Water Security-based Hydrological Regime Assessment Method for Lakes with Extreme Seasonal Water Level Fluctuations: A Case Study of Poyang Lake,China

Extreme seasonal water level fluctuations characterize natural floodplain lakes in monsoon regions, which are crucial for ensuring lake water security, including flood prevention water supply and health of aquatic ecosystem. In order to achieve this goal, we established a hydrological regime assessment method based on a set of hydrological indicators for lakes with heavy seasonal water level fluctuations. The results suggest that time-sensitive hydrological indicators and specific time scales for various water security aspects must be considered. We discovered that it is more practical and meaningful to combine the water level classification derived from statistical analyses with characteristic hydrological values linked to water security. The case study of Poyang Lake results show that there are no discernable trends of Poyang Lake water regime status over the last 35 years, and the two periods of poor status are in accordance with climate variation in the lake basin area. Scholars and policy makers should focus on both floods and droughts, which are the main water security problems for Poyang Lake. It is hoped that this multi-scale and multi-element hydrological regime assessment method will provide new guidelines and methods for other international scholars of river and lake water assessment.     

Postcrystallization thermal evolution history of Gangdese batholithic zone and its tectonic implication

Using cooling curves of K-feldspars obtained by using specific⁴⁰Ar/³⁹Ar stepe heating procedure and multiple diffusion domain modeling (MDD model), together with results of dating hornblends, biotite, and apatite, further work has been done to examine the characteristics of the postcrystallization thermal evolution history of Gangdese batholithic zone, to compare the starting times of rapid cooling events with the variation regularities of apatite fission track (FT) ages in the eastern and western parts of Gangdese batholithic zone, and to provide the evidence for mass transport and energy transfers in the lithosphere after the collision between Indian and Eurasian plates. Project supported by the National Natural Science Foundation of China (Grant No. 49473171).     

Determination of the absolute32S/34S ratio of IAEA-S-1 reference material and V-CDT sulfur isotope standard

The absolute³²S/³⁴S ratios of IAEA-S-1 reference material and V-CDT standard are determined. For cross-checking, two sets of synthetic isotope mixtures are prepared from high purity³²S and³⁴S-enriched materials in different forms: the first set is prepared from BaSO₄ whereas the second is prepared from Ag₂S. The sulfur isotope analyses are done by using SF₆ method with a MAT-251 EM mass spectrometer. The resulting³²S/³⁴S ratio of IAEAS-1 reference material is 22. 656 4 ±0.006 0, and that of V-CDT is 22.649 6 ± 0.006 0. Project supported by the National Natural Science Foundation of China (Grant No. 86020341).     

长输埋地管道振动台试验传感器布置方案研究

在进行长输埋地管道振动台试验的过程中,针对数据信息的采集量测以及传感器的布置位置进行了研究。采用三维数值模拟的方法对管-土相互作用体系进行了地震反应分析,内容包括埋地管道结构纵、横向在非一致地震动作用下的地震响应及受力变形特征。根据计算结果确定了主观测断面及辅助观测断面的位置及观测断面上传感器布置的位置,在满足基本信息采集要求的前提下,对可供采用的信息采集通道进行了优化分配,由此确定本次试验的观测断面以及传感器的具体测量部位与数目。成果对试验获得成功起到了保障作用,可为同类试验提供参考。     

地基GNSS遥感探测气象应用

全球导航卫星系统（GNSS）给定位、导航和授时服务带来了革命性变化,同时其L波段（1160～1610MHz）微波信号可用于全球覆盖、高时间分辨率的大气、海洋和陆表参数遥感探测。基于信号类型,GNSS遥感可分为折射信号遥感和反射信号遥感两大类;基于探测平台,GNSS遥感可分为地基GNSS遥感、空基GNSS遥感和天基GNSS遥感三大类。随着我国自主建设的北斗卫星导航系统全面建成,GNSS遥感将迎来新的发展机遇和挑战。本文回顾近20年地基GNSS遥感探测在气象领域的应用进展,展望其在气象领域下一步可能的应用。     

基于Matlab GUI的全球重力固体潮可视化实现

阐明重力固体潮理论值计算原理,利用改进的计算新方法编写Matlab计算程序,采用Matlab中的GUI平台,对全球重力固体潮进行可视化实现,直观观察固体潮在地面的时空变化规律。通过输入时间和经纬度,确定采样间隔(秒采样、分钟采样、时采样),实现以下功能:(1)以图像和Excel形式,输出某一地区的重力固体潮理论值;(2)仿真未来24小时全球重力固体潮。     

钟祥马岭井水温观测数据"V"型异常分析

以钟祥马岭井历年水温观测资料为研究对象,发现2套SZW-1A型数字水温仪记录的数据曲线自2016年7月以来均具有“V”型异常特征,从观测系统、地震、降雨等因素进行分析,排查干扰因素,并分析水温变化的可能机理,认为现该异常应为降雨干扰所致。干扰机理如下：降雨量累积值达40 mm以上,降雨迅速补充地下水,浅层冷水经井段223—246 m处存在的岩石裂隙、断层、溶洞等渗入井孔,造成静水位迅速上升,井水温度随之下降,上下层冷—热水之间的热传导使得位于井孔深部的水温下降;降雨结束,地表水渗入量减少,水温逐渐恢复正常。     

百度地图位置解析技术在地震应急基础数据库的应用

分析百度地图位置解析技术功能及特点,提出使用地址解析及坐标转换功能,对地震应急基础属性数据进行解析,实现基础属性数据空间化,设计地理坐标纠偏算法,提高地震应急基础数据的可用性,为地震应急工作提供数据保障。该算法操作简单,运行快捷,解决了地震应急基础数据库中属性数据及时更新的关键技术问题。     

Observational and model studies of synoptic current fluctuations in the Bohai Strait on the Chinese continental shelf

Ocean Dynamics - Three winter storms struck the Bohai and Yellow seas in succession during February 16–25, 2017. Periodic fluctuations of sea level, currents, temperature, and salinity were...     

2019年6月17日四川长宁6.0级地震中心震源机制解及震源区构造应力场研究

不同资料和方法给出的2019年6月17日四川长宁6.0级地震震源机制解存在较大差异,为了找到1个合适的震源机制解来研究此次地震的发震方式,通过数学方法得到了与现有震源机制解差别最小的中心震源机制解,节面I的走向、倾角、滑动角分别为194.78°、52.68°和139.16°,节面Ⅱ的走向、倾角、滑动角分别为312.44°、58.67°和45.22°,根据本次地震余震分布拟合得到的断层面的走向为312.17°,与中心震源机制的节面Ⅱ走向一致,因而推断节面Ⅱ为本次地震的发震断层面。之后,利用此次地震之前震源区地震的震源机制解,反演了震源区的震前构造应力场。结果表明,长宁6.0级地震的中心震源机制解和震源区震前应力场均为逆冲型为主兼走滑分量的类型,震前应力场压轴为NWW—SEE向,中间轴为NNE—SSW向,两轴倾角接近水平,而张轴较陡,表现为逆冲型的应力场。将反演得到的应力场投影到中心震源机制解给出的与余震分布一致的节面上,发现中心震源机制解的滑动角和应力场预测的滑动角差别仅为13.45°,表明此次地震受背景应力场控制而发生在先存的薄弱面上。