环嵩山地区9000～3000aB.P.聚落演替模式及其与地形的关系     

鲁鹏  田燕 《第四纪研究》2013,33(5)

不同生产方式、生产水平、社会结构与组织形态对区域环境的选择与适应使得环嵩山地区9000～3000aB.P.聚落演替模式在时间上具有差异性.表现在裴李岗时期向仰韶时期演替过程中,为放弃原来聚落的位置,转而迁移至别的区域兴建新的聚落的“迁移型”演替模式;仰韶时期向龙山时期演替过程中,为在保留原有聚落的基础上,向周边进行扩散,寻找新的区域兴建新的聚落的“扩散型”演替模式;龙山时期向夏商时期演替过程中,为在原有聚落的基础上,面积不断扩大,规模不断扩张的“膨胀型”演替模式.这种聚落演替模式的差异性与区域环境,尤其是地形条件存在联系.生产方式的转变使得仰韶先民放弃裴李岗时期的近山台地聚落,转而迁移至更适合农业生产的山前平原兴建新的聚落.社会的稳固发展与聚落数量的增长迫使龙山先民在仰韶聚落的基础上寻求环境条件较好的区域新建聚落,以缓解人口增长带来的压力.社会形态与组织方式的变化使得夏商时期聚落在龙山时期聚落的基础上,面积不断膨胀,并最终导致聚落规模等级差异特征的形成.环嵩山地区早期聚落传承模式的差异性说明不同的社会形态与发展阶段是在一定的生产水平与特定的社会组织结构基础上对不同环境选择与适应的结果.  相似文献   

Value-by-alpha Maps: An Alternative Technique to the Cartogram     

《The Cartographic journal》2013,50(2):130-140

Abstract

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The cartogram, or value-by-area map, is a popular technique for cartographically representing social data. Such maps visually equalize a basemap before mapping a social variable by adjusting the size of each enumeration unit by a second, related variable. However, to scale the basemap units according to an equalizing variable, cartograms must distort the shape and/or topology of the original geography. Such compromises reduce the effectiveness of the visualisation for elemental and general map-reading tasks. Here we describe a new kind of representation, termed a value-by-alpha map, which visually equalizes the basemap by adjusting the alpha channel, rather than the size, of each enumeration unit. Although not without its own limitations, the value-by-alpha map is able to circumvent the compromise inherent to the cartogram form, perfectly equalizing the basemap while preserving both shape and topology.  相似文献   

基于环境一号卫星的内陆水体水质多光谱遥感监测   总被引：5，自引：0，他引：5  

朱利  姚延娟  吴传庆  张永军  陈静  王颖 《地理与地理信息科学》2010,26(2)

基于环境一号卫星多光谱数据,针对我国内陆水体开展遥感监测研究。该研究建立分地区分季节经验模型反演叶绿素a浓度,基于生物光学模型的近红外单波段方法反演悬浮物浓度,以悬浮物浓度间接反演透明度,最终基于叶绿素a和悬浮物获得基于遥感监测的内陆水体营养状态指数。以2009年6月巢湖同步观测试验验证本文的水质参数反演算法,表明叶绿素a浓度反演精度不如悬浮物浓度,两者反演精度符合水环境监测业务需求。  相似文献   

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王青平  陈光  陈超贤  赵文波 《大地测量与地球动力学》2013,33(5):49-52

??????????????????????3?????????????????????????????????????????????Χ????????????????????????????????????????????????????50 Hz????????????У???????????????????????????????????1/45?????????????????1/15??  相似文献   

