长江和黄河入海沉积物不同粒级中长石/石英比值及化学风化程度评价   总被引：2，自引：0，他引：2  

杨作升  赵晓辉  乔淑卿  李云海  范德江 《中国海洋大学学报(自然科学版)》2008,38(2):244-250

长石/石英(F/Q)比值是评估碎屑沉积物化学风化强度的传统指标.在长江大通站和黄河利津站及相应河口区各取9个沉积物样品,将其<125 μm的部分按1间隔分离成7组不同的粒级,用X-ray衍射法半定量分析测定了全样和不同粒级沉积物中石英和长石的相对含量,计算了长石/石英(F/Q)、钾长石/石英(Fk/Q)、斜长石/石英(Fp/Q)比值,据此评估了长江和黄河入海沉积物化学风化强度随粒级的变化.结果显示取自黄河样品的F/Q,Fk/Q和Fp/Q比值在总体上显著高于长江样品,与长江流域的化学风化强度高于黄河的结论一致,可以作为流域沉积物化学风化强度替代指标.长江样品的F/Q,Fk/Q和Fp/Q比值随粒级变细持续变低,黄河样品则呈波动式下降.黄河样品的F/Q高出长江样品的部分主要发生在＜32 μm的细粒级,在粗粒级区间差别很小,当沉积物粒级下降到一定区间后F/Q差异出现快速增加,显示长江流域沉积物的风化程度高于黄河主要发生在较细粒级.上述比值在黄河样品的2～4 μm粒级中高出长江样品3～5倍,是凸显两河化学风化强度差别的敏感粒级,也可以作为两河物源示踪的指标.  相似文献   

江苏省环太湖地区土地利用结构演变与驱动力分析   总被引：6，自引：0，他引：6  

李闽  孙在宏  杨素静  乔伟峰 《地球信息科学学报》2008,10(2):136-141

本文以江苏省环太湖地区为研究区域,以1996～2007年快速发展时期为研究时段,对这一特定时空的土地利用结构变化及其驱动机制进行研究。文章以大量数据为基础,分析了区域内土地利用结构动态度、信息熵和均衡度。1996年以来,江苏省环太湖地区用地结构调整即以趋向均衡的速度逐渐变缓。从2004年开始,江苏省环太湖地区用地结构趋向合理、均衡化发展。文章揭示了土地利用结构与经济发展驱动因素、农业集约化因素、城市化因素、人口因素、政策因素这五个因素有关。  相似文献   

《中国改革开放30年地图集》选题研究与创意设计     

王桂芝  乔俊军  王茜  周文 《测绘与空间地理信息》2009,32(4):179-183

紧紧围绕"纪念改革开放30年"这一主题,对展示内容的设计和地图表现方法进行了深入的研究与实践,总结出一套行之有效的设计思想,可供类似工作参考.  相似文献   

重力异常辅助惯性导航中匹配区提取方法     

马旭东  闫利  乔永杰 《测绘科学技术学报》2009,26(6)

由于重力场中的重力异常数据是以格网的形式表示的,它与地形的DEM在数据结构上有一定的相似性.因此可借鉴一些数字地形分析的方法,提取重力场的特征区域(匹配区)用于辅助惯性导航.首先,对重力场进行特征提取,通过对特征的比较分析选取其中的某些因子作为重力场特征因子;然后,利用等值线方法对重力场特征数据进行区域分割,提取栅格特征数据区域的矢量边缘,并对这些矢量表示的区域进行聚类处理;最后,利用凸壳算法提取这些区域的凸壳范围线,获得重力异常变化比较显著的区域(匹配区).从而为重力匹配辅助导航提供了必要的参考数据.  相似文献   

基于地理探测器的喀斯特不同地貌形态类型区土壤侵蚀定量归因（英文）     

王欢  高江波  侯文娟 《地理学报(英文版)》2019,(2):271-286

The formation mechanism and influencing factors identification of soil erosion are the core and frontier issues of current research. However, studies on the multi-factor synthesis are still relatively lacked. In this study, the simulation of soil erosion and its quantitative attribution analysis have been conducted in different geomorphological types in a typical karst basin based on the RUSLE model and the geodetector method. The influencing factors, such as land use type, slope, rainfall, elevation, lithology and vegetation cover, have been taken into consideration. Results show that the strength of association between the six influencing factors and soil erosion was notably different in diverse geomorphological types. Land use type and slope were the dominant factors of soil erosion in the Sancha River Basin, especially for land use type whose power of determinant(q value) for soil erosion was much higher than other factors. The q value of slope declined with the increase of relief in mountainous areas, namely it was ranked as follows: middle elevation hill> small relief mountain> middle relief mountain. Multi-factors interactions were proven to significantly strengthen soil erosion, particularly for the combination of land use type with slope, which can explain 70% of soil erosion distribution. It can be found that soil erosion in the same land use type with different slopes(such as dry land with slopes of 5° and above 25°) or in the diverse land use types with the same slope(such as dry land and forest with a slope of 5°), varied much. These indicate that prohibiting steep slope cultivation and Grain for Green Project are reasonable measures to control soil erosion in karst areas. Based on statistics of soil erosion difference between diverse stratifications of each influencing factor, results of risk detector suggest that the amount of stratification combinations with significant difference accounted for 55% at least in small relief mountain and middle relief mountainous areas. Therefore, the spatial heterogeneity of soil erosion and its influencing factors in different geomorphological types should be investigated to control karst soil loss more effectively.  相似文献   

The Belt and Road: Geographical pattern and regional risks   总被引：1，自引：1，他引：0  

Wu  Shaohong  Liu  Lulu  Liu  Yanhua  Gao  Jiangbo  Dai  Erfu  Feng  Aiqing  Wang  Wentao 《地理学报(英文版)》2019,29(4):483-495

