宿迁地震台地震监测能力分析

根据宿迁地震台地震计和数采参数、台站背景噪声等数据,结合历史地震观测数据,运用统计学计算方法,计算宿迁地震台地震监测能力。结果认为:宿迁地震台短周期台基背景噪声较大,微小地震监测能力较弱,但基本可以监测到M_L 2.0地方震,也可监测到150 km范围内周边城市M_L 2.5地震。     

库尔勒地震台地震监测能力初探

主要选用库尔勒地震台测点单台地震目录,运用单台小震优势分布法、logN-M法和b值计算法然后采用M-△法对结果进行验证。对库尔勒台监测点300km范围内的地震监测能力进行了初步分析和讨论,确定库尔勒台监测点300km以内的控震能力;再依此方法确定了库尔勒附近的库米什台300km以内的地震监测能力。     

嘉峪关地震台地震定位方位偏差研究

对嘉峪关地震台记录的500个地震逐一分析定位,将本台和中国地震台网中心的定位结果对比,统计平均偏差率。详细计算本台及3个子台的四象限定位结果偏差率,对发生方位偏差的震中位置进行归类研究,寻找规律。研究发现,远震定位结果受台基噪声影响大,近震定位结果受地质构造中断层影响大。应用方位角法定位地震可以最大限度地增加定位准确度,近地震速报时注意肃南区域方位异常的偏差角度,可提供较为准确的地震参数。     

嘉峪关地震台地震定位方位偏差研究

对嘉峪关地震台记录的500个地震逐一分析定位,将本台和中国地震台网中心的定位结果对比,统计平均偏差率。详细计算本台及3个子台的四象限定位结果偏差率,对发生方位偏差的震中位置进行归类研究,寻找规律。研究发现,远震定位结果受台基噪声影响大,近震定位结果受地质构造中断层影响大。应用方位角法定位地震可以最大限度地增加定位准确度,近地震速报时注意肃南区域方位异常的偏差角度,可提供较为准确的地震参数。     

鹤岗地震台阵地震波形特征分析

为了提高我国微小地震监测能力,"一带一路"项目拟在黑龙江鹤岗地区建设地震台阵。在2019年8月4日至9月4日,鹤岗地震台阵监测到部分近震及远震,与黑龙江省鹤岗地震台观测数据进行对比分析,得到以下结果：与鹤岗地震台相比,鹤岗地震台阵对近震及区域性地震的监测能力较高,对远震和极远震的监测范围较大,记录完整的地震个数更多,整体背景噪声更小,地震波形质量更高,定位更精确,提高了区域地震监测能力。     

攀枝花地震台数字地震分析探讨

结合地震波记录原理,分析并讨论攀枝花台数字仪震相的一些物理特征,并使用MATLAB对攀枝花、长春台的地震资料做简单滤波分析,便于真实地反映地震波震相。参考川滇交界地区地质构造,总结出攀枝花台对多次地震记录震相分析的经验规律,为地震速报快速识别震相提供实用参考。     

嘉山地震台模拟和数字记录地震对比分析及台基评价

通过对嘉山地震台测震模拟与数字观测系统并行运行观测资料的对比分析,阐述了测震台宽频带数字地震观测系统,在区域地震台网速报和观测资料应用研究方面的作用和价值.同时,也对嘉山地震台的台基地动噪声水平进行了基本评估,提出了改善嘉山地震台地震检测能力应采取的措施.     

牡丹江地震台与密山地震台供电系统故障分析

黑龙江省“十五”数字地震观测网络项目自2007年完成建设并开始运行,其中牡丹江地震台新增形变、火山测震台网等观测项目,密山台新增测震,大地电场等观测项目。台站运行期间,地震专业仪器设备出现设备故障及损坏情况,经过对台站技术系统的分析,判断牡丹江地震台和密山地震台由农电局供电的交流供电系统存在问题,本文分析了故障产生的原...     

山西地震台网地震预警时间及盲区半径分析

影响地震预警能力的关键技术指标是预警时间及预警盲区。通过分析山西地震台网勘选完成的1 101个预警台站布局,计算地震台站平均台间距,根据预警盲区半径与台间距关系式得出盲区半径。根据计算结果及相关分布图,分析认为,在预警区内,平均台间距及盲区半径分布与地震活动的相关性较高,勘选完成的地震预警台站布局比较合理。     

地震流动台的建立和维护

破坏性地震发生时,地震部门往往需派出人员到地震现场评估地震灾害和建立地震观测台站（流动台）,监测地震活动情况。１建立流动台时的准备工作在确定地震流动台的建台人员和守台人员后,还须将流动台的仪器设备和建台物资准备好。地震记录仪、拾震器和通讯设备（电台）...     

