共查询到20条相似文献，搜索用时 781 毫秒
1.
1 1999年河北省及京津地区地震活动实况 1.1 据河北省地震台网测定,1999年1月1日至12月31日河北省及京津地区共发生地震677次,ML1.0～1.9级地震445次,ML2.0～2.9级地震197次,ML3.0～3.9级地震31次,ML4.0～4.9级地震4次,ML≥5.0级地震1次,最大地震为1999年3月11日ML5.6级地震,见图1. 相似文献
2.
1 2006年河北省及京津地区地震活动概况 据河北省数字遥测地震台网测定,2006年河北省及京津地区共发生地震847次,ML1.0级以下地震144次,ML1.0～1.9级地震611次,ML2.0～2.9级地震82次,ML3.0～3.9级地震7次,ML4.0～4.9级地震2次,ML5.0以上1次(见图1). 相似文献
3.
１１９９８年河北省及京津地区地震活动实况１．１据河北省地震台网测定,１９９８年１月１日至１２月３１日河北省及京津地区共发生地震１７０８次,ＭＬ＜２．０级地震１１９１次,ＭＬ２．０～２．９级地震３６３次,ＭＬ３．０～３．９级地震１２２次,ＭＬ４．０～４... 相似文献
4.
2004年华北及河北省地震活动概况 总被引：1，自引：0，他引：1
1 2004年河北省及京津地区地震活动概况据河北省数字遥测地震台网测定,2004年河北省及京津地区共发生地震1053次,ML1.0级以下地震153次,ML1.0～1.9级地震752次,ML2.0～2.9级地震131次,ML3.0～3.9级地震13次,ML4.0～4.9级地震3次,没有5级地震(见图1)。最大地震为2004年1月20日河北滦县昌黎交界(39°43!@N118°46!@E)的ML4.7级地震。2004年1月20日发生在河北滦县昌黎交界的ML4.7级地震和2004年3月13日发生在图1 2004年河北省及京津地区地震震中分布图唐山的ML4.1级地震,都是非常显著的地震,2004年河北省及津京地区的地震活动仍然比… 相似文献
5.
1 2 0 0 1年河北省及京津地区地震活动概况据河北省地震台网测定 ,2 0 0 1年 1月 1日至 12月 31日河北省及京津地区共发生地震 6 73次 ,ML2 .0级以下地震 5 0 3次 ,ML2 .0～ 2 .9级地震 146次 ,ML3.0～ 3.9级地震 2 0次 ,ML4.0～ 4.9级地震 4次 ,最大地震为 2 0 0 1年 3月 2日宣化 ML4.4级。见图 1。图 1 2 0 0 1年河北省及京津地区地震活动分布图2 2 0 0 1年河北省及京津地区地震活动特征从河北省及京津地区 1990年以来地震活动统计表 (表 1)可以看出1小震频度低 :从 1990年以来至 2 0 0 1年 12月小震频度达到最低值仅有 6 73次 … 相似文献
6.
2009年华北及河北省地震活动概况 总被引：1，自引：1，他引：0
1 2009年河北省及京津地区地震活动概况
据河北省数字遥测地震台网测定,2009年河北省及京津地区共发生地震1180次,ML1．0级以下地震356次,ML1.0～1．9级地震684次,ML 2．0～2．9级地震131次,ML3．0～3．9级地震9次,没有4级以上地震（图1）。最大地震为2009年11月22日17点09分56．5秒天津宁河（39°07′N 117°13′E）的ML3．7级地震。 相似文献
7.
1 2 0 0 0年河北省及京津地区地震活动实况1 .1 2 0 0 0年河北省及京津地区地震活动特征据河北省地震台网测定 ,2 0 0 0年 1月 1日至 1 2月 31日河北省及京津地区共发生地图 1 2 0 0 0年河北省及京津地区地震活动分布图震 851次 ,ML2 .0级以下地震 62 7次 ,ML2 .0～ 2 .9级地震 1 84次 ,ML3.0～3.9级地震 37次 ,ML4 .0～ 4 .9级地震 3次 ,最大地震为 2 0 0 0年 6月 2 5日唐山 ML4 .4级 (见图 1 )。从河北省及京津地区 1 990年以来地震活动统计表可以看出 :1小震频度底 ;从 1 990年以来至2 0 0 0年 1 2月小震频度达到最低值仅有 85… 相似文献
8.
2005年华北及河北省地震活动概况 总被引：1，自引：0，他引：1
1 2005年河北省及京津地区地震活动概况据河北省数字遥测地震台网测定,2005年河北省及京津地区共发生地震926次,ML1.0级以下地震136次,ML1.0~1.9级地震651次,ML2.0~2.9级地震127次,ML3.0~3.9级地震14次,没有4级地震(见图1)。最大地震为2005年8月31日河北蔚县(40°00′114°49′ 相似文献
9.
1 2010年河北省及京津地区地震活动概况
据河北省数字遥测地震台网测定,2010年河北省及京津地区共发生地震1 610次,ML1.0级以下地震600次．ML1．0～1．9级地震835次,ML2．0～2．9级地震153次．M1,3．0～3．9级地震20次, 相似文献
10.
1 1995年河北省及京津地区地震活动实况1.1 据河北省地震台网测定,1995年1月1日至1995年12月31日河北省及京津地区共发生地震1382次,M_L<2.0级地震1110次,M_L2.0～2.9级地震246次,3.0～3.9级地震25次,M_L≥5.4级地震1次,最大地震为1995年10月6日滦县Ms5.0级地震.1.2 1995年河北省及邻近地区发生了多次小震群活动,特别是1995年7月20日涿鹿震群持续时间长达半年多,呈现了震级大、持续时间长、衰减异常的特点. 相似文献
11.
