基于HBase的空间矢量数据存储模型设计与优化

数据存储模型是数据库模型的重要组成部分。本文针对目前关系型空间数据库发展过程中遇到的瓶颈问题以及采用HBase管理空间矢量数据存在的问题,在分析关系型空间数据库存储模型的基础上,将关系型数据库存储模式向HBase存储模式转换规则应用到空间矢量数据管理领域,提出了空间矢量数据关系存储模式向HBase存储模式转换方法,设计了一种空间矢量数据HBase存储模型。利用HBase的实体嵌套、反范式化、无模式等特性,对模型进行了优化完善。通过试验验证了在没有辅助索引情况下,本文设计的存储模型查询效率优于目前常用的基于HBase的空间矢量数据存储模型。     

多尺度快速匹配追踪多域联合地震反演方法

多尺度快速匹配追踪多域联合地震反演是一种通过地震数据多尺度分解的迭代反演方法.与此同时,在快速匹配追踪算法中引入低频模型约束,有效提高了收敛精度,使反演结果具有丰富的高低频信息.首先通过对大尺度地震资料进行反演得到低频背景.在此基础上,采用中尺度与小尺度地震数据进行逐级迭代用以获得高频数据,因而有效缓解了常规反演方法对于初始模型精度的依赖.最后利用理论模型与实际地震数据进行测试,通过与常规时间域反演方法的反演结果进行对比可以看出,本文方法在地层连续变化处依然可以对变化地层进行精确刻画,且在纵向分辨率提升的同时保持了较好的横向连续性.     

地震前地震活动周期谱特征及其应用

在对最大熵谱方法进行检验的基础上,应用这一方法,通过对24次6级以上地震的地震活动增强区内地震活动度的周期谱特征进行研究,得到如下认识:① 在孕震过程中,地震活动增强区内的活动在不同阶段,表现出的周期谱不同．正常时段的周期谱长周期与短周期并存,而震前阶段只存在短周期（平均为长周期的43％左右）,长周期消失;② 震前出现短周期的时间与震级有关．8级地震一般为震前数十年乃至上百年,7级地震一般为30年以上,而6级地震一般为20～30年．对于同震级地震,其出现短周期的时间还因地区的不同而不同,一般华北地区较西部地区长．应用坚固体孕震模式对以上特征进行了初步分析,提出了运用最大熵谱方法进行强大地震的趋势预测思路,并将此思路应用于实践,对云南武定6.5级和丽江7.0级两次地震进行了预测尝试．从而为6级以上地震的趋势预测提供了一种途径．      

乌鲁木齐天文站的耀斑预报

鉴于预报太阳耀斑的重要性和难度,我们在文中介绍了怎样用太阳色球望远镜观测太阳色球层的耀斑先兆（ 现象） ,并且根据太阳活动特点和十几年的观察经验及观测资料,综合分析,判断出太阳色球耀斑将要产生的大概时间,大致规模及耀斑在日面上的可能位置。通过第２２ 周峰年资料验证,准确率可达７０ ％ 。     

地震灾害风险评估及减灾策略研究——以贵州罗甸县为例

为探究贵州省地震灾害风险薄弱环节，减轻地震灾害风险，以贵州省罗甸县为示范，采用地震危险性概率分析方法对各乡镇进行危险性分析，开展地震灾害承灾体现场抽样调查，通过层次分析法和问卷调查的方式，首次构建乡镇级别的地震灾害风险和减灾能力指标体系，评估各乡镇地震灾害综合指数和程度，计算各乡镇地震灾害风险指数，确定红水河镇为高风险区、罗悃镇为中风险区、木引等7个乡镇为低风险区，并从建筑物设防、地震地质灾害及水库地震等角度剖析罗甸县地震灾害特点，从农村危房改造、移民搬迁、地质灾害防护及交通等方面提出减小地震灾害风险的建议。     

An optimal parameters-based geographical detector model enhances geographic characteristics of explanatory variables for spatial heterogeneity analysis: cases with different types of spatial data

ABSTRACT

Spatial heterogeneity represents a general characteristic of the inequitable distributions of spatial issues. The spatial stratified heterogeneity analysis investigates the heterogeneity among various strata of explanatory variables by comparing the spatial variance within strata and that between strata. The geographical detector model is a widely used technique for spatial stratified heterogeneity analysis. In the model, the spatial data discretization and spatial scale effects are fundamental issues, but they are generally determined by experience and lack accurate quantitative assessment in previous studies. To address this issue, an optimal parameters-based geographical detector (OPGD) model is developed for more accurate spatial analysis. The optimal parameters are explored as the best combination of spatial data discretization method, break number of spatial strata, and spatial scale parameter. In the study, the OPGD model is applied in three example cases with different types of spatial data, including spatial raster data, spatial point or areal statistical data, and spatial line segment data, and an R “GD” package is developed for computation. Results show that the parameter optimization process can further extract geographical characteristics and information contained in spatial explanatory variables in the geographical detector model. The improved model can be flexibly applied in both global and regional spatial analysis for various types of spatial data. Thus, the OPGD model can improve the overall capacity of spatial stratified heterogeneity analysis. The OPGD model and its diverse solutions can contribute to more accurate, flexible, and efficient spatial heterogeneity analysis, such as spatial patterns investigation and spatial factor explorations.     