Journal of Geographical Sciences - Building the Belt and Road is initiatives of China to promote win-win international cooperation in the new era, aiming at green, health, intellect and peace and...  相似文献   

Evaluation of the integrated multi-satellite retrievals for global precipitation measurement over the Tibetan Plateau     

MA Lu  ZHAO Lin  TIAN Li-ming  YUAN Li-ming  XIAO Yao  ZHANG Le-le  ZOU De-fu  QIAO Yong-ping 《山地科学学报》2019,(7)

The availability of high-resolution satellite precipitation measurement products provides an opportunity to monitor precipitation over large and complex terrain and thus accurately evaluate the climatic, hydrological and ecological conditions in those regions. The Global Precipitation Measurement(GPM) mission is an important new program designed for global satellite precipitation estimation, but little information has been reported on the applicability of the GPM’s products for the Tibetan Plateau(TP). The object of this study is to evaluate the accuracy of the Integrated Multi-Satellite Retrievals for GPM(IMERG) Final Run product under different terrain and climate conditions over the TP by using 78 ground gauges from April 2014 to December 2017. The results showed the following:(1) the 3-year average daily precipitation estimation in the IMERG agrees well with the rain gauge observations(R~2=0.58, P0.01), and IMERG also has a considerable ability to detect precipitation, as indicated by a high probability of detection(78%-98%) and critical success index(65%-85%);(2) IMERG performed better at altitudes from 3000 m to 4000 m with a small relative bias(RB) of 6.4%. Precipitation change was not significantly affected by local relief;(3) the climate system of the TP was divided into four climate groups with a total of 12 climate types based on the K?ppen climate classification system, and IMERG performed well in all climate types with the exception of the arid-desert-cold climate(Bwk) type. Furthermore, although IMERG showed the potential to detect snowfall, it still exhibits deficiencies in identifying light and moderate snow. These results indicate that IMERG could provide more accurate precipitation data if its retrieval algorithm was improved for complex terrain and arid regions.  相似文献   

新世纪版《国家普通地图集》的内容策划与结构设计     

王桂芝  王东华  乔俊军  朱秀丽 《地理信息世界》2019,(2):67-72

新世纪版《国家普通地图集》是国家科技基础性工作专项《国家大地图集》系列编研项目之一,它以相对平衡的程度详细表示了水系、地貌、居民地、交通、境界、土质植被等基础地理要素的空间分布。为了适应生态文明建设和新型城镇化发展的要求,增设了地表覆盖图组和城市图组,构建了普通地图集的新型结构模式,本文主要对地图集的编研理论与内容策划、选题原则与顾及因素、结构设计与图幅编排进行了探讨和研究。  相似文献   

Temporal-Spatial Variation of Surface Suspended Matter and Controlling Factors in the Inner Shelf of the East China Sea in Winter     

MIN Jianxiong  LI Guangxue  DING Dong  QIAO Lulu  MA Yanyan  YANG Gang  ZHANG Yaqi  ZHANG Lei  LI Shuhao 《中国海洋大学学报(英文版)》2019,(1):9-19

Based on the observed surface suspended matter in the East China Sea in February 2007 and June 2015, an empirical model was established using L1 b's band 4 data to retrieve surface suspended matter from the Moderate Resolution Imagine Spectroradiometer Terra imagery. The squared correlation coefficient is 0.8358, and the root mean square error is 0.4285 mg L-1. The model reflects the distribution characteristics of surface suspended matter in the inner shelf of the East China Sea. In this paper, the satellite images of the study area were retrieved in January from 2001 to 2015, and the monthly distribution of surface suspended matter were obtained. The inter-annual distribution of the study area is similar, and the concentration of surface suspended matter is higher near the shore than offshore. A large amount of surface suspended matter is transported southeast under the influence of Zhejiang and Fujian coastal current and Taiwan warm current. Only a small amount of surface suspension can reach the Kuroshio area. The surface suspended matter concentration changes obviously near the estuary because of the effect of differences in the flux of the Yangtze River. Meanwhile, winter monsoon, temperature front, El Ni?o events, and other factors affect the distribution of surface suspended matter in 100 m isobath to coastal water but minimally influence the distribution in 100 m isobath to deep sea.  相似文献   

2003-2017年北京市地表热力景观时空分异特征及演变规律   总被引：9，自引：3，他引：6  

乔治  黄宁钰  徐新良  孙宗耀  吴晨  杨俊 《地理学报》2019,74(3):475-489

利用2003-2017年MODIS地表温度数据,分别从数量、形状和结构角度揭示北京市不同季相和昼夜间地表热力景观时空分异特征,并进一步通过热力等级变化图谱及质心迁移轨迹揭示城市热力景观空间演变规律,探究热力景观等级转换生态过程。结论如下：① 城市地表热力景观季节和昼夜空间特征差异显著;② 中温区在城市热环境中占主导地位。白天中温区是最不稳定的热力景观等级;夜间次低温区和次高温区不稳定性增加;③ 地表热力景观等级变化以稳定型占主,反复变化型和前期变化型次之。地表热力景观等级通常呈现逐级递增或递减规律,山区呈现逐级降温趋势,北部城郊—山地交错地带表现出次低温和中温的反复转向,南部地区有一定的升温趋势;④ 2003-2017年高温区面积增大且质心向城市中心集中,低温区质心向城市外围扩散。生态涵养发展区对北京市地表热力景观质心迁移贡献率最高。热力景观时空分异特征及演变规律可为有效缓解城市热岛效应提供管理决策支持。  相似文献