Seasonal dynamics of crustacean zooplankton community structure in Erhai Lake,a plateau lake,with reference to phytoplankton and environmental factors

The seasonal dynamics of a crustacean zooplankton community in Erhai Lake was investigated from May 2010 to April 2011. In total, 11 species were recorded, including six （6 genera） cladoceran and five （5 genera） copepod species. The crustacean zooplankton densities ranged from 24.3 to 155.4 ind./L. In winter and spring, the large-bodied cladoceran Daphnia galeata dominated the crustacean plankton community. In summer and autumn, when the colonial or filamentous algae dominated the phytoplankton communities, the small-bodied species （e.g. Bosminafatalis, Ceriodaphnia quadrangular, and Mesocyclops leuckarti） replaced the large-bodied ones. One-way ANOVA and redundancy analysis revealed that community structure was dependent upon total nitrogen, total phosphorus, water temperature, transparency, and the biomass of small algae. The variation in both phytoplankton structure and environmental variables were important factors in the seasonal succession of crustacean zooplankton structure in Erhai Lake.     

磨刀门河口在20世纪60至70年代的演变模拟与动力地貌过程分析

使用长周期动力地貌模型(long-term morphodynamic model),再现了磨刀门河口1964—1977年的演变过程,并从水动力、地形演变规律以及人类活动等角度系统分析了长周期地貌演变过程。模拟结果显示在1964—1977年磨刀门河口鹤州至交杯沙浅滩和上沟快速淤积,13a的平均淤积厚度均在40cm以上,与之相反,横洲水道杧州至大井角段和上沟东部深槽冲刷明显。磨刀门河口演变季节性特征明显。在洪季浅滩淤积,深槽冲刷;在枯季滩槽都处于淤积状态。演变过程中各种基岩岛屿使动力结构和演变规律呈现多元化,同时人类活动对整个区域的演变起到了重要的作用。     

北京市电网雷害分布规律及风险评估

根据1996—2009年北京市逐日电网灾害资料分析了北京市电网雷害的发生规律, 结果显示:北京市电网雷害存在季节变化和日变化特征。结合同期气象观测站的雷暴日资料、北京市各区县的经济和人口密度特征提出了电网雷害概率、电网雷害频度、电网雷害密度、经济易损模数和生命易损模数作为北京市电网雷害风险评估指标。在此基础上,采用4级分区法对上述电网雷害易损性评估指标进行分级,并将北京市各区县按照5个电网雷害评估指标的所属等级值累加,得到电网雷害综合易损风险评估的评估系数。结果表明:北京地区电网雷害高风险区集中在北京城区中心附近,山区和山前迎风坡地带尽管电网雷害频次较高,但电网雷害风险却相对较低。     

Long-term activity of earthquake-induced landslides: A case study from Qionghai Lake Basin,Southwest of China

Earthquake-triggered landslides are a major geological hazard in the eastern Tibetan Plateau, and have prolonged impact on earth surface processes and fluvial system. To determine how long co-seismic landslides affect basins, a massive number of landslides existing in Qionghai Lake Basin were investigated for landslide distribution characteristics and geomorphological evidences, with further comparison and analysis using historic seismic analog method. The landslides found in Qionghai Lake Basin showed clear features of seismic triggering with strongly controlled by Zemuhe fault. These landslides are still active at present. Some new slides generally occur in ancient slope failure zones causing serious secondary hazards in recent years. In this study we strengthen the idea that the landslides triggered by the 185o Xichang earthquake （Ms7.5） have long term activity and prolonged impact on the mountain disasters with a period of more than 16o years. Our results support growing evidence that coseismic landslides have a prolonged effect on secondary disasters in a basin, and invite more careful consideration of the relationship between current basin condition and landslide history for a longer period.     

