Hydrological and climatological glaciers observation 20 years on Tanggula Pass of Tibetan Plateau: its significance and contribution     

TanDong Yao  YinSheng Zhang  JianChen Pu  LiDe Tian  Yutaka. Aget  T. Ohata 《寒旱区科学》2011,3(3):0187-0196

Two decades have passed since China and Japan jointly launched hydrological & climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been either restructured or renamed, their work, between 1989 and 1993, was ground-breaking and remains significant even to this day. Some observation sites established at that time are still utilized for large-scaled projects sponsored by GAME/Tibet, NSFC (Natural Science Foundation of China) and the Major State Basic Research Development Program of China (973 Program). Recently, a glacier monitoring system has been established on the cap of Dongkemadi Glacier, and is expected to make further contributions to research on the change of the cryospheric and climatic environment in the area.  相似文献   

太原酸雨特征分析   总被引：7，自引：0，他引：7       下载免费PDF全文

徐可文  任璞  王军平 《山西气象》2005,(4):11-13

本文利用太原市的1993年-2003年的酸雨观测资料，计算了近十年的酸雨率、酸雨PH年平均值等反应酸雨强度的参数，分析了酸雨强度的变化；统计并绘制了酸雨季节分布图，描述酸雨特征并分析了造成酸雨降水的原因。结果表明太原市近十年来酸雨率呈曲折式上升趋势，酸雨强度有小幅度的季节变化，特别是近几年酸雨率及强度呈直线上升趋势，酸雨对太原市将造成一定的危害。  相似文献   

Radio loudness of high-redshift (z≥3) quasars from the Sloan Digital Sky Survey     

Xingting Pu 《Astrophysics and Space Science》2012,337(1):331-334

Using a homogenous sample of 1962 quasars with redshift 3.0≤z≲4.5 drawn from the Sloan Digital Sky Survey (SDSS), we study the relationships between radio loudness, virial black hole (BH) mass and Eddington ratio (accretion rate relative to the Eddington limit). For the radio-detected objects, we find a significant (>99.5 per cent) anticorrelation between radio loudness R parameter and BH mass, consistent with previous studies of low-redshift radio-loud quasars. The truly radio-loud quasars (R>30) are found to be confined to M _BH≲10¹⁰ M_⊙ within our sample. We also find that R is only weakly correlated with Eddington ratio L _bol/L _Edd. Combined with previous results on the low-redshift R−L _bol/L _Edd relation, this result indicates no strong L _bol/L _Edd dependence of R at L _bol/L _Edd≳10⁻². On the other hand, the large scatter in these relationships suggests that other physical properties such as BH spin and quasar clustering must also play an important role in quasar radio emission.  相似文献   

勘探早—中期的沉积盆地有效烃源岩综合预测方法探讨——以北黄海某盆地为例     

冯常茂  白志琳  涂广红  王后金  胡小强  杜民 《海相油气地质》2013,(2):65-71

针对勘探程度较低的地区,提出了一套有效烃源岩的综合预测方法。其基本思路是,从钻井出发,井震结合,按由点到面、由剖面到平面的顺序分五步进行:确定有利沉积相带;确定烃源岩平面分布;划分区域沉积相分布;确定平面热演化分布;有效烃源岩分布预测。利用该方法,对北黄海某盆地侏罗系SQ1层序进行了有效烃源岩预测。  相似文献   

Hydrogeochemistry and possible sulfate sources in karst groundwater in Chongqing, China   总被引：2，自引：0，他引：2  

Junbing Pu  Daoxian Yuan  Cheng Zhang  Heping Zhao 《Environmental Earth Sciences》2013,68(1):159-168