基于地基微波辐射计资料对成都双流机场两次雷雨过程的分析

利用地基微波辐射计资料,比较了2017年7月成都双流机场的两次雷雨过程,根据天气形势分为"两高切变"和"东高西低"2类,在此基础上分析微波辐射计要素变化特征,结果表明:在垂直方向0～10 km,以相对湿度达到80%来区分干区和湿区,则两次过程前3 h,相对湿度在垂直方向均呈现"上下干、中间湿"三层结构,并早于近地层前2 h达到饱和状态;过程期间相对湿度呈现"上干、下湿"两层结构;过程结束后湿层抬高,低层变干。两次过程水汽含量充沛,保持在70 kg/m~2以上,峰值超过85 kg/m~2。每一次中阵雨发生后水汽含量都会短暂回落,但仍高于过程前的数值,不足2 h后再次发生中阵雨。由0℃线高度变化可知,降水过程中,暖区(温度≥0℃)内相对湿度≥90%;云中液态水含量主要分布于6 km以下,温度在0℃以上的液态水占比很高,故两次过程以暖云降水为主。雷雨前1 h左右有"低层气温上升,0℃层抬升,K指数、CAPE指数也明显增大"的典型特征。降水发生在相对湿度、水汽总含量、云中液态水含量和稳定度指数快速增长的波峰中。     

A mechanism for the formation of lopsided galaxies

This paper is concerned with the origin and existence of lopsided galaxies. A mechanism based on the distribution of dispersion velocities is suggested for the long-term maintenance of the lopsidedness.     

A relationship between solar activity and frequency of natural disasters in China

The relationship between the length of the solar cycle, a good indicator of long-term change in solar activity, and natural disasters (drought, flood, and strong earthquakes) in China during the last 108 years is analyzed. The results suggest that the length of solar cycle may be a useful indicator for drought/flood and strong earthquakes. When the solar activity strengthens, we see the length of the solar cycle shorten and more floods occur in South China and frequent strong earthquakes happen in the Tibetan Plateau,but the droughts in East China as well as the strong earthquakes in Taiwan and at the western boundary of China are very few. The opposite frequencies occur when the solar activity weakens. The current study indicates that the solar activity may play an important role in the climate extremes and behavior in the lithosphere.     

The status of the ecological environment and a proposed protection strategy in Sanya Bay,Hainan Island,China

Sanya Bay encompasses a high diversity of natural habitats, ranging from coral reefs, rocky and sandy shores and mudflats to mangroves. Seasonal physicochemical and biological investigations were conducted from 1998 to 1999 and again in April 2000. Water-related environmental quality in Sanya Bay is in good condition. The levels of dissolved oxygen, nitrogen, phosphorus and heavy metals are within the first class of National Seawater Quality Standards for China. Annual mean values of chlorophyll a of 0.93 mg m(-3) and phytoplankton primary productivity of 440.8 mgC m(-2)d(-1), respectively, were found in the waters, both of which show a significant correlation with inorganic nitrogen. A mean new productivity of 144.6 mgC m(-2) d(-1) was recorded in summer. Sanya Bay is rich in natural resources and biodiversity with 235 species of phytoplankton and 129 species of zooplankton identified in the survey. The annual mean abundance of phytoplankton and zooplankton were 1564 x 10 cells m(-3) and 121 individuals m(-3), respectively, with an annual mean zooplankton biomass of 129 mg m(-3). A total of 243 species of fish were sampled in the survey including many of high economic value. Three hundred and eighty-four species of benthos in 121 families were found by mud sampling and trawling. The average biomass of benthic organisms was 11.55 gm(-2), with a density of 31 individuals m(-2). Molluscs were the dominant group, followed by crustaceans; coelenterates exhibited the lowest biomass. One hundred and twenty-six species from 48 families of intertidal organisms were collected by frame sampling, with a mean annual biomass of 644.7 gm(-2) and average density of 816 individuals m(-2). The highest biomass of 1673.5 gm(-2) was collected in a coral reef region, while the highest density of 1219 individuals m(-2) occurred in a mangrove region. The coastline is characterized by coral reefs that accounts for 30% of the total coastline length in the bay, so coral reefs are a key ecosystem that are important for maintaining the regional marine resources and biodiversity. We need to pay much more attention to such diverse marine resources to maintain the integrity and function of these coastal ecosystems.