Post-earthquake building damage assessment in Yushu using airborne SAR imagery          下载免费PDF全文

Dingjian Jin  Xiaoqing Wang  Aixia Dou  Yanfang Dong 《地震科学（英文版）》2011,24(5):463-473

The synthetic aperture radar (SAR) plays an important role in earthquake emergency response because of its all-time and all-weather imaging capabilities. On April 14, 2010, an MS7.1 earthquake occurred in Yushu county, Qinghai province of China, causing a lot of buildings collapsed. In this paper, the building damage in Yushu city due to the earthquake was assessed quantitatively using high-resolution X-band airborne SAR image. The features of the buildings with different damage levels (collapsed, partial collapsed, non-collapsed) in the SAR image were analyzed first. Based on these building features, we interpreted the individual building damage in Yushu city block by block and got the numbers of the collapsed, partial collapsed and non-collapsed buildings separately for each block, referring to pre-earthquake QuickBird image when necessary. Let the damage index of individual collapsed, partial collapsed, non-collapsed building be 1, 0.5, 0 respectively, the remote sensing damage index of each block was then calculated through remote sensing damage index equation. Finally, the preliminary quantitative relationship between the remote sensing damage index interpreted from the SAR image and that interpreted from the optical image was built up. It can be concluded that a desirable damage assessment result can be derived from high-resolution airborne SAR imagery.  相似文献   

基于遗传算法和BP神经网络的矿井涌水量预测   总被引：2，自引：0，他引：2  

窦贤明  杨永国  徐伟伟  靖凤伟 《中国煤炭地质》2009,(10):37-38

为避免BP神经网络极易陷人局部解的问题,针对遗传算法具有全局寻优的特点,提出了用遗传算法优化BP神经网络预测方法,并以刘桥二矿为例,对其矿井涌水量进行了预测。首先选取刘桥二矿区的2005年3月至2006年12月的矿井涌水量数据进行分析,然后使用遗传算法优化BP网络的初始权值和阈值,最后使用BP神经网络进行训练。将其成果与纯BP网络算法进行比较,结果表明：遗传算法优化BP神经网络的预测方法的预测精度高于纯BP网络算法,将其应用于矿井涌水量预测是有效可行的。  相似文献   

立体雷达方法在星载测雨雷达上的应用   总被引：5，自引：0，他引：5  

窦贤康  J.Testud 《气象学报》1999,57(3):358-366

星载测雨雷达的应用,必须满足一些主要条件：高的空间分辨率、宽阔的覆盖范围、大的动态降雨测量范围以及精确的点测量等。由于技术条件的限制,满足这些条件的雷达工作在被雨衰减的频率段,因此必须修正由于衰减所导致的误差。立体雷达方法利用雷达从两个不同角度对雨团的观测来进行衰减效应的订正并实现整个观察区域的雷达反射率因子和比衰减因子场的反演。通过数值实验研究了星载特性的引入造成的不均匀性束内填充效应对立体雷达方法的影响  相似文献   

Origins of heavy oils in the Erlian Basin, ne China     

Lirong Dou  Yuheng Zhu  Tao Yang  Shubao Xu  Xuecong Ping 《Marine and Petroleum Geology》1998,15(8):222

The Erlian Basin is located in the Central Asia-Mongolian fold belt between the Siberian and Sino-Korean Cratons. It is a Mesozoic continental rift basin composed of 52 individual fault-depressions. The main phase of rifting took place during the Early Cretaceous when a series of fluvial-lacustrine sediments were deposited. Each depression forms an independent sedimentary system and behaves as an independent petroleum system. Hydrocarbon source rocks are found in the upper Arshan and lower Tengger Formations. These are mainly type II source rocks and are mainly located in oil generation window at the present day. A series of oilfields and commercial oil flows have been found in the basin, highlighting its good petroleum potential. Many of these oils are heavy.Six oil samples from the Anan and ten from the Jirgalangtu Depressions have been subjected to routine geochemical analytical techniques in order to evaluate the origins. The methods used include gas chromatography of the saturated and aromatic hydrocarbon fractions, gas-chromatography-mass-spectrometry of the saturated hydrocarbon fraction and stable carbon isotope analyses. The trace metal elements of the biodegraded oils from the Jirgalangtu Depression were also analysed by atomic absorption spectroscopy.Two types of heavy oils : primary and biodegraded were identified on the basis of these data. The former includes both immature and mature heavy oils. A filtering-and-spill process was proposed to explain the origin of primary mature heavy oils (or tar-mat) in the Anan Depression. The biodegraded oils from the Jirgalangtu Depression were ranked and classified in terms of the degree of biodegradation, using a series of geochemical parameters based on the gas chromatographic concentrations and biomarker fingerprints of gas-chromatography-mass-spectrometry of the saturated hydrocarbon fraction. The relationship between oil saturation and porosity indicates that the heavy oils in the Jirgalangtu Depression were biodegraded after they accumulated.  相似文献   

