POTENTIAL PREDICTABILITY OF MONTHLY PRECIPITATION OVER CHINA          下载免费PDF全文

柳艳菊  马开玉  林振山 《Acta Meteorologica Sinica》2000,(3)

In this paper,based on the data at 70 stations selected evenly over China for 31 years from1961—1991.three methods to estimate climatic noise have been discussed and then the climaticnoise and potential predictability of monthly precipitation(January.July.April and October)havebeen examined.The estimating of climatic noise is based on the method of Madden and improvedmethods of Trenberth and Yamamoto et al.(1985).The potential predictability is approximatedby the ratio of the estimated interannual variation to the natural variation.Generally.the climaticnoise of monthly precipitation over China has obvious seasonal variation and it is greater in summerthan in winter,a bit greater in autumn than in spring.In most areas,the climatic noise isprominently decreasing from south to north and from coast to inland.The potential predictabilityof monthly precipitation also has obvious seasonal and regional difference,but the potentialpredictability is greater in winter than in summer in most parts of China.Whereas the comparisonof spring and autumn is not obvious.Comparing with the method of Madden,the estimated valuesof climatic noise based on the improved methods of Trenberth and Yamamoto et al.are relativelylower.  相似文献   

State-of-the-art of geotechnical earthquake engineering practice     

W. D. L. Finn   《Soil Dynamics and Earthquake Engineering》2000,20(1-4)

Major developments in geotechnical earthquake engineering practice over the last 15 years are reviewed. The objectives of the review are to present a coherent view of the current state of practice at the highest level and to examine trends, which may shape practice in the future. Developments are described in the following areas: specification of design ground motions, dynamic response analysis, evaluation of liquefaction potential, evaluation of residual strength of liquefied soil, post-liquefaction displacement analysis, and seismic risk analysis.  相似文献   

Discussion on Principles and Methods in Estimating the Maximum Potential Earthquakes in Low Seismicity Areas     

Chen Jiageng  Yan Jiaquan  Xu Guangyin  Hao Yuqin 《中国地震研究》2000,14(2):188-198

Five principles and methods are proposed for estimating the maximum potential earthquakesin low seismicity areas,and their applicabilities are discussed,taking Sichuan basin as asample area.The proposed principles and methods are not only on the grounds of thegeological tectonics but also considered fully the mutual complementation between geologicaland seismological methods.They will be helpful to the study of engineering seismology andthe assessment of designing ground motion parameters in low seismicity areas.  相似文献   

德化—尤溪地区金矿潜在资源量初步估算     

连天萍 《福建地质》2000,(3)

德化—尤溪地区是福建省重要的金矿成矿区。通过综合成矿信息提取、筛选出与金矿成矿作用密切相关的成矿信息标志 ,应用信息量计算法、特征分析法 ,优选出金矿找矿靶区 10处 ,其中 A类 2处 ,B类 2处和 C类 6处。在优选出的找矿靶区内 ,采用一元线性回归分析法和蒙特卡洛法模拟概率分布曲线 ,分别估算出该区金矿潜在资源量分别为 91.3t和 96 .7t  相似文献   

"西气东输"工程沿线煤层气资源开发潜力评价   总被引：1，自引：0，他引：1  

吴建光  张延庆  张遂安  叶建平 《煤田地质与勘探》2000,28(6):27-29

“西气东输”工程经过多个大型煤层气田,总资源量近１０万亿ｍ＾３,相当于塔里木盆地的天然气资源量,工程沿线的沁水,鄂尔多斯盆地是我国煤层气勘探开发的重点区域,已经取得了煤层气产气量的突破。“西气东输”工程的实施,为勘探开发煤层气创造了管网条件。  相似文献   