Groundwater from karst subterranean streams is among the world’s most important sources of drinking water supplies, and the hydrochemical characteristics of karst water are affected by both natural environment and people. Therefore, the study of karst groundwater hydrochemistry and its solutes’ sources is very important to ensure the normal function of life support systems. This paper focused on the major ion chemistry and sulfate isotope of karst groundwater in Chongqing for tracing the sulfate sources and related hydrochemical processes. Hydrochemical types of karst groundwater in Chongqing were mainly of the Ca-HCO₃ type or Ca(Mg)-HCO₃ type. However, some hydrochemical types were the K + Na + Ca-SO₄ type (G25 site) or Ca-HCO₃ + SO₄ type (G26 and G14 sites), indicating that the hydrochemistry of these sites may be strongly influenced by anthropogenic activities or unique geological characteristics. The δ³⁴S-SO₄ ^2? of collected karst groundwater sample fell into a range of ?6.8 to 21.5 ‰, with a mean value of 5.6 ‰. In dolomite aquifer, the δ³⁴S-SO₄ ^2? value ranges from ?4.3 to 11.0 ‰, and in limestone aquifer, it ranged from ?6.8 to 21.5 ‰. The groundwater samples from different land use types showed distinctive δ³⁴S-SO₄ ^2? value. The δ³⁴S-SO₄ ^2? value of groundwater samples had range of ?6.8 to 16.7 ‰ (mean 4.0 ‰, n = 11) in cultivated land areas, 1.5–21.5 ‰ (mean 7.2 ‰, n = 20) in forested land areas, and ?4.3 to 0.8 ‰ (mean ?1.7 ‰, n = 2) in coalmine areas. The δ³⁴S-SO₄ ^2? values of groundwater samples collected from factory area and town area were 2.2 and 9.9 ‰, respectively. According to the δ³⁴S information of potential sulfate sources, this paper discussed the possible sulfate sources of collected karst groundwater samples in Chongqing. The variations of both δ³⁴S and 1/SO₄ ^2? values of the groundwater samples indicated that the atmospheric acid deposition (AAD), dissolution of gypsum (GD), oxidation of sulfide mineral (OS) or anthropogenic inputs (SF: sewage or fertilizer) contributed to sulfate in karst groundwater. The influence of oxidation of sulfide mineral, atmospheric acid deposit and anthropogenic inputs to groundwater in Chongqing karst areas was much widespread. For protecting, sustaining, and utilizing the groundwater resources, the sewage possibly originating from urban, mine or industrial area must be controlled and treated, and the use of fertilizer should be limited.  相似文献   

用色度空间变换处理的组合SPOT图像进行城市土地利用现状调查     

濮静娟  阎守邕  周艺 《遥感学报》1989,(2)

组合SPOT图像是由多波段和全色波段按三种不同方式组合的。其中图像D是经色度空间坐标系统变换和边缘增强处理的,在唐山城区土地利用调查中效果最好。在1:29600的图像D上能识别5个二级类型和17个三级类型。土地利用图的判读精度约90％。文中还详述了分类体系和土地利用调查的判读标志。  相似文献   

缝洞型碳酸盐岩储层多类多尺度建模方法研究:以塔河油田四区奥陶系油藏为例   总被引：2，自引：0，他引：2       下载免费PDF全文

侯加根  马晓强  刘钰铭  赵彬 《地学前缘》2012,19(2):59-66

碳酸盐岩缝洞型储层历经多期构造运动以及强烈的风化、剥蚀和淋滤作用,储集空间类型多样,形态极不规则且随机分布,导致储层三维空间描述困难,现有的碎屑岩储层建模方法难以直接借鉴。文中提出碳酸盐岩缝洞型储层应该按照大型洞穴、溶蚀孔洞、大尺度裂缝、小尺度裂缝的"多类多尺度建模"的基本思路。以钻井和地震识别成果作为大型洞穴确定性数据,以地震波阻抗的大型洞穴发育概率体作为井间约束数据,在垂向岩溶分带和平面古地貌分区的岩溶相控下,采用具有趋势的序贯指示模拟方法,建立大型洞穴离散分布模型;以大型洞穴分布作为"相控"约束条件,以井孔解释的溶蚀孔洞作为硬数据,采用序贯指示模拟算法,建立溶蚀孔洞随机分布模型;根据蚂蚁体地震属性自动拾取的断裂信息,人机交互补充和修正地震解释断层数据,建立确定性的大尺度裂缝离散分布模型;基于大尺度裂缝离散分布模型建立井间裂缝发育概率体,根据井孔裂缝密度、裂缝产状,结合退火模拟和基于目标的示性点过程模拟方法,建立小尺度裂缝离散分布模型。以塔河油田四区奥陶系缝洞型油藏为例,建立研究区缝洞型储集体空间展布模型,再现缝洞型储层的结构形态。  相似文献   