A Polarized Radiative Transfer Model Based on Successive Order of Scattering     

DUAN Minzheng  Qilong MIN  LU Daren 《大气科学进展》2010,27(4):891-900

Based on Successive Order of Scattering approach, a full Vector Radiative Transfer model (SOSVRT) for vertically inhomogeneous plane-parallel media has been developed. To overcome computational burden of convergence, a simple approximation technique by truncating scattering orders with a geometry serial is used to reduce computational time. Analytical Fourier decomposition of phase matrix with three symmetry relationships and two mutual inverse operators has been implemented to further improve the computation efficiency. To improve the accuracy, a post-processing procedure is implemented to accurately interpolate the Stokes vector at arbitrary angles. Comparisons with the benchmarks for an atmosphere of randomly orientated oblate spheroids show excellent agreement for each stokes parameter (within 0.1%). SOSVRT has been tested for different atmospheric condition against RT3, which is based on doubling-adding method, the results approve that SOSVRT is accurate and much more efficient in vector radiative transfer modeling, especially for optical thin atmosphere, which is the most cases in polarized radiative transfer simulation. SOSVRT is written in fortran 90 and the code is freely accessible by contacting the author.  相似文献   

长江中下游地区春季降水的时空特征     

黄亮  赵勇  刘敏 《南京气象学院学报》2010,33(3):375-384

使用41站日降水资料和NCEP/NCAR再分析月平均资料,研究了长江中下游地区春季降水的时空特征。结果表明,过去50多年来,长江中下游地区春季的雨日、雨量呈整体下降趋势,降水强度呈东减西增的趋势;该区春季连续性降水通常以2 d降水居多,江北地区以连续性中小降水为主,而江南地区则是独立性的强降水居多。春季长江中下游地区在近50 a里呈现出干旱化趋势,其和对流层中高层气温下降关系密切,由于气温相对下降,我国东部上空高层产生气旋性环流异常,不利于降水的发生。  相似文献   

DMSP/OLS稳定夜间灯光影像的校正方法   总被引：2，自引：0，他引：2  

张梦琪  何宗宜  樊勇 《测绘通报》2017,(12):58-62,76

由于DMSP/OLS稳定夜间灯光遥感图像的不连续性和过饱和问题,该数据不具有直接可比性,使用前需进行影像校正。本文提出了一套新的稳定夜间灯光数据的校正方法,包括传感器间的依次校正、连续性校正和过饱和校正,系统校正了1992—2013年时间序列上的34期影像,并对得到的目标影像进行了目视评价、定量评价、相关评价和优势分析。校正后的图像连续性、稳定性大幅提高,与社会经济数据呈现更强烈的线性相关。同时避免了传统方法中的误差引入问题,得到了较好的校正结果。  相似文献   

An evaluation of tagging experiments on the New Zealand snapper,Chrysophrys auratus (Forster), during the period 1952 to 1963     

L. J. Paul 《新西兰海洋与淡水研究杂志》2013,47(4):455-463

Details of all known data on New Zealand snapper tagging operations to 1963 are presented and briefly analysed. Nearly 8,000 fish have been tagged, with 43 (0.5%) returned. Fishing methods have included beach‐seining, trawling, and hand‐lining; tags used have been “pig‐rings”, operculum strap tags, or Petersen discs attached by two different methods. The greatest number of returns were from line‐caught fish with Petersen discs attached through the body by nylon thread. Of the 43 fish recaptured, 33 were taken less than six miles from their tagging site, and seven had moved between 10 and 260 miles (no recapture site was given for three fish. Days at liberty ranged from one to 1,127, with a mean of 164. There were insufficient growth data for analysis.  相似文献   

Estimation of Minkowski Dimension Using Neighborhood Operations     

C. Babu Rao  Baldev Raj 《Mathematical Geology》2001,33(3):369-376

A method to estimate the Minkowski dimension using neighborhood operations is described. Its implementation using a software package IMAGER-2 on a square grid with eight connectivity is presented. It is observed that a range of successive pairs of dilations helps in arriving at the best estimate. The methodology is applied to find the Minkowski dimension of the skeleton of a stress corrosion crack.  相似文献   

附有限制条件的间接分组平差模型与公式     

高士纯 《武汉大学学报(信息科学版)》1996,(1)

针对大型测量控制网给出了两种附有限制条件的间接分组平差的函数模型。利用分组平差理论及相关最小二乘原理，推导了该两种函数模型的平差计算及精度评定公式。  相似文献