Logistic回归联合ROC曲线模型在雷电潜势预报中的应用          下载免费PDF全文

吴安坤  郭军成  黄天福 《中低纬山地气象》2022,46(2):88-92

利用贵阳站2020年1-10月逐日探空资料和闪电监测资料,逐一选取72个物理量参数纳入单因素逻辑回归,筛选具有显著性统计学意义（P＜0.001）的指标进入多因素逻辑回归模型,选取满足检验条件P＜0.05的参数得到雷电潜势预报模型,通过logistic回归联合ROC曲线模型开展雷电潜势预报研究。结果表明：①多因素逻辑回归模型预警效果优于单因素模型,预警准确度从75.4%提高到79.5%;②联合ROC曲线确定预报模型的概率阈值为0.611,雷电潜势预报的命中率POD为84.01%％,虚假警报率FAR为26.05%,临界成功指数CSI为69.38%,准确率较高,雷电潜势预报具有较好的预报能力;③Logistic回归模型联合ROC曲线法在气象预测预报,特别是非线性预测中有一定的应用价值。  相似文献   

柽柳属植物抗旱性能研究及其应用潜力评价   总被引：46，自引：19，他引：27  

张道远  尹林克  潘伯荣 《中国沙漠》2003,23(3):252-256

柽柳属植物普遍具抗旱性能,以沙生柽柳为最强。作者从生物生态学特性、水分生理状况及抗水分胁迫的生理机制3方面系统地探讨了柽柳属植物抗旱机制。柽柳叶、营养枝及根、茎的解剖结构均表明,柽柳已形成了一系列适应于干旱环境的旱性器官。柽柳抗旱性能越强,则水势越低,持水力越强。当缓慢水分胁迫时,柽柳体内有脯氨酸、可溶性糖、K⁺、Na⁺的主动积累,共同参与渗透调节。对柽柳抗旱性能的应用潜力进行了评价,指出柽柳是优良防风固沙树种,其柽柳包的"年轮"对揭示当时的生态环境及荒漠环境演变有一定的指示作用。仅分布于流沙地区的沙生柽柳可作为沙漠中的"水源标记"。柽柳具优良的抗逆基因,通过基因工程克隆柽柳抗逆基因并转移到作物和牧草中,必将在维护生态安全、改造生态环境的同时,获得显著的经济效益。  相似文献   

科尔沁沙地奈曼旗近5年来风况及合成输沙势   总被引：21，自引：13，他引：8  

张华  李锋瑞  李玉霖  伏乾科 《中国沙漠》2004,24(5):623-627

应用奈曼沙漠化研究站1998-2002年的气象资料, 统计分析了奈曼旗近5a来的风况特征和输沙势。结果表明: ①研究区3~5月起沙风发生频数最高, 占全年起沙风的38%~58%; 平均风速和最大风速值最大, 分别为6.0~7.5m·s^-1和9.5~16.9m·s^-1。该风况特征与地表冻融、裸露、干旱疏松相耦合, 形成了区内的风沙活动期。②在风沙活动期内, 风环境基本为锐双峰风况, 西北风居主导地位, 频数占54%; 南风和西南风次之, 频数占38%。③在风沙活动期内, 研究区属于高风能环境, 合成输沙势RDP为66.3VU(风速以m·s^-1为单位), 合成输沙方向RDD为ESE113°。  相似文献   

广西霜日的气候变化特征及其与500 hPa位势高度的关系     

涂方旭  董蕙青  李雄 《气象研究与应用》2000,21(1):15-17

在统计广西各站历年霜日总数、初霜、终霜日的基础上 ,分析了广西霜日的气候概况、气候变化特征及与 5 0 0 h Pa位势高度的关系。  相似文献   

TECTONIC FEATURES AND HYDROCARBON POTENTIAL OF THE EASTERN QAIDAM BASIN     

Yang Minghui  Liu ChiyangWT  ”BX 《地学前缘》2000,(Z1)

TECTONIC FEATURES AND HYDROCARBON POTENTIAL OF THE EASTERN QAIDAM BASIN  相似文献