Topographic controls on alpine treeline patterns on Changbai Mountain,China

The control mechanisms of topography on alpine treeline pattern are critical to understanding treeline dynamics and future changes. These mechanisms have not been understood quite well enough because of increasing human disturbance and low data resolution. In this study, the relationship between the treeline pattern and topography was analyzed based on high spatial resolution remote sensing data and a digital elevation model in an area in Changbai Mountain with little human disturbance. Future treeline patterns were also predicted. The results showed that(a) aspects with high solar radiation and low snow cover have a high coverage rate of trees,(b) the peak coverage rate of trees switches from low slopes(5°) to medium slopes(5°~25°) as the elevation rises because of the extreme environment,(c) the coverage rate of trees is a function that depends on environmental factors controlled by topography,(d) the future treeline pattern is controlled by new temperature mechanisms, new environmental factors and the reallocation effect of topography. Our research implies that topography controls the treeline pattern and changes in the treeline pattern associated with global warming, due to the effect of global warming on environmental factors. This study may well explain the causes of heterogeneous changes in the treeline pattern in the horizontal direction as well as differences in treeline response to climate warming.     

Remote sensing survey and research on internal solitary waves in the South China Sea-Western Pacific-East Indian Ocean (SCS-WPAC-EIND)

Internal solitary waves (ISWs) are common mesoscale dynamic processes in the ocean that are spread throughout the world’s oceans. The South China Sea (SCS), Western Pacific (WPAC) and Indian Ocean (EIND) (SCS-WPAC-EIND) are areas where ISWs frequently occur. In particular, in the northern part of the South China Sea, Sulu Sea, Celebes Sea, Andaman Sea, Lombok Strait and northeastern part of Taiwan Island, ISWs exist almost year-round. Remote sensing is an important technique to carry out investigations and research on ISWs on a large scale. In particular, optical sensors represented by the Moderate Resolution Imaging Spectroradiometer (MODIS) can observe ISWs for a long time and on a large scale, while SAR sensors such as Sentinel-1 A/B can compensate for the deficiencies in optical sensors and comprehensively observe ISWs. Based on many years of remote sensing surveys of ISWs, this paper uses MODIS and Sentinel-1 satellite remote sensing images of more than 70 000 scenes from 2010 to 2020 to carry out survey studies of ISWs in the SCS-WPAC-EIND. The survey systematically gives the temporal and spatial distribution characteristics of ISWs in the SCS-WPAC-EIND and focuses on the analysis of the ISW characteristics in main areas in the SCS-WPAC-EIND, thereby providing basic data for further research on ISWs.     

Experimental Study on Scouring and Silting Deformation of Artificial Beach Under Storm Surge-Wave Coupling

With the increasing construction of artificial beach in coastal areas, it is of practical significance to study the beach surface deformation of artificial beach profile. Previous studies only focus on a single wave dynamic factor, and it is difficult to predict the beach deformation of artificial beach profile under the storm surge-wave co-action. To solve this problem, the cross-section physical model test method was used to study the beach surface deformation of a typical artificial beach pro...     

Experimental Investigation of the Response of Monopiles in Silty Seabed to Regular Wave Action

Excessive displacement responses of monopiles affect the serviceability of offshore structures. Related to complicated pile-seabed-wave interactions, the actual behavior of monopiles in silty seabed under periodic wave action remains unclear, and relevant studies in the literature are limited. A series of experiments were conducted in a wave flume containing single piles in silty seabed with relative density of 0.77 subjected to regular waves. Two stages of wave loading were applied successively...     

基于GIS的上海市控制性详细规划编制与审查管理系统的设计与建设

介绍了上海市控制性详细规划编制与审查管理系统的建设背景,通过分析目前规划部门的GIS应用现状,以及控规编制与审查管理的应用需求,从控规设计、审查、入库三个方面详细介绍了系统建设的功能模块设计与定位,明确了系统研究的主要目标和建设方向。     

An automatical infill shot method for uniform imaging of target layer

Seismic imaging quality is critical to describing reservoirs. There are many methods that can improve imaging quality; some rely on advanced processing means, whereas others rely on changing the field acquisition methods. However, most of the acquisition methods focus on improving imaging by using infill shots without considering the target-layer illumination energy. Moreover, total infill shooting greatly increases the acquisition cost. In this paper, we present a new method for maximizing the contribution to the target shadow area illumination by automatic local infill shooting. Thus, we designed 2D and 3D models and obtained the depth migration section by forward modeling, infill shots, depth migration, etc. The model results also show that by choosing the most appropriate number of shot points, we can enhance the shadow area energy and improve the target-layer imaging quality at low cost.     

地球自转对强震震中附近中小地震的影响

论述2008年5月12日四川汶川Ms8.0地震和2010年4月14日青海玉树Ms7.1地震前震中附近中小地震和地球自转季节性变化的关系,介绍1970年以来中国大陆其他14例M≥7.0地震震例.研究发现,在强震前几年时间内,震中附近地区的中小地震有偏向发生于地球自转速率季节性变化加速或者减速某一阶段的现象.该结果对深入认识地震与地球自转之间的关系具有一定启示意义,对地震预测具有一定指导意义.     

基于移动平台地震速报短信客户端(EQSMS)的设计与实现

通过地震速报短信客户端软件(EQSMS),当用户收到速报短信后即可实时查看速报震中的矢量地理信息、卫星影像信息和震中距等数据,便于应急人员对灾害评估和应急救援等及早做出反应和工作部署.     

《地震科技文献分类标引规则》的编制与形成

根据地震科技文献管理的实际和特点,制定了《地震科技文献分类标引规则》,弥补了地震科技文献管理中的一项空白,规范了地震科技文献分类标引的原则、基本规则和深度控制。