Shell model representation as a substitute of LoD3 for 3D modeling in CityGML

The OGC standard for 3D city modeling is widely used in an increasing number of applications.It defines five consecutive Levels of Detail(LoD0 to LoD4 with increasing accuracy and structural complexity),in which LoD3 includes all exterior appearances and geometrical details and subsequently requires much storage space.A new LoD is introduced as shell model with the exterior shell of the LoD3 model and the opening objects like windows,doors as well as smaller faade objects are projected onto walls.In this paper,a user survey is presented.The results of this survey show that the shell model can give users almost the same visual impression as the LoD3 model.Furthermroe,algorithms are developed to extract the shell model from LoD3 model.Experiments show that this shell model can reduce up to 90% storage of the original LoD3 model.Therefore,on one hand it can be used as a substitute for a LoD3 model for the visualization on small displays.On the other hand,it can be treated as a sub-level of detail(SLoD3) in CityGML,since it retains almost the same amount of information but requires much less storage space.     

北京快速更新循环预报系统（BJ-RUC）要素预报质量评估

使用自动站观测资料对BJ-RUC系统预报的北京15个观测站的逐时2 m温度、相对湿度、1小时降水量和风速等地面要素质量进行检验评估。结果表明：BJ-RUC系统预报的2 m温度、相对湿度和风速与实况具有一致的变化趋势,但各要素的预报性能不尽相同。结果表明：（1）对于2 m温度的预报,±1℃误差的准确率为0.2～0.5,±2℃误差的准确率更高;预报性能与预报时效无明显关系;温度预报准确性与季节和日变化有关,春、秋季优于冬、夏季,夜间优于白天。（2）对相对湿度的预报整体偏低,夏季白天偏低、冬季白天偏高。（3）对1小时降水的预报,无论全年还是夏季,晴雨预报准确率很高;对0.1 mm降水的TS评分在0.2左右。（4）对不同站点的预报性能存在明显差异。对平原地区,即海拔高度较低的站点预报性能相对较好,15个站点中,对北京的代表站点（南郊观象台）的预报最为准确;对山区站点的预报性能相对较差,对海拔最高的延庆站的预报性能最差。总体来说,BJ RUC对站点要素预报的变化趋势较好,预报准确率较高,具有很好的参考价值,但要素预报与季节、日变化及海拔高度等因素有关.具体应用时还需做适当订正。     

Study on Precise Location and Structure of Earthquakes in the Shanxi Reservoir,Zhejiang Province

The Shanxi reservoir earthquakes are significant seismic events in southern Zhejiang Province in recent years, an area with fewer and weaker earthquakes. The seismicity showed an intermittent characteristic and group distribution. The epicenters located by the seismic network did not show a predominant direction and the seismogenic structure is not clear. In the study, the nonlinear imaginary wave travel time equation was linearized and solved, and the source position, initial imaginary velocity and travel ...     

DSQ水管仪和SSQ-2I水平摆效能对比研究

SSQ-2I型水平摆仪器和DSQ水管仪同属倾斜类前兆仪器,两者观测原理不同,但观测物理量一致.相对于水管仪而言,SSQ-2I型水平摆属于新型仪器,有关其运行效能的评价很少.延庆地震台从2007年开始两种仪器同场地观测,通过年变幅度、滤波残差、周期分析、Venedikov调和分析、相关性分析、抗干扰能力等角度,对两种仪器...     

数学形态滤波在地磁数据干扰抑制中的应用

针对地磁观测信号容易受仪器噪声和脉冲噪声等干扰,提出一种根据干扰特征对地磁信号进行数学形态滤波的新方法.通过谐波拟合地磁日变形态信号中添加随机噪声和瞬态脉冲噪声,模拟抑制含有这类干扰的地磁信号.通过数值模拟,验证了数学形态滤波具有抑制脉冲干扰地磁信号噪声,降低仪器噪声干扰,保留地磁信号特征,提高地磁信号信噪比等良好的特...     

