2008年东亚夏季风异常及其对江淮梅雨的影响

利用国家气象中心站点日雨量资料、NCEP再分析资料和NOAA OLR资料对2008年梅雨前后及梅雨过程中亚洲季风活动、副高及ITCZ的变化、索马里急流和南亚季风活动特征、亚太地区对流和热源分布特征等进行诊断分析,以揭示梅雨期间季风活动特征的成因及其对江淮入梅、出梅及梅雨强度的影响.结果表明,梅雨期间,季风组成成员复杂多变,无一能占绝对优势,各成员的配置均处于一个动态变化过程中,此长彼消,导致了梅雨期间雨带不稳定,是2008年度梅雨偏少的重要原因.ITCZ影响副高的变化,且超前于副高的变化,对江淮梅雨预报有重要的指示意义.6月初ITCZ突然显著增强,是副高北跳、江淮入梅的重要原因;而中旬后期ITCZ再次北抬并伴随台风登陆,直接导致了江淮出梅.6月初,索马里急流爆发,比多年平均偏早,导致阿拉伯海西南气流北涌、印度季风提前爆发,对江淮偏早入梅有一定作用.索马里急流的维持和消长对江淮梅雨的位置和强度也有一定影响.印度季风爆发及其后的变化影响印缅季风槽的北抬和其后的位置变化,并通过改变青藏高原南部和孟加拉湾热源的强度和分布,影响西南季风的东传和梅雨雨带.     

矿山地质环境治理工程对城镇发展的效应评价

为探讨矿山地质环境治理工程与相关城镇发展之间的关系,本文在阐述矿山地质环境问题及常见治理措施的基础上,依据定性及定量相结合的原则,尝试构建了治理工程产生的城镇发展效应评价模型。并以资源枯竭型城市四川省华蓥市及北京市史家营乡为例,进行了效应试评价。     

矿山地质环境问题与治理对策研究——以云南迪庆普朗铜矿一期采选工程为例

矿产资源开发在创造大量财富的同时,也对矿区生态环境产生了严重的负面影响。本文以云南迪庆有色金属有限责任公司普朗铜矿一期采选工程为例,简要分析了临近世界自然遗产"云南三江并流保护区"的普朗铜矿存在的矿山地质环境问题及影响程度,进行了矿山地质环境影响程度分区,同时提出了相应的矿山地质环境保护与恢复治理措施。     

Impact of assimilating FY-3C MWHS2 data in the RMAPS-ST forecast system on its rainfall forecasts

中层水汽初值的误差是数值预报,尤其是短期预报不确定性的重要来源.星载微波湿度计资料能很好地弥补常规资料的不足,同化微波湿度计资料对改善对流层中高层的水汽初始场精度有着重要意义.本研究基于新一代快速更新多尺度资料分析和预报系统短期数值预报系统(RMAPS-ST),选取2019年6月4-6日中国华中地区降水过程开展了 FY...     

Corona Satellite Pictures for Archaeological Studies: A Review and Application to the Lost Forbidden City of the Han–Wei Dynasties

This paper provides a state of the art of the use of declassified satellite Corona for archaeological application and deals with the use of historical archives of Corona and aerial photographs for detecting ancient hidden cultural relics that may be completely lost in the modern landscape veiled by current land uses and land covers. Geospatial analysis is adopted to identify, extract and map the subtle archaeological features and cultural landscape of the lost Han–Wei Forbidden City in the Henan Province (China). It was one of the most important cities of ancient China, served as the capital for a long period, from the Eastern Zhou (2600 BP, Zhou Dynasty) to the Eastern Han and Wei Dynasties (1900–1500 BP). Outputs from our investigations clearly provided evidence of numerous buried structures of potential archaeological interest that were compared with historical documentation and excavations carried out in the area. The geospatial analysis, applied both to aerial photograph and to Corona pictures, enabled us to discover a number of unknown sub-palaces and structures, thus providing new insights for this important archaeological area.     

Variations in chemical element compositions in different types of Holocene calcareous root tubes in the Tengger Desert,NW China,and their palaeoenvironmental significance

Calcareous root tubes (CRTs) contain abundant information about palaeoenvironmental conditions and have been used for palaeoenvironmental studies in the desert hinterlands of arid regions. However, as subclasses of CRTs, calcareous sheaths and rhizocretions are formed by different processes, and it remains unclear whether these differences produce variations in the chemical element composition. Furthermore, it remains uncertain whether variations in chemical element concentrations amongst different subclasses of the CRTs can affect palaeoenvironmental reconstructions. In this study, we collected 54 CRT samples from the Tengger Desert of northwestern China. All samples were dated by accelerator mass spectrometry (AMS) ¹⁴C dating, and the chemical element composition and concentration differences of the two CRT subclasses were determined using X‐ray fluorescence spectrometry. The CRT samples were dated to the Holocene. The calcareous sheath and rhizocretion samples contained varying concentrations of the same chemical elements. The rhizocretions had high concentrations of mobile elements (Ca, Mg and Sr) and P, whereas the calcareous sheaths had high concentrations of stable elements, including Al, Si, Ti, Zr, Rb and Ba. These differences were due to the different formation processes of the two subclasses of CRTs. Moreover, the Sr/Ca and Mg/Ca ratios in the calcareous sheaths were higher than those in the rhizocretions from the same period, but these ratio differences had little effect on palaeo‐effective moisture reconstructions at the millennial scale during the Holocene. The reconstructions were not influenced by the various CRT subclasses. The Holocene millennial‐scale moisture changes in the Tengger Desert revealed by the Sr/Ca and Mg/Ca ratios showed that there was an arid period during the Early Holocene, a humid period during the Middle Holocene and a humid to arid period during the Late Holocene.     