Spatial spillover and the factors influencing public service supply in Sichuan province,China

This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with statistical data in 2012. The results demonstrate that expenditures on different types of public services present different spatial autocorrelation patterns. Although the spatial differences in basic public service expenditures are relatively small, a clear fan-shaped spillover to the east can be seen in Chengdu City. Chengdu also shows high clustering of advanced public service expenditures, being a typical core-periphery pattern. Post-earthquake reconstruction expenditures are clustered in the ＂5.12 Wenchuan earthquake＂ region and spill over toward cities to the east. The efficiency of public services in the mountainous areas in western Sichuan is low and exhibits a pattern of low-low spatial autocorrelation. The efficiency of public service supply is affected by economic, social, political and geographical factors. Based on the results of this analysis, we recommend a supply strategy that incorporates different types of public services and a specialized public service supply strategy for mountainous areas. Overall public service efficiency should be enhanced by focusing on narrowing the gap in farmers＇ income among regions and accelerating urbanization. Decision-makers should consider moresupportive policies with regard to providing basic public services in mountainous areas to ensure an equalized supply of basic public services. To enhance the efficiency of advanced public service supply, additional growth pole should be encouraged and incentivized; however, investments are required to drive the development of the peripheral regions through regional economic integration. Both software and hardware types of infrastructure are required to supply services efficiently during post-disaster reconstruction.     

地质资料数据服务体系建设

地质资料是地质工作成果的主要表现形式,是地质工作者智慧与劳动相结合的产物。如何对其进行有效的管理,挖掘其潜在的价值,以便更好的为社会服务,已成为地质资料信息化领域研究的一个重要课题。本文系统分析和阐述了地质资料数据服务体系建设,为地质资料数据的有效管理、应用和服务等提供参考。     

基于CIMISS的气象数据处理时效监视系统设计与实

针对气象信息网络常规运行监控业务需要,结合气象信息共享系统（China Integrated Meteorological Information Service System,简称CIMISS）的运维实际,设计开发了基于CIMISS的气象数据处理时效监视系统,实现了对13类上行气象观测数据处理主要的节点时效、自动站疑误数据处理、数据访问服务性能的实时监控,并可为部分气象观测设备的运维保障提供参考指引。文中从系统结构与数据流程、主要业务功能、技术实现等方面对系统的实现方式等进行了介绍。     

无人飞行器遥感影像的自动相对定向研究

提出一套适合于无人飞行器遥感影像的全自动相对定向流程。其技术要点主要包括：利用SIFT特征的旋转、微小仿射的不变性等从影像提取特征并匹配,基于RANSAC的相对定向进行误匹配剔除,划分均匀网格的Frstner特征提取,基于核线约束的近似一维影像匹配,最小二乘匹配。试验结果表明,该方法具有较高的匹配成功率,获得点数多且点位分布均匀,具有较高的精度。     

对测绘成果档案管理工作的思考

测绘成果档案是各级测绘部门在测绘工作中形成的具有保存价值的基础测绘成果,成果管理工作具有非常重要的意义。随着现代科学技术的发展,电子数据逐步被数字测绘成果所取代,因此对测绘成果档案的管理提出了新的要求。目前测绘成果档案管理存在诸多问题。本文在分析这些问题的基础上提出当前测绘成果档案工作管理对策。     

台风眼壁的云结构与降水形成机制分析

使用带有详细微物理过程的ARPS模式,对台风韦帕（Wipha）进行三重嵌套细网格模拟,利用模式结果,对台风眼壁强降水中心的云结构和降水形成机制进行分析,结果表明：冰相微物理过程是启动和形成台风眼壁暴雨的主要降水形成机制。在9000～14000 m高空,云水在很低的温度下经均质核化产生冰晶,或经非均质核化形成云冰;冰晶通过凝华增长（psfi,贝吉龙过程）、雨水收集云冰产生雪（praci）和冰晶粘附雨水成雪（piacr）过程生长为雪;霰产生主要包括4个过程：冰晶接触雨水使其成霰（piacr）、雪撞冻云水使其成霰（psacr）、雨水收集云冰转化成霰（praci）或雨水冻结为霰（pgfr）;霰粒子通过收集云冰干增长（dgaci）,霰撞冻云滴增长（dgacw）等过程生长;霰融化（pgmlt）和雪融化（psmlt）成雨水后再通过碰并云水等暖云生长过程,最后形成雨水。霰过程的强弱在雨水形成机制中很重要。（29.5°N、121.8°E）和（28.3°N、120.4°E）强降水中心冰晶转化率没有太大差别,但是（29.5°N、121.8°E）强降水中心上空冰晶通过贝吉龙过程快速成长为雪和霰,霰粒子增长过程远远强于（28.3°N、120.4°E）强降水中心,低空又有较高的云水转化率,使降水粒子在暖云中继续快速生长,冷暖云过程的有利配置使（29.5°N、121.8°E）出现较强雨水转化率。