重投影技术在专题地图转绘中的应用

在高斯投影地形图和墨卡托投影专题图之间转换,地形图资料进行专题地图编绘作业时,首先把高斯投影坐标转换到以地理坐标为基础的统一地理框架,然后把地理坐标转换为墨卡托投影坐标,最终建立起地形图与专题地图之间的共同控制基础.通过计算验证,与在专题地图上加绘高斯公里网并进行套合转绘的传统方法相比,具有较高精度,能更好地满足转绘工...     

雷电监测产品与潜势预报在抗震救灾中的运用

“5．12”汶川大地震后,由于地震灾区处于多雷区,并且正处于一年中雷电频发时段,救援及重建工作都需要参考雷电产品来开展。针对抗震救灾以及灾后重建的特殊需求,调整雷电监测预警预报平台的内部参数及统计指标,及时制作和发布地震灾区雷电潜势预报、短时临近预警产品和实时雷电活动监测快报。保障了灾民临时安置点避免雷电带来的次生灾害,并为抗震救灾的军、民运输飞机提供了航空气象保障,以及为灾后临时安置房建设提供了大量的雷电统计数据,为灾后重建工作做出了贡献。通过对用户的服务,四川省雷电监测产品与潜势预报在抗震救灾中的运用具有较好的借鉴作用和推广价值。     

地形横向密度扰动对于区域大地水准面建模的影响

分别利用Helmert和KTH法模拟试算了不同地形起伏区域内横向密度扰动对于大地水准面的影响。结果表明,在地形起伏较小的平原或丘陵地带,横向密度扰动的影响一般不会超过cm级,在精度允许的范围内可以忽略其影响;在地形起伏较大的山区,横向密度扰动的影响可达cm甚至dm级,对于cm级大地水准面精化而言,需要考虑其影响。此外,基于Helmert与KTH法解算的结果在地形起伏剧烈的山区差异较大,由于Helmert法计算地形效应时忽略了外区地形质量的影响,其解算结果可能存在偏差。总体而言,在地形起伏剧烈的山区建模时,需利用多种计算方法基于实测数据分别进行试算,通过计算的变密度大地水准面与实测的GPS水准数据进行比较分析,得到适合该区域的大地水准面建模方法。     

纪念邢台地震30周年

文章回顾了当年邢台人民在常中央和全国人民的关怀支援下，以自力更生、艰苦奋斗的精神抗震救灾、恢复家园的豪壮历史，并热情地介绍了３０年来邢台人民取得的伟大成就，谨以此纪念邢台地震３０周年。     

中高山区高精度航磁视磁化强度填图方法

利用GPS高度和DTM高度数据,通过地形等效变换方法进行中高山区视磁化强度填图,避开了目前还不太有效的曲面地形改正方法问题,获得了精度较高的视磁化强度反演结果．这种适合于起伏地形、起伏测量面的视磁化强度填图方法为今后中高山地区航磁异常解释提供了一个可行的方法和解决问题的新思路．本文给出了中高山区起伏观测面下航磁资料的无负值视磁化强度填图方法,并通过模型和实际资料处理验证了这种方法的正确性．     

三维海陆风的数值模拟

本文利用地形坐标,建立了一个模拟用的三维海陆风模式,来模拟城市、斜坡和海岸形状等对海陆风的影响。结果表明,海陆风主要受海陆温差影响,海岸线附近的坡地和城市的存在,对海风发展有利。     

厦门城市防震减灾工作刍议

本文对1995年1月17日日本阪神大地震的惨重教训进行粗浅分析。针对厦门市城市建设规划及环境地质的实际情况,作者从城市防震减灾体系、抗震设防、老城区改造以及强化地震科普宣传教育等方面,提出了厦门市开展城市减灾工作的建议。     

云南省地震保险研究的优势与不足

地震保险是实现社会互助、减轻国家经济负担、提高抗震救灾能力的有效途径。在国家地震局和中国人民保险总公司的支持下，云南省地震局与云南省保险公司合作，于１９９０年率先开展了地震保险领域的课题研究，现已取得一定的成果。本文就云南省开展该项研究的优势、研究成果和不足等作了介绍。     

Flood disasters and social resilience during the decline of the Qing Dynasty: Case studies of 1823 and 1849

Based on historical records and crop harvest scores extracted from historical documents, this study reconstructed the spatial–temporal distribution and severities of floods in the Yangtze-Huai River valley (YHRV) in 1823 and 1849. We also summarized the effects of the floods on society and identified government measures taken to cope with the floods in the context of the economic recession in the period of 1801–1850. The 1823 flood, which was caused by the heavy precipitation of the Meiyu period and typhoons, severely affected areas in the lower reaches of the Yangtze River. Meanwhile, the 1849 flood, triggered by long-term, high-intensity Meiyu precipitation in the middle and lower reaches of the Yangtze River, mainly affected areas along the Yangtze River. The 1849 disaster was more serious than the one in 1823. In the lower reaches of the Yangtze River, the 1849 flood caused the worst agricultural failure of the period 1730–1852. To deal with the disasters, the Qing government took relief measures, such as exempting taxes in the affected areas, distributing grain stored in warehouses, and transferring grain to severely afflicted areas. These relief measures were supplemented by auxiliary measures, such as exempting commodity taxes on grain shipped to disaster areas and punishing officials who failed to provide adequate disaster relief. The flood disasters disrupted the water system of the Grand Canal and forced the Qing government to transport Cao rice by sea beginning in 1826. This laid the groundwork for the rise of coastal shipping in modern China. With the economic recession of the 19th century, Chinese society was not as resilient to floods as it was in the 18th century. Compared to droughts, floods are more difficult to deal with and pose greater threats to infrastructure and normal life and work in the cities.     

A Climatology Model for Forecasting Typhoon Rainfall in Taiwan

The continuous torrential rain associated with a typhoon often caused flood, landslide or debris flow, leading to serious damages to Taiwan. Thus, a usable scheme to forecast rainfall amount during a typhoon period is highly desired. An analysis using hourly rainfall amounts taken at 371 stations during 1989–2001 showed that the topographical lifting of typhoon circulation played an important role in producing heavier rainfall. A climatology model for typhoon rainfall, which considered the topographical lifting and the variations of rain rate with radius was then developed. The model could provide hourly rainfall at any station or any river basin for a given typhoon center. The cumulative rainfall along the forecasted typhoon track was also available. The results showed that the R² value between the model estimated and the observed cumulative rainfall during the typhoon period for the Dan-Shui (DSH) and Kao-Ping (KPS) River Basins reached 0.70 and 0.81, respectively. The R² values decreased slightly to 0.69 and 0.73 if individual stations were considered. However, the values decreased significantly to 0.40 and 0.51 for 3-hourly rainfalls, indicating the strong influence of the transient features in producing the heavier rainfall. In addition, the climatology model can only provide the average conditions. The characteristics in individual typhoons should be considered when applying the model in real-time operation. For example, the model could give reasonable cumulative rainfall amount at DSH before Nakri (2002) made landfall on Taiwan, but overestimated the rainfall after Nakri made landfall and weakened with significant reduction in convection.