Spatio-temporal data model based on relational database system     

Sha Zongyao  Bian Fuling 《地球空间信息科学学报》2013,16(2):22-27

In this paper, the entity-relation data model for integrating spatio-temporal data is designed. In the design, spatio-temporal data can be effectively stored and spatiao-temporal analysis can be easily realized.  相似文献   

Effects of land cover type conversion on water exchange and climate change in the source area of the Yellow River     

Wang  Lijuan  Guo  Ni  Sha  Sha  Yang  Yang  Wang  Xiaoping  Hu  Die 《Theoretical and Applied Climatology》2022,149(1-2):525-536

Theoretical and Applied Climatology - The surface radiation and energy flux in the source area of the Yellow River are estimated by using the Moderate Resolution Imaging Spectroradiometer products...  相似文献   

基于Morgenstern-Price法的南京大报恩寺地宫稳定性分析     

王莎  谌文武  李鹏飞  孙光吉 《地震工程学报》2011,33(Z1)

处于中国南方潮湿多雨环境下的古代土遗址,易受雨水的冲刷和浸渍而导致土质松散及崩塌。本文以南京报恩寺地宫、塔基保护技术为研究对象,通过现场试验和变形监测,分析影响其稳定的因素并运用M-P法对其稳定性进行了计算,提出了适用于地宫加固的方案。  相似文献   

Stratigraphy of the Triassic?Jurassic Boundary Successions of the Southern Margin of the Junggar Basin, Northwestern China   总被引：2，自引：1，他引：1  

SHA Jingeng  Vivi VAJDA  PAN Yanhong  Linda LARSSON  YAO Xiaogang  ZHANG Xiaolin  WANG Yaqiong  CHENG Xiansheng  JIANG Baoyu  DENG Shenghui  CHEN Siwei  PENG Bo 《《地质学报》英文版》2011,85(2):421-436

The Triassic?Jurassic (Tr?J) boundary marks a major extinction event, which (~200 Ma) resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr?J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial settings leading to difficulties in linking marine and terrestrial sedimentary successions. Investigation based on palynology and bivalves has been carried out over a 1113 m thick section, which is subdivided into 132 beds, along the Haojiagou valley on the southern margin of the Junggar Basin of the northern Xinjiang, northwestern China. The terrestrial Lower Jurassic is conformably resting on the Upper Triassic strata. The Upper Triassic covers the Huangshanjie Formation overlaid by the Haojiagou Formation, while the Lower Jurassic comprises the Badaowan Formation followed by the Sangonghe Formation. Fifty six pollen and spore taxa and one algal taxon were identified from the sediments. Based on the key-species and abundance of spores and pollen, three zones were erected: the Late Triassic (Rhaetian) Aratrisporites?Alisporites Assemblage, the Early Jurassic (Hettangian) Perinopollenites?Pinuspollenites Assemblage, and the Sinemurian Perinopollenites?Cycadopites Assemblage. The Tr?J boundary is placed between bed 44 and 45 coincident with the boundary between the Haojiagou and Badaowan formations. Beds with Ferganoconcha (?), Unio?Ferganoconcha and Waagenoperna?Yananoconcha bivalve assemblages are recognized. The Ferganoconcha (?) bed is limited to the upper Haojiagou Formation, Unio?Ferganoconcha and Waagenoperna?Yananoconcha assemblages are present in the middle and upper members of the Badaowan Formation. The sedimentary succession is interpreted as terrestrial with two mainly lake deposit intervals within Haojiagou and Badaowan formations, yielding fresh water algae and bivalves. However, the presence of brackish water algae Tasmanites and the marine?littoral facies bivalve Waagenoperna from the Badaowan Formation indicate that the Junggar Basin was influenced by sea water caused by transgressions from the northern Tethys, during the Sinemurian.  相似文献   

土地利用变化对延安市生态服务价值的影响   总被引：2，自引：0，他引：2  

庞莎  刘康  冀文慧 《地下水》2011,(1):154-157

利用延安市2001-2007年土地利用基础数据,计算土地利用动态度,并在Costanza生态系统服务价值理论基础上,结合谢高地等的中国生态系统生态服务价值当量因子表,计算出延安不同生态系统单位面积生态服务价值。并依此尝试计算延安市2001年至2007年延安市生态系统服务价值量。研究发现,2007延安市的生态系统服务价值将达到424.28亿元,比2001年增加28.79亿元,增长率为7.28%;各种土地利用方式的生态系统服务价值的敏感性指数(CS)均小于1,表明其对生态系统的价值变化是缺乏弹性的。  相似文献   