In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations （CSs）, as well as discharge and sediment transport at 3 Gauging Stations （GSs） are used to assess the features of sediment transport in the Kuye River. The rtmoff modulus （defined as the annual average discharge per unit area, L/（s·km^2）） and the sediment transport modulus （defined as the annual suspended sediment transport per unit area, t/（yr km^2）） are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m^3/s in August with an average monthly sediment concentration of 88.9 kg/m^3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m^3 and occurs in July, which has an average discharge of 42.6 m^3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye River is largest in February and then decreases until June. In July, the average monthly median grain size of suspended load approaches another peak and decreases until September. Then, the median grain size of suspended load starts to increase until February of the following year. However, the average monthly median grain size of suspended load in the Yellow River at Toudaoguai and Longmen GSs is the smallest between early summer and late fall The median grain size in the Yellow River starts to increase in November and approaches the largest size in January. 相似文献
12.
13.
Observations of trace gases (SO2, NH3, NO2 and O3) were made during the period 1981 to 1984 at 6 different locations representative of urban industrial, urban, nonurban, thermal power plant and marine environment. Diurnal variations of the trace gases were studied in an urban environment. Except in the urban industrial environment, the concentration of NH3 was found in the range of background values. Also, the average concentrations of NO2 and O3 at the different environments were in the order of background values. However, the concentrations of SO2 were substantially higher by about 7 times, in urban industrial and thermal power plant environments. The diurnal variations of SO2, NH3 and NO2 showed anitphase relationship with surface temperature at the urban environment station which is relatively free of industrial pollution. Discussion is centred on trace gas variations in different environments in India together with the values reported for various countries in the world. 相似文献
14.
3He/4He ratios up to 3.5 times the ratio of atmospheric He were found in groundwater samples. The3He enrichment can be attributed to radiogenic3He produced by in-situ beta-decay of3H. This shows that tritiogenic3He is accumulating in confined waters. From tritiogenic3He and3H concentrations, ages of groundwaters can be calculated. Detection of tritiogenic3He gives a tool to trace a tritium contamination which occurred in the past and cannot be assessed only by the3H counting method. 相似文献
15.
The aim of this study is to estimate likely changes in flood indices under a future climate and to assess the uncertainty in these estimates for selected catchments in Poland. Precipitation and temperature time series from climate simulations from the EURO-CORDEX initiative for the periods 1971–2000, 2021–2050 and 2071–2100 following the RCP4.5 and RCP8.5 emission scenarios have been used to produce hydrological simulations based on the HBV hydrological model. As the climate model outputs for Poland are highly biased, post processing in the form of bias correction was first performed so that the climate time series could be applied in hydrological simulations at a catchment-scale. The results indicate that bias correction significantly improves flow simulations and estimated flood indices based on comparisons with simulations from observed climate data for the control period. The estimated changes in the mean annual flood and in flood quantiles under a future climate indicate a large spread in the estimates both within and between the catchments. An ANOVA analysis was used to assess the relative contributions of the 2 emission scenarios, the 7 climate models and the 4 bias correction methods to the total spread in the projected changes in extreme river flow indices for each catchment. The analysis indicates that the differences between climate models generally make the largest contribution to the spread in the ensemble of the three factors considered. The results for bias corrected data show small differences between the four bias correction methods considered, and, in contrast with the results for uncorrected simulations, project increases in flood indices for most catchments under a future climate. 相似文献
16.
Changes in thermal extremes of the climate of Poland in 1951–2010 are examined. Warm extremes have become more frequent, while cold extremes have become less frequent. In the warming climate of Poland, the increase in the number of extremely warm days in a year and the decrease in the number of extremely cold days in a year have been observed. Also the increase of the maximum number of consecutive hot days in a year and the decrease of the maximum number of consecutive very cold and extremely cold days in a year have been observed. However, the trends are not of ubiquitous statistic significance, as the natural variability is strong. 相似文献
17.
Cu concentrations in surface (river and lake) and subsurface waters are determined. The geographic pattern of Cu distribution in natural water is identified. This pattern is controlled by the difference between its concentrations in drained rocks and soils and the geochemical redox conditions of its migration. Territories with low, medium, and elevated Cu concentrations in natural waters are identified. The concentrations of Cu in natural waters of the region are found to be generally lower than the Clarke values. 相似文献
18.
M. MONIRUL QADER MIRZA 《水文科学杂志》2013,58(5):613-631
Abstract The basin area of the Ganges River in Bangladesh is extremely dependent on a regular water supply from upstream to meet requirements for agriculture, fisheries, navigation, salinity control, and domestic and industrial sectors. In 1975, India commissioned a barrage on the Ganges River at Farakka to divert a significant portion of the dry season flow in order to make the Calcutta Port navigable. Statistical analyses of discharge and water level data have been carried out to determine if significant changes have occurred in the hydrology of the Ganges system in Bangladesh in the post-Farakka period. Siltation of the Gorai River (an offtake of the Ganges River) has also been examined using the stage-discharge relationship and regression analysis. The analyses show that the diversion has caused considerable hydrological changes in the Ganges system in Bangladesh. The water supply in the dry season has been reduced substantially, while siltation of the Gorai River has increased significantly. 相似文献
19.
20.