西安市地震应急指挥技术系统设计与实现

本文从系统总体架构设计、系统功能设计与应用成果、系统特色4个方面简要介绍了西安市地震应急指挥技术系统设计与实现情况.本系统是首个应用于省会城市地震应急工作,并基于国产Server GIS软件平台研制开发出的地震应急指挥技术系统,可为大城市地震应急指挥技术系统的建设与发展提供可借鉴的经验.     

山西高温天气的环流特征及流型配置研究

利用1958年-2008年高低空气象观测资料以及山西省气象信息中心归档的109站1958年-2008年的原始气象记录月报表及其信息化产品资料,分别以最高气温≥35℃、≥37℃、≥40℃为指标,研究山西高温日的时空分布、变化趋势及环流特征。结果表明：a）山西高温日最早出现在4月中旬,最晚出现在9月中旬,≥35℃、≥37℃和≥40℃的高温日6月下旬最多;b）高温日数有随纬度、随海拔的升高而减少,有西部多于东部、南部多于北部、盆地多于山区的空间分布特征。≥40℃的高温区域主要集中在运城和临汾地区;C）1984年-2008年,35℃以上的高温日数整体呈上升趋势;1979年-2008年,30年间高温站次以153站次,10a的趋势增多。20世纪90年代以后,不仅高温日数增多,而且高温持续时间、强度、范围都有增强趋势;d）影响山西高温的500hPa环流形势主要有副高纬向性、副高经向型以及大陆高压（脊）控制型3类。在特定的流型配置下,T850≥25℃、T700≥13℃,T850≥26℃、T700≥14℃,T850≥28℃、T700≥15℃,T850≥32℃、T700≥16℃是山西省不同区域、不同风向影响时,≥35℃、≥37℃、≥40℃高温天气预报的临界值。     

气象综合信息电子屏在新农村建设中的应用及思考

通过对气象综合信息电子屏应用情况进行分析和探讨,得出一些应用初步结论和思考,以期抛砖引玉,使该项工作能在新农村建设中加快应用步伐,为真正解决农村信息覆盖"最后一公里"的瓶颈提供参考.     

Development of 57 novel polymorphic microsatellite markers in half-smooth tongue sole (Cynoglossus semilaevis)

Half-smooth tongue sole (Cynoglossus semilaevis) is a promising species for aquaculture in China.The wild population of C. semilaevis is under threat from environmental factors. Microsatellite markers are very suitable for assessing genetic diversity. Four microsatellite-enriched libraries of half smooth tongue sole (Cynoglossus semilaevis) were constructed,from which 57 polymorphic microsatellites were isolated and characterized.The polymorphism of these microsatellites was assessed by genotyping in 30 ind...     

汶川地震灾后重建地区的人口容量分析

Assessment of population carrying capacity is a key task in the reconstruction planning of areas struck by disasters, in which the precision of estimation is required. This study developed a decision-making model for estimating the population capacity of the involved townships and cities in the 2008 Wenchuan Earthquake based on the assessment of the suitability for reconstruction of the areas. Through analysis, arable land resources were argued to be the critical constraint of population capacity in these areas. Then, the spatial differentiations of the post-quake development conditions across different regions were analyzed with respect to their natural environments, socio-economic development and quake damages. The expected levels of urbanization, family incomes and income structures, output levels of land, and the reliance of agricultural population on arable land were estimated by different regions. With these parameters, the population capacities of the involved townships and cities in three scenarios were estimated. The total population capacity of the entire areas is abundant compared with the actual post-quake population; however, the status of over-population substantially varies across space. It was suggested to put the emphasis of post-quake resettlement policy on those counties where earthquake had been the main causes of over-population. In the Full Recovery Scenario, three mountain counties were identified including Wenchuan, Beichuan and Maoxian, with a total over-population of about 100,000 people.