高密度电法在王家坡滑坡体中的应用     

庞日轩  刘铁铭  李西周  田靖  杨帅  赵峰 《陕西地质》2019,(1):79-85

通过高密度电阻率成像探测法,在王家坡滑坡体勘察中建立了滑坡体地质特征—电性特征解释模型,查明了滑坡体的空间特征,并根据实际情况,推断了新的滑坡体位置,认为现存滑坡体中部及前缘存在潜在的次级滑体,后期可能会出现滑坡前缘前移。  相似文献   

First Results of Dating Detrital Zircons from the Late Precambrian Quartzite–Schist Sequences of the Chu Block (Southern Kazakhstan)     

Kanygina  N. A.  Tretyakov  A. A.  Degtyarev  K. E.  Pang  K.-N.  Wahg  K. L.  Lee  H.-Y.  Plotkina  J. V. 《Doklady Earth Sciences》2019,489(1):1273-1276

Doklady Earth Sciences - U–Pb geochronological studies of detrital zircons from quartzite–schist sequences of the Akbastau Formation of the Chu Block (northwestern part of the...  相似文献   

Lake evolution and its implication for environmental changes in China during 1950–2000     

Zhihua Huang  Bin Xue  Shuchun Yao  Yong Pang 《地理学报(英文版)》2008,18(2):131-141

Lakes in China have undergone considerable environmental changes during the past 50 years, e.g. lake level, water area changes, as did in the past several thousands years. The enhanced human activities, such as land reclamation, application of chemical fertilizer, land use and cover, irrigation and industrialization in the catchment etc., have played an important role on the recent decades＇ changes of these lakes, although constrained to a great extent by the natural impact. Comparative study on variations of lake volume （water level, depth and area） in the eastern and western lake regions of China during 1950-2000 indicated that, lake volume in the eastern region had approximately undergone a two-stage change, i.e. a dramatic decrease from the 1950s to 1970s, and a continuous increase between the 1980s and 1990s; while, in the western region, lake volume had been decreasing nearly all the time. Further studies on some typical lakes concluded that, climatic change was a primary factor for the variations of lake volume during the past 50 years, although human activities showed important effect.  相似文献   

淮河上游全新世黄土与成壤环境变化     

李新艳  黄春长  庞奖励  何忠 《地理学报(英文版)》2009,19(1):107-117

Based on field surveys, soil samples were collected at the YPC site, Yuzhou City, Henan Province for analysis of contents of major and trace elements and their variations with XRF and comparison with the curves of magnetic susceptibility, pH value distribution, loss on ignition and particle-size distribution. It was concluded that the dust source of loess in the upper reaches of the Huaihe River Basin was different from that in the Loess Plateau. And the Holocene pedogenic environmental changes in the upper reaches of the Huaihe River Basin were revealed. Foundation: National Natural Science Foundation of China, No.40571154; No.40471119 Author: Li Xinyan (1978–), Ph.D, specialized in resource exploitation and environmental science.  相似文献   

Diversity and geographical pattern of altitudinal belts in the Hengduan Mountains in China   总被引：1，自引：0，他引：1  

Yonghui Yao  Baiping Zhang  Fang Han  Yu Pang 《山地科学学报》2010,7(2):123-132

This paper analyses the diversity and spatial pattern of the altitudinal belts in the Hengduan Mountains in China. A total of 7 types of base belts and 26 types of altitudinal belts are identified in the study region. The main altitudinal belt lines, such as forest line, the upper limit of dark coniferous forest and snow line, have similar latitudinal and longitudinal spatial patterns, namely, arched quadratic curve model with latitudes and concave quadratic curve model along longitudinal direction. These patterns can be together called as “Hyperbolic-paraboloid model”, revealing the complexity and speciality of the environment and ecology in the study region. This result further validates the hypnosis of a common quadratic model for spatial pattern of mountain altitudinal belts proposed by the authors. The spatial pattern of altitudinal belts is closely related with moisture-related exposure effect in the Hengduan Mountains. Different combinations (spectra) of altitudinal belts and different base belt types appear in windward and leeward flanks and even in the same flanks of different ranges. This is closely related with the parallel mountain ranges of the Hengduan Mountains, which, at nearly right angle with the moving direction of prevailing moisture-laden air masses from west and east, hold up the warm and humid monsoon wind from moving into the core region and result in different moisture conditions in windward and leeward flanks. However, how to quantitatively describe the moisture-related exposure effect needs further study. In addition, the data quality and data accuracy at present also affect to some extent the result of quantitative modeling and should be improved with RS/GIS in the future.  相似文献   

Heavy metal distribution and accumulation in the <Emphasis Type="Italic">Spartina alterniflora</Emphasis> from the Andong tidal flat,Hangzhou Bay,China     

Hong-Jiao Pang  Shuang-Shuang Lyu  Xue-Gang Chen  Ai-Min Jin  Pei-Sun Loh  Fei Li  Yan Jiang  Xian-Hui Yang  Kang-Kang Yan  Zhang-Hua Lou 《Environmental Earth Sciences》2017,76(17):627

