云南盐津2006地震群的强震动应急观测研究

2006年7月22日09时10分21.6秒,云南省昭通市盐津县境内(28°01′N,104°08′E)发生Ms5.1地震,震源深度9km.极震区烈度为Ⅵ度,个别Ⅶ破坏点,等震线形状呈椭圆形,长轴走向北东向.地震造成22人死亡,13人重伤,35428户、151168人受灾.2006年8月25日13时51分41.1秒,盐津县(28°03′N,104°07′E)再次发生5.1级地震,震源深度7km,较7月22日地震略浅.微观震中由722地震位置向西北偏移约4km.由于震中位置基本相同,故地震灾害相互叠加,出现灾害加重现象和灾情范围扩大趋势,地震造成2人死亡,重伤7人,1万多户、4.5万多人需要紧急转移安置,房屋倒塌1500多间,其中170所学校的校舍不同程度受损.     

Evaluating the accuracy of Chinese pasture data in global historical land use datasets

Global historical land use datasets are widely used in global environmental change studies; however, uncertainties in the included pasture data have not been evaluated. In this study, using trend, relative difference ratio(RDR), and spatial comparisons, we evaluated the accuracy of China pasture data in the HYDE(versions 3.1 and 3.2), SAGE, and PJ datasets using historical document-based reconstructions, including the land use datasets for China covering 1935–1997(hereafter Ge-dataset)and Northeast China covering the 1700 s–2000(hereafter Ye-dataset), and the satellite-based China's Land-Use/cover Datasets(CLUDs) for 1980–2015. Four important results were obtained.(1) China pasture area in the HYDE, SAGE, and PJ datasets and grassland area in the Ge-dataset, Ye-dataset, and CLUDs show both disparate trends and large differences in absolute values.(2)Spatially, 50.9%, 52.8%, and 63.0% pasture/grassland grids in 2000 had RDRs greater than 60% between HYDE3.1, HYDE3.2,and SAGE datasets, and CLUDs, respectively. The percentage of grids with RDRs less than 20% were 24.9%, 26.7%, and 16.0%,respectively.(3) Based on HYDE3.2, the spatial distribution of pasture in Northeast China over the last 300 year has expanded,which is in contrast to the results from the Ye-dataset, which shows the spatial distribution of grassland shrinking because of human reclamation activities.(4) The large contrasts between the global datasets and Chinese native datasets are due to differences in pasture/grassland definitions, land use practices, and spatial reconstruction methods.     

Ecological Security Assessment of the G20 and its Drivers: EF-Path-STIRPAT Modeling

Natural Resources Research - Because of the increasing global attention being given to ecological security, the need to identify and quantify its underlying causes has sparked heated debate....     

基于GPS观测分析青岛地区电离层板厚变化特性

基于青岛站2000年8月至2006年4月间半个太阳活动周的GPS和测高仪的同步观测,提取期间的电离层TEC和f_oF_2的小时观测数据,联合分析该地区电离层板厚的日变化、季节变化和随太阳活动变化,研究表明青岛地区电离层板厚在日出前时段出现明显的增强峰,并随季节和太阳活动呈现出较复杂的变化关系.利用板厚的相对偏差,探讨了电离层板厚扰动变化分布特征.     

移动式三维激光扫描仪在地下管廊测量中的应用

针对传统地下管廊测量方法中存在的作业效率低、精度差等问题,笔者试验了一种基于移动手持扫描技术的地下管廊测量新方法。本文以济南市福地街旁某地下管廊为例,制定了可行的测量方案,通过GEOSLAM ZEB-REVO移动式三维激光扫描仪获取点云数据,采用Trimble Realworks软件进行数据后处理,并与全站仪测量结果进行对比分析。结果表明,移动式三维激光扫描仪在地下管廊测量中可以明显提高作业效率且满足测量精度要求,具有较好的应用前景。     

