似大地水准面的支持向量机模型研究     

郝伟涛  郭向前  米川 《测绘科学》2012,(4):22-23,63

支持向量机(SVM)是一种基于结构风险最小化原理的学习技术,也是一种新的具有较好泛化性能的回归方法。本文简要介绍了SVM原理,针对大面积复杂似大地水准面的确定问题,仅依据测区的GPS水准实测数据,利用SVM方法整体建模。通过工程实例并与神经网络模型进行对比,证实了SVM似大地水准面模型的可靠性。  相似文献   

Hindcast skill and predictability for precipitation and two-meter air temperature anomalies in global circulation models over the Southeast United States     

Lydia Stefanova  Vasubandhu Misra  James J. O’Brien  Eric P. Chassignet  Saji Hameed 《Climate Dynamics》2012,38(1-2):161-173

This paper presents an assessment of the seasonal prediction skill of current global circulation models, with a focus on the two-meter air temperature and precipitation over the Southeast United States. The model seasonal hindcasts are analyzed using measures of potential predictability, anomaly correlation, Brier skill score, and Gerrity skill score. The systematic differences in prediction skill of coupled ocean–atmosphere models versus models using prescribed (either observed or predicted) sea surface temperatures (SSTs) are documented. It is found that the predictability and the hindcast skill of the models vary seasonally and spatially. The largest potential predictability (signal-to-noise ratio) of precipitation anywhere in the United States is found in the Southeast in the spring and winter seasons. The maxima in the potential predictability of two-meter air temperature, however, reside outside the Southeast in all seasons. The largest deterministic hindcast skill over the Southeast is found in wintertime precipitation. At the same time, the boreal winter two-meter air temperature hindcasts have the smallest skill. The large wintertime precipitation skill, the lack of corresponding two-meter air temperature hindcast skill, and a lack of precipitation skill in any other season are features common to all three types of models (atmospheric models forced with observed SSTs, atmospheric models forced with predicted SSTs, and coupled ocean–atmosphere models). Atmospheric models with observed SST forcing demonstrate a moderate skill in hindcasting spring-and summertime two-meter air temperature anomalies, whereas coupled models and atmospheric models forced with predicted SSTs lack similar skill. Probabilistic and categorical hindcasts mirror the deterministic findings, i.e., there is very high skill for winter precipitation and none for summer precipitation. When skillful, the models are conservative, such that low-probability hindcasts tend to be overestimates, whereas high-probability hindcasts tend to be underestimates.  相似文献   

小江断裂带巧家段巨型古滑坡及其工程地质特征     

冯振  吴中海  曹佳文  胡萌萌  哈广浩  康怀信 《地球学报》2019,40(4):629-636

巧家地处小江断裂带与则木河断裂、五莲峰断裂相交地带, 地质构造复杂, 断裂与地震活动频繁, 崩滑流地质灾害极为发育。通过遥感解译与工程地质分析, 在小江断裂带巧家段东侧识别出一处巨型古滑坡。巧家古滑坡平面形态为筲箕形, 堆积体长5.5 km, 宽9 km, 平均厚度约250 m, 预测体积达到约 10亿m3。古滑坡后缘为典型的圈椅状地貌, 两侧边界多沿基岩地层中的次级断层发育, 并在地表呈阶梯式的台阶状地形。堆积体的岩性主要由二叠系阳新组灰岩组成, 局部存在二叠系峨眉山组玄武岩, 多具碎裂-松散结构。整体上看, 该滑坡体风化强烈, 中前部发育大型纵向冲沟, 暗示形成时代较老。综合分析认为, 巧家古滑坡成因极可能是由于小江断裂带强烈左旋走滑作用下, 导致巧家东侧山地发生持续性的构造抬升, 并在巨大地震活动触发下形成。关于小江断裂带巧家段在未来的大地震活动背景下, 是否可能导致古巨型滑坡复活, 或该区是否还存在发生类似巨型地震滑坡的风险等问题, 显然值得进一步深入研究。  相似文献   

