基于GIS的市级城镇地籍管理信息系统设计研究

讨论了利用GIS技术进行市级城镇地籍管理系统建设的思路,进行了系统功能设计,包括基于矢量数据的建库系统和基于工作流技术的日常地籍管理系统,并对系统建设的关键技术进行了探讨。     

A correction technique for false topographic perception of remote-sensing images based on an inverse topographic correction technique

The false topographic perception phenomenon (FTPP) refers to the visual misperception in remote-sensing images that certain types of terrains are visually interpreted as other types in rugged lands, for example, valleys as ridges and troughs as peaks. For this reason, the FTPP can influence the visualization and interpretation of images to a great extent. To scrutinize this problem, the paper firstly reviews and tests the existing FTPP-correction techniques and identifies the inverse slope-matching technique as an effective approach to visually enhance remote-sensing images and retain the colour information. The paper then proposes an improved FTPP-correction procedure that incorporates other image-processing techniques (e.g. linear stretch, histogram matching, and flat-area replacement) to enhance the performance of this technique. A further evaluation of the proposed technique is conducted by applying the technique to various study areas and using different types of remote-sensing images. The result indicates the method is relatively robust and will be a significant extension to geovisual analytics in digital earth research.     

无人机倾斜摄影测量在房屋建筑面积测算中的应用

针对目前房屋建筑面积测量外业工作强度大、测量精度低、成图效率低等主要问题,本文提出了基于无人机倾斜摄影测量的房屋建筑面积测算方法。首先从无人机倾斜摄影、实景三维建模、数字正射影像制作、三维数字化测图、图件制作和面积指标计算等方面进行了研究,然后对试验结果进行了精度评定。结果表明,地形图平面位置中误差为4.6 cm,高程中误差为4.2 cm,房角点点位中误差为4.6 cm,建筑物边长中误差为4.5 cm,房屋建筑物面积较差小于城市商品房二级精度面积限差,各项精度均符合国家标准规范要求,该方法用于房屋建筑面积测算是可行的。     

区域中尺度模式云微物理参数化方案特征及其在中国的适用性

云微物理参数化方案在数值模式中起着重要的作用,是影响数值天气预报和气候预测准确性的最大因素。系统回顾了中尺度数值模式中云微物理参数化方案的研究进展,并统计分析了最近十余年云微物理参数化方案在中国范围内的敏感性试验研究成果。Lin方案和Rutledge-Hobbs方案奠定了中尺度模式中云微物理参数化方案的基础,其他方案都是直接或间接在这2个方案的基础上从多方面改进而形成的。这些改进主要体现在:①水凝物粒子分类数目;②冰核活化;③粒子谱分布描述函数;④粒子谱截距的取值;⑤粒子间相互转换阈值大小的设定。中国范围内云微物理参数化方案敏感性试验研究成果统计表明,使用WRF模式中Lin方案的模拟效果较好,MM5模式采用Goddard和Reisner方案效果较好。     

城市下垫面对渤海湾海风锋特征影响的一次数值试验

海风锋与沿海强对流天气密切相关,而城市化发展对沿海地区下垫面的改变会对海风锋特征产生影响。鉴于此,本文利用耦合了新一代城市物理方案UCP-BEM(Urban Canopy Parameterization-Building Energy Model)的WRF(Weather Research and Forecasting)模式开展数值试验分析了城市下垫面对渤海湾海风锋特征的影响。结果显示:城市下垫面高粗糙度对低层海风风速的明显削弱造成海风锋往内陆推进距离稍减,低层辐合和上升运动减弱;城市下垫面较大的向上感热通量和较小的向上水汽通量以及高粗糙度对海风的削弱的共同作用造成冷湿海风对低层大气的降温和增湿幅度减弱;高粗糙度的城市下垫面对海风环流的摩擦力效应使得海风得到抬升,这导致了冷湿海风对低层大气的降温和增湿的垂直范围得到提升;受这些结果影响,海风锋背后低层有效位能减小,但垂直分布范围扩大,从而造成对流抑制高值区抬升,同时海风锋背后的静力不稳定区变厚,其上面的动力不稳定区则变薄,但不稳定区总厚度基本不变。     

Numerical simulation of the sudden rainstorm associated with the remnants of Typhoon Meranti (2010)

The Advanced Research Weather Forecasting (ARW) model was used to simulate the sudden heavy rainstorm associated with the remnants of Typhoon Meranti in September 2010. The results showed that the heavy rainfall was produced when the remnant clouds redeveloped suddenly, and the redevelopment was caused by rapid growth of micro/mesoscale convective systems (MCSs). As cold air intruded into the warm remnant clouds, the atmosphere became convectively unstable and frontogenesis happened due to strong wind shear between weak northerly flow and strong southwesterly flow in the lower levels. Under frontogenesis-forcing and warm-air advection stimulation in updrafts, vertical convection developed intensely inside the remnant clouds, with MCSs forming and maturing along the front. The genesis and development of MCSs was due to the great progress vertical vorticity made. The moist isentropic surface became slantwise as atmospheric baroclinity intensified when cold air intruded, which reduced the convective instability of the air.Meanwhile, vertical wind shear increased because the north cold air caused the wind direction to turn from south to north with height. In accordance with slantwise vorticity development (SVD), vertical vorticity would develop vigorously and contribute greatly to MCSs. Buoyancy, the pressure gradient, and the lifting of cold air were collectively the source of kinetic energy for rainfall. The low-level southwesterly jet from the western margin of the Western Pacific Subtropical High transported water and heat to remnant clouds. Energy bursts and continuous water vapor transportation played a major role in producing intense rainfall in a very short period of time.     

基于层次分析法的江门市新会区雷电灾害风险区划

利用雷电探测分析系统和地基闪电定位系统(LLS)资料,以广东省江门市新会区11个镇(街)行政区域为评估单元,考虑人口密度以及经济发展因素,选取雷电灾害频数、地闪密度、人口密度、单位面积上的工农业总产值作为评估指标,建立层次分析模型,得到新会区的雷电灾害风险区划。结果表明:新会区会城街道辖区具有极高的雷电灾害风险值;司前镇具有高雷电灾害风险值;大泽镇、古井镇、三江镇、双水镇、睦洲镇具有中等雷电灾害风险;其他镇雷电灾害风险值较低;无极低雷电灾害风险区。     

The joint driving effects of climate and weather changes caused the Chamoli glacier-rock avalanche in the high altitudes of the India Himalaya

Science China Earth Sciences - Ice avalanches are one of the most devastating mountain hazards, and can pose a great risk to the security of the surrounding area. Although ice avalanches have been...     

2008年华南前汛期致洪暴雨特征及其对比分析

着重对2008年华南前汛期持续性致洪暴雨的降水特征及成因进行了天气尺度的研究,并且对比分析了其与20世纪90年代以来华南前汛期洪灾较为严重的几年(1994、1998和2005年)的降水和环流场特征异同,主要得到以下结果:(1)根据影响系统和雨区分布的不同,将2008年华南前汛期降水过程分为4个阶段.第1阶段(5月26-...     

Erratum to：A Case Study of the November 2012 Mixed Rain-Snow Storm over North China

正Erratum to:Acta Meteor Sinica DOI 10.1007/sl3351-013-0510-3The original version of this article unfortunately contained a mistake.The presentation of DOI number was incorrect.The corrected DOI number is 10.1007/sl3351-013-0512-1