浅析地图集的发展与趋势

梳理了地图集的发展历史,总结了地图集的发展规律,并给出了地图集的发展趋势。     

东南沿海地震区地震活动特性与未来趋势分析

根据地震资料，对东南沿海地震区地震活动特下及未来趋势进行了初步分析与研究，结果表明：（１）从地震活动轮回分析，东南沿海地震区从１９５９年开始的第五个轮回中的地震活动时段，估计将延续到２０３１年前后结束，而后转入本轮回的平静时段；（２）２０００年以前，研究区有可能发生１次Ｍｓ≥６．０地震，到２００５到则最多发生２次；（３）东南沿海地震区下一次发生Ｍｓ≥６．０地震的地区可能在河源－邵武地震带上，尤其可     

山西临汾中心地震台地倾斜震前异常变化特征

从原始记录和分量图两方面对山西临汾中心地震台1991年以来的倾斜资料进行了分析，研究了临汾中心地震台地倾斜与省内及周边地区发生的中强地震的关系。结果表明，对1996年至2002年内发生的几次中强地震，临汾中心地震台地倾斜资料都有较好的异常反映。     

本世纪全球增暖的显著性分析

用Ｊｏｎｅｓ、Ｗａｌａｃｅ等人全球年平均气温距平和全球陆地和海洋月平均气温距平格点资料,通过相关和趋势分析及Ｍａｎｎ－Ｋｅｎｄａｌ趋势检验（以下简称ＭＫＴ检验）发现：本世纪全球绝大部分地区增暖是显著的,而热带、副热带海洋,尤其是印度洋近百年来增暖最稳定．北大西洋近几十年来的显著降温导致了西半球３０°Ｎ以北大部分地区增暖趋势明显下降．与之相反,东半球欧亚大陆近几十年来冬季的强烈增温使地球增暖趋势大大增高,以致形成了东亚大陆和北大西洋－北美大陆东部地区在近５０年来变温反相的不均衡格局     

甘肃省地质灾害变化趋势分析

依全省地质灾害现状及发展变化规律,用时间序列预测法对“九五”期间地质灾害趋势进行了预测,并在此基础上提出了防灾对策,为生态环境、经济、社会效益的协调发展和国土整治、国民经济持续、永续、综合发展提供决策依据。     

Spatial and temporal pattern of precipitation and drought in Gansu Province, Northwest China

Drought is one of the most harmful natural hazards in Gansu Province in Northwest China. The changes of precipitation affect the severity of drought. In order to recognize the trend of precipitation and understand the effect of rainfall change on water resources management and drought severity, Mann–Kendall test was used. Standardized Precipitation Index (SPI) was calculated to reconstruct the drought at different time scales and analyze the frequency of drought occurrence in the recent 50 years. The results show that the SPI is applicable in Gansu Province. The number of severe droughts differs among regions: it is more obvious as a 3-month drought in the Yellow River Basin and the Yangtze River Basin than in the Inland River Basin, and other droughts at 6-, 9-, and 12-month time scales have the same effect in the three regions. Mann–Kendall test results show that there is an upward trend in the summer periods and a downward trend in the autumn-winter-spring intervals ranging from 10.5 mm/10 years to −37.4 mm/10 years, which affect the local water resources management, droughts mitigation, and agriculture decision making. This situation poses challenges for future study.     

利用水位资料反演华北地区构造应力场变化

本文选取华北地区观测条件较好的63口水位观测井资料, 运用小波分析法去除各井水位资料中的短期高频信息, 提取出能反映水位多年动态变化的趋势信息, 并利用各井水位趋势变化数据反演出华北地区多年构造应力场变化图像, 结合其它水文资料, 探讨了华北地区近年来的构造应力场变化特征。     

Trend analysis of nutrient loadings in a large prairie catchment

Nutrient loadings in many river catchments continue to increase due to rapid expansion of agriculture, urban and industrial development, and population growth. Nutrient enrichment of water bodies has intensified eutrophication which degrades water quality and ecosystem health. In this study, we carried out a trend analysis of total phosphorus and total nitrogen loads in the South Saskatchewan River (SSR) catchment using a novel approach to analyse nutrient time series. Seasonal analysis of trends at each of the water quality stations was performed to determine the relationships between annual flow regimes and nutrient loads in the catchment, in particular, the influence of the high spring runoff on nutrient export. Decadal analysis was also performed to determine the long-term relationships of nutrients with anthropogenic changes in the catchment. Although it was found that seasonal and historical variability of nutrient load trends is mainly determined by streamflow regime changes, there is evidence that increases in nitrogen concentration can also be attributed to anthropogenic changes.     

Spatial Variation of Sea Level Trend Along the Bangladesh Coast

The Bangladesh coast is threatened by rising sea level due to various factors. The results based on the analysis of past 22 years of tidal data of the Bangladesh coast reveal that the annual mean tidal level in the eastern Bangladesh coast is rising at an alarmingly high rate of 7.8 mm/year, which is almost twice the observed rate in the western region. This type of sea level trend seems to be the result of changing local conditions like increased precipitation and land subsidence during the recent decades. It seems that the higher rate of land subsidence in the eastern Bangladesh coast is the main causative factor for the steeper sea level trends there. The differential sea level trends show that the subsidence component in the sea level rise may be as high as 4 mm/year in the eastern Bangladesh coast. However, this needs to be verified with actual geological observations.