防震减灾行政法律关系问题探讨   总被引：1，自引：1，他引：0  

哈辉 《高原地震》2003,15(4):52-57

运用行政法学基本原理,结合防震减灾法律、法规和工作实际,分析探讨了防震减灾行政法律关系中的主体、客体等问题。  相似文献   

昆仑山口西8.1级地震应急工作概况及震后有关问题的思考     

哈辉 《高原地震》2002,14(1):11-16

从震害损失评估、震后监测预报、初步科学考察、震后社会对策等几方面，对昆仑山口西8．1级地震应急工作进行了概述。通过对加强青藏构造块体及其边缘地区的地震监测预测及防震减灾工作紧迫性、重要性的分析，提出了震后工作设想和措施。  相似文献   

依靠科学技术进步全面推动防震减灾工作--青海省地震局(队)成立30年科技工作回顾     

哈辉  刘海宽  裴丽萍 《高原地震》2002,14(4):9-17

对青海省地震局(青海省地震队)成立30年来防震减灾科学技术工作取得的主要进展进行了简要回顾，对今后工作要点进行了初步分析。  相似文献   

青海盐湖集团一期工程采卤现状综述及可持续发展探讨   总被引：1，自引：0，他引：1       下载免费PDF全文

杨廷敖  哈占芳  张跃东 《盐湖研究》2005,13(3):46-51

综合论述了青海盐湖集团一期工程采卤生产现状及存在问题,提出了一种“转卤补水溶钾”的盐湖补水方式,以引导盐田生产持续发展。  相似文献   

2002年3月21—22日影响韩国的沙尘天气分析          下载免费PDF全文

金正润  牛生杰  河惠卿 《大气科学学报》2007,30(5):643-647

利用气象卫星、天气形势场和NCEP/NCAR再分析资料,分析了2002年3月21—22日影响韩国沙尘天气的原因。结果表明:影响韩国沙尘天气的沙尘主要源地是蒙古国和中国内蒙古地区。沙尘天气发生在地面冷锋后部,高压伸展的前面;19日和20日沙尘暴发生后,沙尘沿着西北风输送,21日早晨影响韩国;PM10最高值达到2 778.2μg/m³,由于西北风较强,沙尘暴发生后很快影响到韩国,但在韩国持续的时间较短。  相似文献   

地理空间信息应急保障供应链研究     

哈长亮  姜坚  王宝  李加群  郭立群 《测绘与空间地理信息》2018,(2):152-153,156

在卫星影像制作的DOM和DEM基础上,利用侦查无人机拍摄的影像照片,在DOM底图上计算目标的精确坐标和对DLG数据进行及时更新,满足了应急保障需要。  相似文献   

Application of gravity and magnetic methods for the crustal study and delineating associated ores in the western limb of Hazara Kashmir Syntaxis,Northwest Himalayas,Pakistan     

Muhammad Rustam Khan  Shahid Saleem Bilali  Fahad Hameed  Awais Rabnawaz  Sohail Mustafa  Naveed Azad  Muhammad Basharat  Abrar Niaz 《Arabian Journal of Geosciences》2018,11(6):131

The present geophysical study deals with the ores and crustal demonstration of southeastern Hazara and its adjoining areas of Azad Jammu and Kashmir, Pakistan, on the basis of terrestrial gravity and magnetic data. Tectonically, the study area lies in the Lesser Himalayas as well as to an extent in the sub-Himalaya, more specifically in the western limb of Hazara Kashmir Syntaxis. In this study, 567 gravity and 508 magnetic stations have been measured with CG-5 gravimeter and proton precession magnetometer, respectively. The collected data have been processed by applying standard corrections and then different types of maps were prepared. The ores in the area have been delineated by the qualitative interpretation of residual Bouguer anomaly and reduction to pole total magnetic intensity maps, whereas regional structures are demarcated by the Bouguer anomaly and regional Bouguer anomaly maps. The positive contour closures on the residual Bouguer anomaly map indicate the iron ore and phosphate, whereas negative contour closures are the effects of low-density material which consists of gypsum and soapstone. The pole-reduced total intensity map also shows the negative and positive contour closures almost in the same localities and confirms the residual Bouguer anomaly map. The geological model computed on the basis of Bouguer anomaly demarcated a series of faults between different rock units in the study area. The Kashmir Boundary Thrust cuts the western limb of Hazara Kashmir Syntaxis near the apex in the north of Muzaffarabad and marks the boundary between Murree Formation and carbonates of Abbottabad Formation. The gravity model also suggests that the thickness of the crust increases towards the northeast.  相似文献