基于Encoder-Decoder网络的遥感影像道路提取方法

针对道路目标特点,设计实现了用于遥感影像道路提取的Encoder-Decoder深度语义分割网络。首先,针对道路目标局部特征丰富、语义特征较为简单的特点,设计了较浅深度、分辨率较高的Encoder-Decoder网络结构,提高了分割网络的细节表示能力。其次,针对遥感影像中道路目标所占像素比例较小的特点,改进了二分类交叉熵损失函数,解决了网络训练中正负样本严重失衡的问题。在大型道路提取数据集上的试验表明,所提方法召回率、精度和F1-score指标分别达到了83.9%、82.5%及82.9%,能够完整准确地提取遥感影像中的道路目标。所设计的Encoder-Decoder网络性能优良,且不需人工设计提取特征,因而具有良好的应用前景。     

江苏80m高度风能评估方法探讨

80 m轮毂高度风能评估关键问题之一是风随高度的变化规律研究,目前以最小二乘法、常规常参数方法最具代表性,但两者对高空风能的评估结论差异可能较大.使用幂常数指数方案,江苏省80 m高空陆上风能储量达到7.39×1010 W,可开发量为0.59×1010 W,而使用最新的最小二乘技术对江苏省80 m高空风能评估表明,陆上风能储量达到13.54×1010 W,可开发能量为1.07×1010 W,全省陆上和近海的可开发风能储量可达到4.29×1010 W,约为常规常参数方法计算结果的1.8倍.两种高空风能的评价结果均表明,江苏省风能资源丰富,沿海地区和近海具有巨大的风能储量,有很大的开发利用前景.     

2002年夏季东亚地区环流20—30 d主振荡型延伸期预报研究

用2002年3-9月逐日东亚地区850 hPa经向风场资料建立主振荡预测模型(POP),对影响长江下游地区强降水过程的主要低频经向风场(20-30 d时间尺度)的时空变化进行10-30 d延伸期独立预报试验.试验结果表明,在夏半年135次预测中提前20 d预报的相关预报技巧在0.50以上,很好地预报了夏季3次强降水过程对应的经向风的低频变化过程.对20-30 d振荡显著的多年资料预报试验表明,这些预测模型是预报低频环流时空演变的有效工具,对于提高未来3-4周长江下游强降水过程的预报准确率有重要意义.     

河南宝丰气象因子与烤烟DNA甲基化关系分析

通过建立宝丰气象因子与烤烟烟叶DNA甲基化的数学模型,找出影响宝丰烟叶DNA甲基化的主要气象因子,为研究宝丰烟叶品质和风格的形成提供一种方法.以灰色关联分析筛选出对DNA甲基化影响大的4个气象因子为自变量,把DNA甲基化作为因变量,建立修正的Logistic数学模型并进行分析.结果表明,单因子对DNA甲基化影响程度依次...     

Different Relationships Between Spring SST in the Indian and Pacific Oceans and Summer Precipitation in China

Observational and reanalysis data are used to investigate the different relationships between boreal spring sea surface temperature （SST） in the Indian and Pacific oceans and summer precipitation in China. Partial correlation analysis reveals that the effects of spring Indian Ocean SST （IO SST） and Pacific SST （PSST） anomalies on summer precipitation in China are qualitatively opposite. When IO SST anomalies are considered independently of PSST anomalies, precipitation decreases south of the Yangtze River, in most areas of Inner Mongolia, and in some parts of Liaoning Province, and increases in the Yangtze River valley, parts of southwestern and northern China, northeastern Inner Mongolia, and Heilongjiang Province. This results in a negative-positive-negative-positive pattern of precipitation anomalies in China from south to north. When PSST anomalies （particularly those in the Nin o3.4 region） are considered independently of IO SST anomalies, the pattern of precipitation anomalies in China is positive-negative-positive-negative from south to north. The genesis of summer precipitation anomalies in China is also examined when El Nin o-Southern Oscillation （ENSO） signals are removed from the ocean and atmosphere. An anticyclonic low-level wind anomaly forms in the South China Sea-Northwest Pacific area when the IO SST anomaly （SSTA） is warm and the Northwest Pacific SSTA is cold. This anticyclonic anomaly substantially influences summer precipitation in China. Anomalous warming of tropical IO SST induces positive geopotential height anomalies in the subtropics and an east-west dipole pattern in midlatitudes over Asia. These anomalies also affect summer precipitation in China.