Tracing the sources of strontium in karst groundwater in Chongqing, China: a combined hydrogeochemical approach and strontium isotope     

Junbing Pu  Daoxian Yuan  Cheng Zhang  Heping Zhao 《Environmental Earth Sciences》2012,67(8):2371-2381

Groundwater quality in karst regions is largely controlled by natural processes and anthropogenic activities. Over the past 10?years, dissolved Sr and its radiogenic isotope, ⁸⁷Sr/⁸⁶Sr, were widely used to trace the sources of solutes in groundwater. However, there is little research about hydrogeochemistry and Sr isotopic compositions of the karst groundwater in Chongqing karst area. In this paper, thirty-five representative karst groundwater samples were collected from different aquifers (limestone and dolomite) and various land use types. Hydrochemical types of karst groundwater in Chongqing were mainly of the Ca-HCO₃ type or Ca(Mg)-HCO₃ type. The dissolved Sr concentrations of the studied groundwater ranged from 0.57 to 15.06???mmol/L, and the ⁸⁷Sr/⁸⁶Sr varied from 0.70751 to 0.71627. The groundwater samples from different aquifers and land use types showed distinctive dissolved Sr concentrations and ⁸⁷Sr/⁸⁶Sr. The very positive relationship between Ca/Sr and Mg/Sr in dolomite and limestone aquifers suggests that Ca, Mg and Sr element come mainly from the release of carbonate rock under the groundwater?Crock?CCO₂ gas interaction. According to the ⁸⁷Sr/⁸⁶Sr ratio, the Sr element in karst groundwater in Chongqing was controlled by the weathering of limestone, dolomite and silicate rock (allogenic water in a non-karst area). The relationship ⁸⁷Sr/⁸⁶Sr versus Sr²⁺/[K⁺?+?Na⁺] shows that the anthropogenic inputs also obviously contribute to the Sr contents. The research results show that the karst groundwater in Chongqing is facing serious crisis of water quality, and needs to be protected further.  相似文献   

基于实测光谱和SRF的稀疏植被区MODIS积雪信息提取     

刘艳  李杨  张璞 《国土资源遥感》2013,25(1):26-32

以新疆准噶尔盆地古尔班通古特沙漠为研究区,以中等分辨率成像光谱仪(MODIS 1B)数据为例,辅以MODIS光谱响应函数(SRF)和全波段光谱仪(ASD)准同步采集的雪面反射光谱,运用线性光谱混合模型(LSMM)实现了稀疏植被区积雪遥感信息提取.结果表明:①利用SRF对雪面反射光谱进行端元光谱到像元光谱的转换,生成对应于MODIS1-7波段的离散光谱,将其与用最小噪声分离(MNF)变换和像元纯度指数(PPI)法获得的MODIS影像端元光谱进行对比,发现MODIS1波段光谱值远大于转换光谱值,MODIS2-7波段光谱值与转换光谱值接近;②MODIS2-7波段影像端元光谱值适用于LSMM估算稀疏植被区积雪分量,积雪分量估算值与归一化差分积雪指数(NDSI)拟合结果显示,剔除MODIS1波段后估算的积雪分量与NDSI的相关性显著提高,表明所提取的积雪分量可以作为估算积雪的典型指数.  相似文献   

一种针对目的层均匀成像的自动加密炮点方法(英文)     

赵虎  尹成  侯朋军  蒲龙川  黄勇  苑国辉 《应用地球物理》2013,(2):222-228,237

地震成像质量是储层预测的关键,提高成像质量的方法很多,有些依靠先进的处理手段,有些通过改变野外采集方式,而在采集中的很多方法是依靠炮点数目的增加,同时又不考虑目的层能量均匀性,是近似盲目的加炮方式,这增加了采集成本。本文提出一种全新的方法,该方法通过加密炮点方式,从而确保目的层阴影区的能量最大程度提高,为了验证方法的有效性,设计了一个二维和三维模型,利用正演、加炮和深度偏移等手段获取深度偏移剖面,模型结果表明,该方法优于以往整体加密的方法,选择的是最合适和最经济的炮点数进行加密,不但经济高效,而且大大地提高了目的层成像质量。  相似文献