宝鸡市地质灾害特征及形成主要因素分析

介绍了宝鸡市地质灾害的类型、规模及特征,并着重分析了宝鸡市地质灾害形成的主要因素。认为虽然造成区内地质灾害发生的因素甚多,但近年来大多与人为因素诱发有关。因此,在国土开发和国民经济建设中,应重视对地质环境的保护,避免因人类不适宜的活动而诱发地质灾害。     

石渠地震震害损失的评估及其背景条件

石渠5.1级地震的Ⅶ度(弱)区达160km~2,Ⅵ度区达2470km~2,震害损失值达4300余万元,在对其产生的背景条件和具体原因进行总结分析的同时并对存在的问题作了讨论。     

模糊识别的隶属原则及其应用

由于模糊识别之最大隶属原则,在实际应用中存在着某种上程度上的不足。本文提出了加势隶属原则、积势隶属原则及加权加势隶属原则、加权积势隶属原则。以此可综合考虑各种变量因素,并在最大限度上综合利用各种变量因素间的信息,以达到模糊识别的最佳效应。     

Rupture segmentation and assessment of probabilities of seismic potential on the Xiaojiang fault zone

Spatial distribution of sources of strong and large earthquakes on the Xiaojiang fault zone in eastern Yunnan is studied according to historical earthquake data. 7 segments of relatively independent sources or basic units of rupture along the fault zone have been identified preliminarily. On every segment, time intervals between main historical earthquakes are generally characterized by “time-predictable” recurrence behavior with indetermination. A statistic model for the time intervals between earthquakes of the fault zone has been preliminarily established. And a mathematical method has been introduced into this paper to reckon average recurrence interval between earthquakes under the condition of having known the size of the last event at a specific segment. Based on these, ranges of the average recurrence intervals given confidence have been estimated for events of various sizes on the fault zone. Further, the author puts forward a real-time probabilistic model that is suitable to analyze seismic potential for individual segments along a fault zone on which earthquake recurrence intervals have been characterized by quasi-time-predictable behavior, and applies this model to calculate conditional probabilities and probability gains of earthquake recurring on the individual segments of the Xiaojiang fault zone during the period from 1991 to 2005. As a consequence, it has shown that two parts of this fault zone, from south of Dongchuan to Songming and from Chengjiang to Huaning, have relatively high likelihoods for strong or large earthquake recurring in the future. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 322–330, 1993.     

重力资料的三维密度反演

分别论述了在空间域与频率域中由重力资料反演三维密度分布的理论及其实现的方法,并提出了一种简便、实用的频率域三维密度反演算法。     

2011年日本MW9.0地震对沂沭断裂带及其两侧地区地壳运动的同震影响研究

2011年日本M_W9.0地震（简称日本地震）后沂沭断裂带及其两侧地区地震活动显著增强,研究日本地震对该地区地壳运动及地震潜势的影响十分必要.为此,本文通过112个连续GPS观测站获取了研究区高空间分辨率的日本地震同震形变场并得到如下认识：（1）8个定点地球物理观测的同震响应验证了本文同震形变场的可靠性;日本地震的东向拉张使研究区整体上处于张性同震应变状态,但存在局部挤压区域,其中莱州湾至海州湾的挤压条带穿过沂沭断裂带并对断裂带南北两段产生了不同的同震作用,对南段具有拉张作用,对北段产生挤压作用;（2）同震形变场在鲁东隆起和鲁西断块产生了显著的剪应变,地震b值显示上述区域的构造应力在日本地震后增强,因此同震形变场可能改变了这些区域的应力特征;（3）地震矩张量叠加分析显示,同震形变场短期内对鲁西断块、鲁东隆起区和沂沭断裂带南段累积了地震矩,可能有助于上述区域在日本地震以后的地震活动增强;日本地震对沂沭断裂带北段的地震矩具有释放作用,或许是该区域地震活动减弱的原因.     

中国东南陆缘大地水准面的确定

利用我国东南地区１１８２２个重力数据、３０″×３０″数值地形模型和ＷＤＭ９４重力位模型,以Ｓｔｏｋｅｓ理论为基础,采用低通滤波方法处理远区影响,计算了中国东南陆缘２．５′×２．５′格网重力大地水准面,其结果与福建、山东的ＧＰＳ水准相比较,精度分别为±０．１２４ｍ和±０．０６２ｍ。     

用NCEP／NCAR再分析辐射资料估算月平均地表反照率

本文利用１９７９年￣１９９５年１７年平均的ＮＣＥＰ／ＮＣＡＲ（Ｎａｔｉｏｎａｌ Ｃｅｎｔｅｒ ｆｏｒ Ｅｎｖｉｒｏｎｍｅｎ－ｔａｌ Ｐｒｅｄｉｃｔｉｏｎ／Ｎａｔｉｏｎａｌ Ｃｅｎｔｅｒ ｆｏｒ Ａｔｍｏｓｐｈｅｒｉｃ Ｒｅｓｅａｒｃｈ,美国国家环境预报中心／美国国家大气研究中心）再分析辐射资料估算了全球月平均地表反照率．从所得结果的时空分布来看,用ＮＣＥＰ／ＮＣＡＲ辐射资料得到的全球地表反照率基本     

Detecting patterns of climate change in long-term forecasts of marine environmental parameters

ABSTRACT

Forecasting environmental parameters in the distant future requires complex modelling and large computational resources. Due to the sensitivity and complexity of forecast models, long-term parameter forecasts (e.g. up to 2100) are uncommon and only produced by a few organisations, in heterogeneous formats and based on different assumptions of greenhouse gases emissions. However, data mining techniques can be used to coerce the data to a uniform time and spatial representation, which facilitates their use in many applications. In this paper, streams of big data coming from AquaMaps and NASA collections of 126 long-term forecasts of nine types of environmental parameters are processed through a cloud computing platform in order to (i) standardise and harmonise the data representations, (ii) produce intermediate scenarios and new informative parameters, and (iii) align all sets on a common time and spatial resolution. Time series cross-correlation applied to these aligned datasets reveals patterns of climate change and similarities between parameter trends in 10 marine areas. Our results highlight that (i) the Mediterranean Sea may have a standalone ‘response’ to climate change with respect to other areas, (ii) the Poles are most representative of global forecasted change, and (iii) the trends are generally alarming for most oceans.     

热带气旋生成指数对印度洋热带气旋频数变化的适用性研究

本文利用ERA5 1979-2019年逐月大气再分析资料计算南北印度洋热带气旋生成指数，并和IBTrACS观测数据进行比较，探讨用热带气旋生成指数研究南北印度洋热带气旋变化特征的适用性.研究发现热带气旋生成指数能较好地刻画南北印度洋热带气旋的空间分布特征、北印度洋热带气旋个数月变化的双峰结构，以及南印度洋比北印度洋热带气旋发生概率高等特征.最新的IBTrACS v4.0观测资料显示，40年来北印度洋热带气旋每年总生成个数平均每10年增加1.3个，频数的增加主要来源于热带低压和热带风暴，而南印度洋热带气旋每年总生成个数每10年减少2.8个.热带气旋生成指数能很好地描述北印度洋热带气旋生成个数的上升趋势，但对南印度洋热带气旋生成个数趋势的刻画与观测不一致，可能原因需要进一步深入研究.