In order to study the heavy metal accumulation and distribution in the roots, stems, and leaves of Spartina alterniflora, we collected S. alterniflora samples and the associated sediments along three transects at the Andong tidal flat, Hangzhou Bay. Co, Ni, Cd, Pb, Cu, and Zn were mainly accumulated in the aerial parts (stems and leaves) of the plants, and their distributions depended on their mobility and their roles during the metabolism processes of S. alterniflora. The concentrations of Cu, Zn, Cd, Hg, and Pb were significantly enhanced with the increasing of heavy metal concentrations in the sediments, while those of Co and Ni remained relatively constant. Bioaccumulation factors results showed that the serious heavy metal contamination in the sediments from the transect A may overwhelm the accumulation capability of the plants. In addition, the physicochemical properties of the sediments and the pore water therein also play a role in the heavy metal concentrations and accumulations in the plants, because they can influence the behaviors and bioavailabilities of heavy metals during nutrition and bioaccumulation processes of the plants. The sediments with vegetation did not show significantly decreased heavy metal concentration with respect to the unvegetated sediments, although the plants did absorb heavy metals from the sediments. Principal component analysis and correlation analyses indicated that Co–Ni, Cu–Cd–Hg behaved coherently during accumulation, which may be ascribed to their similar accumulation mechanisms. This work provided essential information on the heavy metal accumulation by plants in a tidal flat, which will be useful for the environmental control through phytoremediation at estuaries.  相似文献   

Structure analyses of the explosive extratropical cyclone: A case study over the Northwestern Pacific in March 2007     

Shuai Wang  Gang Fu  Huaji Pang 《中国海洋大学学报(英文版)》2017,16(6):933-944

The synoptic situation and mesoscale structure of an explosive extratropical cyclone over the Northwestern Pacific in March 2007 are investigated through weather station observations and data reanalysis. The cyclone is located beneath the poleward side of the exit of a 200 hPa jet, which is a strong divergent region aloft. At mid-level, the cyclone lies on the downstream side of a well-developed trough, where a strong ascending motion frequently occurs. Cross-section analyses with weather station data show that the cyclone has a warm and moist core. A ‘nose' of the cold front, which is characterized by a low-level protruding structure in the equivalent potential temperature field, forms when the cyclone moves offshore. This ‘nose' structure is hypothesized to have been caused by the heating effect of the Kuroshio Current. Two low-level jet streams are also identified on the western and eastern sides of the cold front. The western jet conveys cold and dry air at 800–900 hPa. The wind in the northern part is northeasterly, and the wind in the southern part is northwesterly. By contrast, the eastern jet carries warm and moist air into the cyclone system, ascending northward from 900 hPa to 600–700 hPa. The southern part is dominated by the southerly wind, and the wind in the northern part is southwesterly. The eastern and western jets significantly increase the air temperature and moisture contrast in the vicinity of the cold front. This increase could play an important role in improving the rapid cyclogenesis process.  相似文献   

汉江上游郧县庹家湾剖面光释光测年及意义     

张文桐  庞奖励  黄春长  周亚利  查小春  崔天宇  王海燕  杨丹 《中国沙漠》2017,37(5):885-892

在野外考察基础上选择湖北郧县庹家湾剖面为研究对象。在对磁化率和粒度进行分析的同时,用单片再生剂量法进行了光释光测年（OSL）地层断代。OSL测年数据显示：剖面样品年龄处在55.11~13.57 ka BP,且与地层深度呈现出良好的对应关系,此剖面为黄土风化堆积形成。黏粒含量、黏粒/粉砂值以及磁化率值等气候替代性指标数值在马兰黄土层228~260 cm和294~370 cm深度明显高于典型马兰黄土（L₁）,具有明显的成壤特征,通过OSL测年数据判断时间为27.26~21.59 ka BP,说明在晚更新世时期气候并非持续稳定的寒冷干旱,而是具有一定的波动,在此期间气候相对温暖湿润,而且此次气候事件在黄土高原地区其他沉积记录中也有良好记录。  相似文献   

基于气候统计特征的雷达回波质控方法     

王国荣  平凡  仰美霖  庞琦烨 《气象科技》2019,47(1):19-28

利用北京南郊S波段雷达2011—2016年的观测资料,从雷达气候统计的角度,利用不同强度回波发生频率的统计特征及其空间分布特征,对雷达地物杂波和波束遮挡的识别与订正方法进行研究。结果表明:①利用雷达回波出现频率特征,可以很好地识别雷达近中心地物杂波和受地形高度影响的地物杂波特征;同时还可以直观地识别出雷达波束遮挡区域以及遮挡程度。北京南郊雷达地物杂波主要分布在近雷达中心和北京西部、西北部的山前地区,地物杂波主要集中在0.5°仰角和1.5°仰角层上。雷达波束遮挡主要集中在由高大建筑引起遮挡的东南方位向和由于地形引起波束遮挡的西西北方位向,波束遮挡主要集中在0.5°仰角层。②采用局部可变区域平均垂直廓线方法利用高仰角回波订正低仰角回波,能有效订正地物杂波,并保留回波的局部特征。对于波束遮挡区域的回波填补,也能够较好地保持上下层仰角回波之间的连续性,同时兼顾了回波不均性分布等特性。③基于雷达气候特征进行地物杂波识别和波束遮挡识别,无需依照先验知识,相比于传统方法能更好地反映本地雷达回波真实情况,且具有方法简单、可快速复用、本地适用性强等优点。  相似文献   

辽宁省国土资源沙盘模型制作及特点   总被引：2，自引：1，他引：1  

张衍明  庞群 《现代测绘》2003,26(3):43-44

本文以辽宁省国土资源沙盘模型为例,详细介绍了现代沙盘模型的制作方法及特点。  相似文献