吉林省高温天气气候特征及其过程等级评估     

纪玲玲  袭祝香  陈卓  刘玉汐 《气象与环境学报》2020,36(3):49-54

利用1951—2018年吉林省50站逐日最高气温资料,采用气候倾向率、距平累积、灰色关联度、正态分布等方法分析了吉林省高温天气的时空分布特征、建立了吉林省高温过程综合指数、高温过程评估等级指标和气候重现期指标。结果表明：近68 a来,吉林省年平均高温日数总体呈增加趋势,气候倾向率为0.04 d/10 a。吉林省高温次数阶段性变化明显,1959—1996年为偏少时段;1951—1958年、1997—2018年为偏多阶段。吉林省高温天气主要出现在6月中旬至8月中旬,其中7月下旬最多,8月上旬次多。西部为高温的高发区,吉林省年平均高温日数呈自西向东减少特征。对高温过程进行了等级划分,并给出等级及气候重现期评估指标,对于高温过程,可采用综合指数评估指标和各分项评估指标进行评估,便于在决策业务中应用。  相似文献   

中国近50a积雪变化时空特征     

希爽  张志富 《干旱气象》2013,(3):451-456,470

利用1961～2012年中国1400个站点逐日积雪增量、积雪日数和气温稳定通过0℃日数资料,对我国积雪时空变化特征进行了分析研究。结果表明：我国积雪主要分布在新疆北部地区、东北和内蒙古东北部地区及青藏高原地区,年积雪增量均超过50era;在年代际变化中,1991～2000年我国大部分地区积雪增量偏少;在对我国5个区域的趋势分析中,新疆北部地区、东北和内蒙古东北部地区积雪量有显著增加趋势,积雪日数的变化趋势均不显著,气温稳定通过0oC日数均呈显著减少。  相似文献   

Computer simulation of a semi-continuous open-pit mine haulage system     

Shiji Peng  Daxian Zhang  Yongfeng XI 《Geotechnical and Geological Engineering》1988,6(3):267-271

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土地信息多级网格及其应用     

杨永崇  席晶 《测绘科学》2012,(4):102-103,116

多比例尺空间数据的表达与处理是GIS的一个固有问题,本文用土地信息多级网格代替多级土地数据库中的多比例尺数据库及其多比例尺表达,以解决多级土地数据库建库过程中制图综合带来的地类数据变化问题,同时也为土地数据的共享提供了方便.  相似文献   

基于立体标定靶的扫描仪与数码相机联合标定     

赵松  西勤  刘松林 《测绘科学技术学报》2012,(6):430-434

地面3维激光扫描仪是一种新型测量仪器,应用领域广泛。随着3维激光扫描技术和CCD传感器技术的不断发展,越来越多的3维激光扫描仪配有内置或者外置的数码相机。在对目标的描述上,点云和影像数据各有优势,扫描仪和数码相机的联合标定可为实现两者的优势互补提供基础。目前扫描仪和数码相机的联合标定主要是基于扫描区域的几何特性或者基于2维平面标定靶,这两种联合标定方法具有一定的局限性。这里在设计3维立体标定靶的基础上,提出了一种基于3维立体标定靶的联合标定方法。经过实验验证了联合标定方法的有效性和稳健性。  相似文献   

一种新的激光点云数据精简方法     

喜文飞  方源敏  李帅  李健 《测绘工程》2012,21(4):38-40

三维激光扫描技术是最近几年在测量方面发展起来的一个研究热点。提出利用点云模型中相邻三角形夹角的大小来对点云数据进行直接精简的方法,在matlab平台下,通过编程实现点云数据的压缩。将精简的点云数据通过编程重新构建三角网,最后在Geomagic软件中建模,通过与原始模型进行对比,新方法的压缩效果比较理想。  相似文献   

STUDY OF THE EFFECTS OF REDUCING SYSTEMATIC ERRORS ON MONTHLY REGIONAL CLIMATE DYNAMICAL FORECAST     

曾新民  席朝笠 《热带气象学报(英文版)》2009,15(1):102-105

A nested-model system is constructed by embedding the regional climate model RegCM3 into a general circulation model for monthly-scale regional climate forecast over East China. The systematic errors are formulated for the region on the basis of 10-yr (1991-2000) results of the nested-model system, and of the datasets of the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) and the temperature analysis of the National Meteorological Center (NMC), U.S.A., which are then used for correcting the original forecast by the system for the period 2001-2005. After the assessment of the original and corrected forecasts for monthly precipitation and surface air temperature, it is found that the corrected forecast is apparently better than the original, suggesting that the approach can be applied for improving monthly-scale regional climate dynamical forecast.  相似文献   