地铁行车荷载作用下淤泥质黏土累积特性的试验研究     

唐益群  李珺  刘莎  周洁  王建秀  杨坪 《工程地质学报》2011,19(4):460-466

中国上海地区地铁隧道一般位于第④层淤泥质黏土层中,在地铁行车荷载作用下隧道周围土体变形引起隧道轴线沉降,有些区段隧道轴线沉降量已超过20cm,引起了一系列环境地质问题.本文以上海第④层原状淤泥质黏土为研究对象,通过室内循环三轴试验,模拟地铁运营过程中产生的振动荷载,研究荷载作用下上海淤泥质黏土的累积应变、孔隙水压力及再...  相似文献   

单基站CORS系统在胜利油区石油天然气井位测量中的应用     

苏艳红  刘沙 《山东地质》2011,(5):30-32,38

随着GPS技术的飞速前进,利用网络RTK技术建立的连续运行卫星定位系统已成为GPS应用的发展热点之一。通过对胜利油田单基站CORS系统的组成、功能及在胜利油区石油天然气井位测量中的应用方式及精度分析的论述,对单基站CORS系统在石油天然气井位测量中的现实意义和应用前景进行了展望。  相似文献   

中国现代干旱灾害的时空特征^*   总被引：28，自引：0，他引：28  

李克让  尹思明 《地理研究》1996,15(3):6-15

本文提出了一个考虑前期降水短缺影响的干旱指数。利用1951-1991年逐月全国160个站的降水资料划分干旱等级,分析了我国干旱,包括多旱、重旱和持续干旱的区域分布,指出我国主要有四大干旱中心;分析了干旱随时间的变化,发现全国及多数区域的现代干旱存在着线性增长的趋势。最后利用全国干旱受灾和成灾面积讨论了干旱的影响,指出全国近代干旱受灾和成灾面积存在着三个高值期,且总体线性增长趋势也很明显。  相似文献   

Jurassic sedimentary features and tectonic settings of southeastern China   总被引：1，自引：0，他引：1  

LiangShu Shu  Yan Wang  JinGeng Sha  ShaoYong Jiang  JinHai Yu  YanBin Wang 《中国科学D辑(英文版)》2009,52(12):1969-1978

Two types of the Jurassic basins are distinguished in SE China based on their geodynamic features: the Late Triassic-Early Jurassic post-orogenic basins and the Middle Jurassic intra-continental extensional basins. The Lower Jurassic sequence shows a change from coarse- to fine-grained accumulation, suggesting a gradually deepening depositional environment from river to shore-lake and to deep-water lake. In contrast, the Middle Jurassic accumulation was changed from claystone to conglomerate along the coastal provinces in SE China, indicative of an initial crustal uplift. The Wuyi Mountains have been a paleogeograghic separating zone since the Middle Jurassic. The Late Jurassic strata are absent in most areas of SE China. A large-scale bimodal intra-continental rift-type volcanism occurred during the Middle Jurassic along a 40–60 km wide and 200 km long area in western Fujian and southern Jiangxi provinces, which is most likely the strongest volcanism in SE China since the Cambrian. The SHRIMP zircon U-Pb analyses on the rhyolite from the Dongkeng basin in the southern Jiangxi area yield a concord U-Pb age of 160±0.5 Ma, providing an upper age limit for the bimodal volcanic eruption. The analyses of the basin features indicate a change of the depositional environment during the interval from Middle Triassic to Late Triassic from a shallow-sea to an intra-continent in SE China in response to the strong collision between the Yangtze and North China Blocks. Sedimentary structures record a southward direction of Early Jurassic paleo-currents, reflecting that their source areas were to the north side. We propose that the Wuyi region was uplifted as early as Middle Jurassic, followed by a wide E-W-trending extended depression and bimodal volcanism in the western foot of the Wuyi Mountains. Presumably the uplift of the Wuyi domain changed the Middle Jurassic paleogeographic outline and formed the transformational tectonic regime from compression to extension as a tectonic response to the Pacific plate subduction.  相似文献   

美姑县乐约乡波阿莫超大型山体滑坡成因分析及防治对策   总被引：1，自引：0，他引：1  

沙德智  尹丕华  陈关顺 《四川地质学报》2000,(3)

在野外调查的基础上 ,对滑坡的形成条件 ,诱发因素 ,分布特点 ,危害程度及发展趋势等内容进行了全面评价 ,并提出了相应的防治措施。  相似文献