Nonequilibrium thermodynamic model of manganese carbonate oxidation

Manganese carbonate can be converted to many kinds of manganese oxides when it is aerated in air and oxygen.Pure manganese carbonate can be changed into Mn3O4 and γ-MnOOH,and manganese carbonate ore can be converted to MnO2 under the air-aerating and oxygen-aerating circumstances.The oxidation process of manganese carbonate is a changing process of mineral association,and is also a converting process of valence of manganese itself.Not only equilibrium stat,but also nonequilibrium state are involved in this whole process,This process is an irreversible heterogeneous complex reaction,and oberys the nonequilibrium thermodynamic model,The oxidation rate of manganese cabonate is controlled by many factors,especially nonmanganese metallic ions which play an important role in the oxidation process of manganese carbonate.     

南海北部造礁珊瑚碳同位素的时空变化及其影响因素

海南岛东岸和南岸两个礁区采集了3个活体滨珊瑚,沿珊瑚生长轴线切样进行月分辨率的氧碳同位素分析,目的是研究珊瑚碳同位素组成在季节、年际和年代际3个时间尺度上的变化与季风气候的联系.结果表明,珊瑚的δ18O值的季节性变化和年际变化在全年都基本上受表层海温的控制,基于这一相关变化可以建立同位素序列的时间标尺.在同位素的时间序列上,珊瑚δ13C值季节性变化与日照基本同步.由于日照变化主要受大气顶部太阳理论日照和云量变化的控制,而理论日照在某一地点随时间的变化是规律的,所以,云量变化是珊瑚碳同位素组成季节变化的主要因素.过去30年珊瑚δ13C值最明显的年代际变化特征是1986～1987年δ13C值的突然减小事件,这一事件与日照的变化在时间和统计特征上都有一致性,但与云量变化关系不大,可能与其他因素引起的日照变化有关.现代滨珊瑚碳同位素组成普遍存在着变小的趋势,这种年代际变化与大气CO2同位素变化一致,两者在机理上成因关系也说明,近代珊瑚碳同位素组成变小的趋势与大气CO2的变化有关.不同海区的珊瑚同位素记录对比显示,海水及其中的有机物的碳同位素组成决定着珊瑚δ13C值季节变化性在空间上的分异特征,它们在很大程度上受淡水注入量的影响;同时,日照起主要作用的光合作用也对珊瑚δ13C值的变化在空间上的分异有一定的贡献.     

“一带一路”沿线地区城市扩张和形态变化分析

尽管越来越多的人认识到“一带一路”沿线各国的城市化进程对其经济、政治和环境系统所起的重要作用,但对监测区域范围内城市扩张和形态变化的比较研究却极为有限。基于欧空局气候变化倡议项目最新发布的1992—2015年300 m分辨率的全球土地覆盖数据集、1992—2012年DMSP/OLS夜间灯光数据和2000—2015年LandScan人口数据,本文首先分析了1992—2015年“一带一路”陆域城市用地增长的空间格局和十大分区城市用地面积的动态。其次,通过分析3个时间点（1992年、2003年和2015年）上同心环内城市用地密度的时空变化,量化了“一带一路”沿线80个城市的扩张和形态变化。最后采用3种统计模型（线性、幂律和指数函数模型）来分析城市用地面积、加权灯光面积和城市人口之间的长期关系。结果显示,“一带一路”陆域城市用地面积占土地总面积的比例从1992年的0.24%上升至2015年的0.56%,并且非洲和亚洲的发展中国家是“一带一路”监测区域城市化的主要贡献者。同心环内城市用地密度从城市中心到城市边缘呈递减趋势,且城市间的空间分布完全不同。中国、欧洲、非洲、西亚、东南亚和印度6个分区人口数超过100万的城市间比较显示,除了中国城市形态变得分散,其他分区城市形态总体变得紧凑。分析结果也显示,夜间灯光信号所反映的城市经济活力和城市人口分布趋势在不同程度上影响城市空间扩张和形态变化。     

环嵩山地区史前聚落分布与环境三维可视化分析

利用GIS技术实现了环嵩山地区史前聚落分布与环境的三维可视化,制作了环嵩山地区史前聚落分布与环境三维效果图.依据三维效果图与区域环境演化特征,将环高山地区划分为河水(古黄河)、淮水与济水(古济水)3个水系区,并统计分析了3个水系区裴李岗、仰韶、龙山、夏商4个时期的遗址分布特征,以此探讨了该区域史前人类迁移的环境背景.希望能为区域聚落考古研究提供依据,并能为其他区域聚落考古三维可视化与空间分析研究提供参考与借鉴,从而推动这一研究领域的深入发展.