative small atmospheric ion concentrations have been made regularly since 1968 at the National Observatory of Athens (NOA). In this paper the 17-year period 1968–1984 is summarized. The diurnal and annual variations are examined, and Fourier analysis is also used for the study of the diurnal variation. The concentrations of small ions follow a double diurnal course. The maxima occur near 3–5 h and 13–16 h local time (LT = GMT + 2 h). The minima are observed at 6–8 h and 21–23 h. The annual course of small ions presents maximum concentration values around the summer season. The mean of the small ion concentration (SIC) for the 17-year period (1968–1984) is n₊ = 188.8 ions/cm³ for positive ions and n₋ = 151.1 ions/cm³ for negative ions. Their ratio is equal to 1.25. The year-to-year variation of SIC for the examined period shows a negative trend. The results from multiple regression analysis show that wind speed and SIC are positively correlated, while relative humidity, smoke and sulphur dioxide are negatively correlated.     

知识经济时代我国测绘产业面临的挑战与对策

我国正处在由传统经济向知识经济转变的重要时期,信息化、知识化已成为当今世界经济发展的主要方向。我国测绘产业面临知识经济的挑战和机遇,应当加强人才资源、信息资源的开发和利用,加快数字化、网络化、集成化、智能化建设,逐步实现由传统测绘产业向地理信息产业的转变,为我国国民经济信息化建设提供坚实的基础。     

区域构造分析与GIS技术在湘中地区锑矿成矿预测中的应用

本文从区域构造分析和ＧＩＳ技术两个方面,对湘中地区锑矿找矿前景进行了概略评价,指出了找矿目标与找矿远景地段。     

Comparative analysis of sediment yield estimations using different empirical soil erosion models

The study aims to evaluate the performance of different empirical soil erosion models (EPM, USLE, Koutsoyiannis and Tarla, RUSLE) in mountainous Mediterranean-type catchments. The study area comprises the Arachthos, Kalamas, Upper Acheloos and Venetikos river basins, located in northwestern Greece. The methodology followed includes both qualitative and quantitative analyses. The former refers to the specific attributes of the models and the latter to the estimated sediment yield results. The results were initially validated against observed sediment yield values. The ambiguous reliability of such measurements led to their replacement by simulated ones, estimated using the sediment rating curve methodology. In the latter analysis, the models performed better, with more accurate results. Overall, the RUSLE corresponded best to such basins. Finally, the performance of seven empirical equations (Syvitski, Avendano Salas et al., Dendy and Bolton, Lu et al., Webb and Griffiths, Zarris et al.) was assessed, yielding relatively poor results.     

海上风电场区位分布的动态演进和影响因素研究

为应对能源安全和气候变化,培育新兴产业,我国大力发展海上风电产业。经过十余年发展,海上风电累计装机总量已跃居全球首位,但在这一过程中,风电场的区位分布表现出显著的时空异质性,即随着时间推移,其经历一个由江苏到福建、广东、山东等地动态演化的过程,研究不同阶段影响区位分布的主导因素及其变化,对政府制定有效政策以促进产业发展具有重要意义。根据国家发布的政策文件以及中国风能协会等公布的数据,本文划分了海上风电发展阶段,采用动态偏离-份额拓展模型来测度产业转移以揭示区位分布的演进;进一步将模糊集定性比较分析法与地理探测器模型结合,从动态的角度分析了产业发展各阶段区位分布的主导因素及其变化,并剖析了增长突出省区市的发展路径及其差异化。研究表明,发展初期,海上风电场区位分布受政府扶持力度和自然因素的影响较多,随着产业发展及技术进步,创新环境与专业人才逐渐成为关键因素,典型的发展路径有政策驱动型、水域-政策驱动型、风能驱动型、创新-知识型、知识-政策驱动型等。进一步加快人才培养、完善产业链条、优化扶持方式应成为推动产业健康持续发展的努力方向。     

Late Holocene Moisture Changes in the Core Area of Arid Central Asia Reflected by Rock Magnetic Records of Glacier Lake Kalakuli Sediments in the Westernmost Tibetan Plateau and their Influences on the Evolution of Ancient Silk Road

The evolution of Ancient Silk Road(ASR) was deeply influenced by late Holocene moisture changes in Arid Central Asia(ACA). Nevertheless, controversies in Holocene moisture change pattern of ACA and poorly–constrained age models of related studies have made the discussion about late Holocene moisture changes in ACA and their influences on the evolution of ASR difficult. Recently, a high–resolution age model during the late Holocene was established for Kalakuli Lake, a small glacier lake located in the core area of ACA. A thorough rock magnetic investigation was carried out on Kalakuli Lake sediments based on this age model. The magnetic mineral assemblage of Kalakuli Lake sediments is still dominated by primary magnetite despite minor diagenetic effects. Comparisons of rock magnetic records to parameters previously used as indicator of glacier fluctuations suggest that clastic input to Kalakuli Lake was high(low) and magnetic grain size is relatively larger(smaller), when glaciers on Muztagh Ata advanced(retreated). The ARM/SIRM ratio, a magnetic grain size proxy, is directly related to lake hydrodynamics, which are ultimately controlled by glacier fluctuations on Muztagh Ata as the result of regional moisture changes. Late Holocene moisture changes indicated by the ARM/SIRM ratio are consistent with cool/wet and warm/dry oscillations indicated by the unweighted average of biomarker hydrogen isotopic data of the C_(26) and C_(28) n–alkanoic acids in a previous study about Kalakuli Lake, most moisture change records of the core area of ACA and winter insolation of the Northern Hemisphere, but opposite to Asian monsoon evolution. Given Asian monsoon and the westerlies are mutually inhibited, we propose that late Holocene moisture changes in the core area of ACA were controlled by the intensity of Asian monsoon versus the westerlies under the governance of solar insolation. Generally increased moisture since the late Holocene indicated by the ARM/SIRM ratio favored cultural exchange and integration between the western and the eastern Eurasia, which paved the way for the formation of ASR. Coincidence between significant increase in moisture at ～200 BC suggested by the ARM/SIRM ratio and the formation of ASR indicates moisture as an important factor that facilitated the formation of ASR. The onsets of three prosperity periods of ASR in the history generally correspond to periods when moisture was relatively high, nevertheless, stagnant periods of ASR do not coincide with periods when moisture was relatively low in the core area of ACA. Disorganized correlations between stagnant periods of ASR and moisture changes in the core area of ACA suggest that moisture is not the decisive factor influencing the evolution of ASR.     

Ground subsidence,Quaternary faults and vulnerability of utilities and transportation networks in Thessaly,Greece

Ground fissures and subsidence have caused extensive damage in structures and the utility networks (roads, railroad line, Larisa NATO airport, telecommunication network) in the plain of Thessaly, central Greece, in the last 20 years. The fact that these fissures are parallel to Quaternary faults controlling the structural evolution of the Thessaly basin, marked by intense recent seismic activity, led some scientists to regard them as manifestation of tectonic creep, even premonitory phenomena of major future seismic events. A careful study of the geometric characteristics and of the kinematics of these ground fissures, however, revealed that they only reflect shear failure of the ground due to compaction of loose sediments following significant decline of the groundwater level due to over-pumping; i.e. a geotechnical and not a tectonic process. Furthermore, theoretical considerations and modeling predict surface fissuring along zones of anomalous basement, normal-fault controlled topography. This explains the correlation between ground fissures and active Quaternary normal faults.