日较差分级的北京地面逐时气温预报   总被引：9，自引：1，他引：8  

张德山  窦以文  白钢  王金英 《气象》1999,25(5):54-57

统计了不同日较差等级与其相应等级内的逐时气温的气候平均值及逐时气温变量气候平均值,在此基础上客观自动地计算出北京区域的分片逐时气温预报值,由此次生出与气温变化有关的专业气象预报产品,应用于专业气象业务。  相似文献   

郁江南宁段致洪气象特征分析     

吴兴国  杨望月  黄治逢  窦淑琴  吕学成  梁树养 《气象研究与应用》1999,20(4)

郁江南宁段致洪气象特征的分析表明,热带气旋影响左、右江流域是致洪的主要原因;洪峰出现前的第9到第5天的流域降雨量对洪水的形成具有最重要的作用.  相似文献   

龙感湖水生植被   总被引：10，自引：0，他引：10  

张圣照  窦鸿身  姜加虎 《湖泊科学》1996,8(2):161-168

于１９９３年９月对龙感湖水生植被及环境进行了调查研究。龙感湖有水生植物２６科３８属５０种,依据优势种群划分９个群丛,其分布面积２８３．５ｋｍ＾２,占全湖总面积的８９．７％,植被现有年生产力达２１４７７３０ｔ,对渔业生产和生态环境具有十分重要的意义。建议对该湖植被应合理开发利用,如果围网养鱼得到广泛地发展,渔业生产潜力每年可达４１８１．８ｔ。  相似文献   

Reconstruction of autumn sea ice extent changes since AD1289 in the Barents-Kara Sea,Arctic     

Qi Zhang  Cunde Xiao  Minghu Ding  Tingfeng Dou 《中国科学:地球科学(英文版)》2018,61(9):1279-1291

Using high-resolution ice core and tree ring proxies for sea ice extent(SIE), we reconstructed a robust time series of autumn SIE over the Barents-Kara(B-K) sector of the Arctic from AD1289–1993. After intercomparing the results and statistical parameters using the ordinary least squares regression(OLSR), the principle component regression(PCR) and the partial least squares regression(PLSR) methods, SIE time series were synthesized into a more robust series using the weighted average method, which used the explained variances as weights. The results showed that from the end of the 13 th century to the end of18 th century, the autumn B-K SIE was large, with large variations and a slightly expanding trend overall. This reflected significant multidecadal oscillations under the Little Ice Age(LIA) background. The B-K SIE began to decrease at the end of the18 th century, and a shrinking trend became significant during the second half of the 19 th century, which lasted into the 1930 s–1940 s. The 1930 s–1940 s was a period with a relatively low SIE in the B-K Sea, and the SIE had a short period of expansion from the 1940 s–1970 s. However, the B-K SIE has continuously and significantly shrank since the 1970 s. The reduction in the B-K SIE since the end of the 18 th century has been unprecedented in both duration and speed over the last 700 years. The B-K SIE has retreated significantly since the 1970 s, with a speed 6.18 times greater than the former mean retreating speed. The industrial revolution may be a dominant factor in this result. The Arctic SIE in recent years may be the lowest it has been over the last millennium.  相似文献   

基于蒙特卡洛方法的地震目录模拟及相符性检验——以汾渭地震带为例     

邵霄怡  王晓青  窦爱霞  袁小祥 《中国地震》2018,34(1):35-47

人工地震目录模拟是改进现有地震目录不完备性、弥补大地震记录稀缺,以及完善地震学相关研究的有效途径之一。本文基于地震活动的泊松分布模型、古登堡-里克特震级-频度关系,利用能较逼真描述具有随机性质事物特点及物理实验过程的蒙特卡洛方法,模拟汾渭地震带未来30、50、100年等不同时长的地震目录,并对其进行统计检验。分析表明,模拟地震目录符合设定的地震活动性参数和泊松分布假设特征。依据模拟地震目录,对未来该区域地震趋势进行了分析,以期为地震危险性分析提供参考。  相似文献   

瞬变电磁法深度探测正演模拟研究     

胡代明  窦立婷 《地震地磁观测与研究》2018,39(3):69-75

针对当前瞬变电磁法探测能力有限的问题,利用一次磁场理论公式,分析相同磁矩下、不同发射线圈一次磁场分布及衰减规律,从而确定其信号深度影响范围;对水平层状介质相同磁矩下、不同发射线圈的二次场进行数值模拟,采用Guptasarma和Singh滤波算法及余弦变换法,利用均匀半空间解析公式进行验证,并对不同正演模型结果进行分析,总结发射磁矩决定探测深度大小。对磁矩相同条件下产生的结果数据进行拟合,得出有效探测深度与线圈边长2倍相当的结论,可为野外矿井生产与工程勘探提供施工布置与定量解释的指导依据,从而提高野外工作效率。  相似文献