滇西怒江断裂带新构造特征

怒江断裂带从走向上可以分为南北走向段和北东走向段,其喜马拉雅期的构造变形以右行剪切为主导。右行剪切的变形历史可以分为早期压剪变形和晚期张剪变形两个大的阶段。这两期变形各自在南北走向段和北东走向段表现出不同的特点。总之,怒江断裂带喜马拉雅期构造变形具有时空不均一性的特点     

Recent trends of extreme precipitation indices in the Iberian Peninsula using observations and WRF model results

Spatial and temporal distributions of the trends of extreme precipitation indices were analysed between 1986 and 2005, over the Iberian Peninsula (IP). The knowledge of the patterns of extreme precipitation is important for impacts assessment, development of adaptation and mitigation strategies. As such, there is a growing need for a more detailed knowledge of precipitation climate change.This analysis was performed for Portuguese and Spanish observational datasets and results performed by the Weather Research and Forecast (WRF) model forced by the ERA-Interim reanalysis. Extreme precipitation indices recommended by the Expert Team for Climate Change Detection Monitoring and Indices were computed, by year and season. Then, annual and seasonal trends of the indices were estimated by Theil-Sen method and their significance was tested by the Mann-Kendal test. Additionally, a second simulation forced by the Max Planck Institute Earth System Model (MPI-ESM), was considered. This second modelling configuration was created in order to assess its performance when simulating extremes of precipitation.The annual trends estimated for the 1986–2005, from the observational datasets and from the ERA-driven simulation reveal: 1) negative statistically significant trends of the CWD index in the Galicia and in the centre of the IP; 2) positive statistically significant trends of the CDD index over the south of the IP and negative statistically significant trends in Galicia, north and centre of Portugal; 3) positive statistically significant trends of the R75p index in some regions of the north of the IP; 4) positive statistically significant trends in the R95pTOT index in the Central Mountains Chain, Leon Mountains and in the north of Portugal.Seasonally, negative statistically significant trends of the CWD index were found in Galicia, in winter and in the south of the IP, in summer. Positive statistically significant trends of the CWD index were identified in the Leon Mountains, in spring, and in Galicia, in autumn. For the CDD index, negative statistically significant trends were seen in Valencia, in the spring, and, in Galicia and Portugal (north and centre), in summer. Positive statistically significant trends of the CDD index were found: in the east of the IP, in the winter; in the Cantabrian Mountain, in the spring; and, in the south of the IP, in summer. Regarding to the R75p index, negative statistically significant trends were found in Galicia, in winter and positive statistically significant trends in the north of Portugal, in spring and in the Central Mountains Chain and north of Portugal, in autumn. For the R95pTOT index, negative statistically significant trends were found over the Sierra Cuenca and Sierra Cazorla, in winter and positive statistically significant trends were found over the Sierra Cebollera, in winter and in Castile-la Mancha region, in spring.The results of the annual and seasonal trends of the extreme precipitation indices performed for observational datasets and the simulation forced by ERA-Interim, are similar. The results obtained for the simulation forced by MPI-ESM are not satisfactory, and can be a source of criticism for the use of simulation forced by MPI-ESM in this type of climate change studies. Even for the relatively short period used, the WRF model, when properly forced is a useful tool due to the similar results of Portuguese and Spanish observational datasets and the simulation forced by ERA-Interim.     

Spatial and seasonal patterns of flood change across Brazil

Brazil has some of the largest rivers in the world and has the second greatest flood loss potential among the emergent countries. Despite that, flood studies in this area are still scarce. In this paper, we used flood seasonality and trend analysis at the annual and seasonal scales in order to describe flood regimes and changes across the whole of Brazil in the period 1976–2015. We identified a strong seasonality of floods and a well-defined spatio-temporal pattern for flood occurrence. There are positive trends in the frequency and magnitude of floods in the North, South and parts of Southeast Brazil; and negative trends in the North-east and the remainder of Southeast Brazil. Trends in the magnitude (frequency) were predominant in the winter (summer). Overall, floods are becoming more frequent and intense in Brazilian regions characterized by wet conditions, and less frequent and intense in drier regions.     

中国特有种大型桡足类舌状叶镖水蚤(Phyllodiaptomus tunguidus)在广东水库中的分布特征

舌状叶镖水蚤(Phyllodiaptomus tunguidus)是我国特有的大型哲水蚤,主要分布在我国华南地区.根据2000年对广东省19座典型大中型水库的2次采样和2002年对流溪河水库和新丰江水库的5次采样,重点测定了流溪河水库、新丰江水库和鹤地水库等3座大型水库中舌状叶镖水蚤个体体长及形态参数,分析了广东省大中型水库中舌状叶镖水蚤的种群与个体大小的分布特征.在对19座水库的2次采样中,11座水库发现该种成体,其中5座水库在丰水期没有出现该种的成体,6座水库在丰水期和枯水期都有该种类成体的出现.丰水期与枯水期舌状叶镖水蚤的平均丰度分别为0.465ind./L和0.996ind./L.舌状叶镖水蚤主要出现在大型水库中,特别是贫营养的大型水库,其丰度主要由食物数量、质量与捕食压力所决定.2002年,流溪河水库丰度和新丰江水库舌状叶镖水蚤全年的平均值为1.308ind./L和0.294ind./L,丰水期高于枯水期.在个体大小和形态特征上,2座贫营养水体——流溪河水库、新丰江水库的舌状叶镖水蚤的体长与第一触角长度均大于中营养水体——鹤地水库,这种形态上的差异是由鱼类捕食方式(滤食或选择性捕食)所决定.     