Study on the Effects of Land Surface Heterogeneitiesin Temperature and Moisture on Annual Scale Regional Climate Simulation     

ZENG Xinmin  LIU Jinbo  MA Zhuguo  SONG Shuai  XI Chaoli  WANG Hanjie 《大气科学进展》2010,27(1):154-163

The ``combined approach', which is suitable to represent subgrid land surface heterogeneity in both inter-patch and intra-patch variabilities, is employed in the Biosphere/Atmosphere Transfer Scheme (BATS) as a land surface component of the regional climate model RegCM3 to consider the heterogeneities in temperature and moisture at the land surface, and then annual-scale simulations for 5 years (1988--1992) were conducted. Results showed that on the annual scale, the models response to the heterogeneities is quite sensitive, and that the effect of the temperature heterogeneity (TH) is more pronounced than the moisture heterogeneity (MH). On the intraannual scale, TH may lead to more (less) precipitation in warm (cold) seasons, and hence lead to larger intraannual variability in precipitation; the major MH effects may be lagged by about 1 month during the warm, rainy seasons, inducing ～6% more precipitation for some sub-regions. Additionally, the modeled climate for the northern sub-regions shows larger sensitivities to the land surface heterogeneities than those for the southern sub-regions. Since state-of-art land surface models seldom account for surface intra-patch variabilities, this study emphasizes the importance of including this kind of variability in the land surface models.  相似文献   

鄂尔多斯盆地盐池-定边地区长7烃源岩有机地球化学特征及沉积环境研究     

席胜利  刚文哲  杨清宇  陈果  刘亚洲  王宁  刘兰 《现代地质》2019,33(4):890-901

通过对鄂尔多斯盆地盐池-定边地区长7段烃源岩的分析,研究区长7段烃源岩有机碳平均含量为3.22%,生烃潜量均值为12.8 mg/g,氯仿沥青“A”均值为0.55%,可以划分为较好-好的烃源岩,具有良好的生烃潜力。利用有机岩石学分析、热解分析,并结合饱和烃生物标志物分析,发现研究区长7段烃源岩有机质类型以Ⅱ₁型和Ⅱ₂型为主,有机质以菌藻类生源为主,并伴有部分高等植物生源。烃源岩有机质成熟度R_o值介于0.42%~0.76%之间,并且热解T_max也主要集中在440~455 ℃之间,并且正构烷烃分布特征及甾、藿烷异构化参数说明烃源岩有机质处于低熟-成熟度阶段。根据饱和烃中甾藿烷参数、三环萜烷参数、伽马蜡烷指数、β-胡萝卜烷相对含量以及姥植比参数特征,研究区长7段烃源岩沉积环境为湖相淡水弱氧化-弱还原环境。  相似文献   

Applications of Light Stable Isotopes(C,O, H) in the Study of Sandstone Diagenesis: A Review     

XI Kelai  CAO Yingchang  LIN Miruo  LIU Keyu  WU Songtao  YUAN Guanghui  YANG Tian 《《地质学报》英文版》2019,93(1):213-226

This article reviews the applications of light stable isotope, including carbon, oxygen and hydrogen, in thestudies on origin and formation temperature of authigenic carbonate, quartz and clay minerals. Theoretical knowledge andanalytical methods for major light stable isotopes are introduced in detail. Negative and positive δ¹³C values indicatesignificant differences on the origin of carbonate cements. The δ¹⁸O value is an effective palaeotemperature scale forauthigenic minerals formation. Various fractionation equations between δ¹⁸O and temperature are proposed for carbonatecements, quartz cements and clay minerals, whose merit and demerit, applicable conditions are clarified clearly. Clumpedisotope analysis can reconstruct the temperature of carbonate precipitation with no requirement on the δ¹⁸O of initial waters,which makes temperature calculation of carbonate cements formation more convenient and accurate. Hydrogen and oxygenisotopes mainly reflect the origin of diagenetic fluid for clay mineral formation, providing reliable evidence for diageneticenvironment analysis. This work aims at helping researchers for better understanding the applications of light stable isotopein sandstone diagenesis.  相似文献