淮河流域焦岗湖水质参数时空变化及影响因素

焦岗湖是淮河左岸一个天然湖泊,集防洪、灌溉、养殖、旅游等多种功能于一体.利用焦岗湖4个季节水质监测数据,运用Kriging方法,分析焦岗湖水质参数的时空变化及影响因素.结果表明:由于受水文季节变化过程及人类活动等综合影响,焦岗湖水质参数在时间及空间上均存在一定差异.从时间变化来看,夏季透明度较低、秋季较高;溶解氧浓度在春、冬季显著高于夏、秋季;总氮、总磷浓度与高锰酸盐指数均表现为夏季最高、秋季最低.从空间变化来看,4个季节的透明度空间差异较为显著;溶解氧浓度在春、冬季空间分布较为均匀,夏季呈现中心高周围低的变化趋势,秋季则表现为西高东低;总磷浓度春季分布较为均匀,夏、秋及冬季则呈西高东低之势;高锰酸盐指数在春、秋季节呈现东高西低之势,夏季高浓度主要集中在湖区北部,冬季浓度变化不大.     

大通湖及东洞庭湖区生物体重金属的水平及其生态评价

于2005年11月采集了大通湖及东洞庭湖区湖水和水生生物样品,并测定了水和水生生物样品中重金属(Cd、Pb、Hg、As)的含量,并对湖区生物体重金属进行了污染评价.研究结果表明,大通湖及东洞庭湖区湖水中重金属含量较小,绝大部分采样点水质都属于国家Ⅰ类水标准;水生生物体内CD、Pb含量为虾＞螺＞鱼,Hg的含量为鱼＞螺＞虾,As的含量为螺＞虾＞鱼;而鱼类重金属含量则为底栖鱼类＞中上层鱼类,肉食性鱼类＞植食性鱼类.大通湖及东洞庭湖区生物体中CD、Pb的污染指数为虾＞螺＞鱼,Hg的污染指数则为鱼＞螺＞虾,As的污染指数则为螺＞虾＞鱼.     

Bioassessment Techniques for Monitoring of Eutrophication and Nutrient Limitation in Coastal Ecosystems

Bioassesment by the use of the macroalga, Ulva lactuca L., was carried out in the Limfjord, Denmark, to assess the significance of nitrogen and phosphorus as limiting factors for primary production during 1985, 1993, 1994 and 1995 and for the detection of changes in eutrophication levels.

Minimum and critical tissue concentrations for nitrogen and phosphorus in macroalgae were identified. The concentrations of nitrogen were generally below the critical concentration level in June–October in 1985, 1993, and 1995 but in 1994 nitrogen was only limiting for primary production in short periods. Only in early spring in 1985 and 1993 were the tissue concentrations of phosphorus below the critical concentration level, whereas in 1994 up to 3–4 months showed phosphorus limited growth, indicating that significant changes in limitation patterns can occur between different years.

It was concluded that the use of biomonitoring techniques is well suited as a bioassessment method for direct detection and for providing a time-integrated measure of nutrient availability in coastal waters, and thus for assessing ecosystem health with regard to eutrophication. It is recommended that biomonitors and the concept of critical tissue concentrations should be used in environmental management and incorporated in future monitoring programmes.     

渤海及周围地区断裂构造与强震活动研究

分析研究了渤海及周围地区断裂构造和强震活动特征,初步探讨了海及周围地区的地球动力学问题。结果表明,渤海及周围地区断裂和地震活动存在着内在的成生联系,其突出特征是时空上的非均匀性。断虺用地震活动在空间上具有成带、分段、分区和衰减特征。是间上,晚更新世界期（２～３方ａ）是断裂整体活动时间,全新世断虺工减弱,范围缩小,粘骨破裂具有上千年的周围,１５００年以来地震活动呈活跃与平静的交替。板块运动产生的区域     

Changes in an urban water resource,an example from Sydney,Australia

This paper examines present and future resource utilization in the tidal section of the Georges River in the southern part of Sydney. Over the last 30 years, the physical characteristics of the river have changed as a result of urbanization, changed hydrologic regime and sand dredging. Urbanization has resulted in an increase in population from 190,000 in 1947 to 550,000. This has resulted in an increase in runoff, sediment input to the river and waste disposal. The change in hydrologic regime has resulted in a substantial increase in the magnitude and frequency of flooding which has increased erosion. Sand dredging has increased the channel capacity, enlarged the tidal prism and increased water turbidity. It has also resulted in extensive bank erosion in the upper part of the river and extensive deposition lower down as tailings are deposited. Although most of these changes have resulted in the deterioration of environmental quality, use of the river for recreation and as an urban amenity has increased.