Using finite element and Okada models to invert coseismic slip of the 2008 Mw 7.2 Yutian earthquake, China, from InSAR data

We invert InSAR from ascending and descending passes of ENVISAT/ASAR data to estimate the distribution of coseismic slip for the 2008 Mw 7.2 Yutian earthquake by separately using uniform finite element models (FEMs), non-uniform FEMs, and analytical elastic half-space (Okada) models. We use the Steepest Descent method and Laplacian smoothing to regularize and estimate the slip distribution for each of these different models. Fault surface ruptures interpolated from Quickbird optical images constrain the strike of the fault. The uniform FEM and Okada models assume a fault embedded in a homogeneous and elastic finite domain or half-space, respectively, while the non-uniform FEM describes a domain with spatially variable elastic properties according to the geological structure of Tibet plateau and Tarim. We find that the estimated slip distribution of the non-uniform FEM is similar to that of the uniform FEM but has a slightly larger moment (~2 %). However, more noticeable discrepancies occur between the slip distributions of the uniform FEM and Okada model, where the slip pattern estimated with the FEM looks more scattered and locates at a lower depth. We conclude that, for the case of the Yutian earthquake, the improvement brought by simulating the distribution of geologic material properties is insignificant. This suggests that the uniform geologic structure of Okada models may be sufficient for simulating large intra-continental earthquakes.     

青岛市城中村土地征用(收)调查

随着全国大部分地区尤其是东部沿海区域城市化发展进入加速期,城区土地资源紧张问题愈发显现。同时城区内大片旧城区和城中村的改造,影响着城市化能否顺利实施,为了破解这一城市发展难题,青岛市国土部门创新思路,探索实施新的城中村土地征用(收)办法,全方位保障被拆迁群众的利益,推动了城市化的顺利实施,促进了社会的和谐和城市经济健康发展。     

SAR遥感图像在汶川地震灾害识别中的应用

汶川地震发生后,受阴雨天气的影响,光学遥感影像在救灾决策中的作用受到了很大的限制,而SAR图像由于其全天候的特点成为这次抗震救灾前期遥感信息保障十分重要的数据源.采用ENVISAT的ASAR作为数据源,利用多时相的雷达数据的幅度及相位信息对映秀及周边地区做了地震灾害识别,其中利用震前震后的幅度图像做比值变化检测,在映秀镇及紫坪铺水库等山区取得了较好的效果;利用相位信息做干涉处理得到的相干图像,经过失相干分析,发现建筑物的破坏等级与相干系数变化指数的大小高度相关.比较这两种方法,在都江堰等平原地区由于失相干现象不像山区那么严重,并且利用比值处理可以去除部分空间失相干及系统热噪声等带来的干扰因素,可以成为幅度图像的有益补充.结果表明,结合SAR幅度影像和干涉相干影像,可以在地震灾害评估中取得更好效果.随着极化干涉雷达技术的日益成熟,多时相幅度信息、相位信息等多特征SAR影像信息的融合会在救灾决策中发挥更大的作用.     

莱芜市征地拆迁的实践与探索

莱芜市国土资源局市区分局征地拆迁过程中,严格规范征地拆迁程序,及时按要求进行安置补偿,并建立了征地拆迁矛盾纠纷排查调处机制。但仍存在失地农民的社会保障制度不完善、土地级差收益和征地补偿价格差异大、地面附着物补偿标准不全面而且偏低、被征地农民安置欠缺等问题。根据莱芜市工作现状进行调研分析,并对今后工作开展进行了探讨,提出加大征地拆迁政策宣传力度,积极探索和改进土地征用补偿方式,实行留地政策,拓宽失地农民安置途径等建议。     

近45年山西省冷暖期转折中关键的2年

利用山西省68个气象站1961年-2005年的年平均气温资料,研究了近45年来山西省的气温变化。结果表明：年平均气温最高出现在1999年,次高出现在1998年,最低出现在1984年,这3年的气温距平均超过了2倍标准差的异常标准;山西20世纪80年代和70年代相比气温略有降低;从距平我们只能粗略地分析出气温的冷暖时段,而采用累积距平方法则清楚地显示出,1986年和1996年是山西近45年气温出现转折的关键2年,以此为界将山西省45a的气温变化较为客观地划分为3个时段。     

对吕宋海峡深水瀑布的重新认识

On the basis of the latest version of a U.S. Navy generalized digital environment model(GDEM-V3.0) and World Ocean Atlas(WOA13), the hydraulic theory is revisited and applied to the Luzon Strait, providing a fresh look at the deepwater overflow there. The result reveals that:(1) the persistent density difference between two sides of the Luzon Strait sustains an all year round deepwater overflow from the western Pacific to the South China Sea(SCS);(2) the seasonal variability of the deepwater overflow is influenced not only by changes in the density difference between two sides of the Luzon Strait, but also by changes in its upstream layer thickness;(3) the deepwater overflow in the Luzon Strait shows a weak semiannual variability;(4) the seasonal mean circulation pattern in the SCS deep basin does not synchronously respond to the seasonality of the deepwater overflow in the Luzon Strait.Moreover, the deepwater overflow reaches its seasonal maximum in December(based on GDEM-V3.0) or in fall(October–December, based on the WOA13), accompanied by the lowest temperature of the year on the Pacific side of the Luzon Strait. The seasonal variability of the deepwater overflow is consistent with the existing longest(3.5 a) continuous observation along the major deepwater passage of the Luzon Strait.     

元谋干热河谷冲沟区植被对微地形的响应

微地形是影响植被分布格局及多样性的重要因素。在元谋干热河谷冲沟区采集了1 236组"土壤-坡度-坡向-植被盖度-物种多样性"数据,运用统计学方法研究了坡度和坡向这两个地形因子对干热河谷植被盖度及其多样性的影响。结果表明:在元谋干热河谷冲沟区,植被盖度呈现出随坡度增大而减小的趋势,变性土区域活跃性冲沟坡面上有无植被生长的临界坡度是50°,而燥红土区域稳定性冲沟的临界坡度为65°;受人类活动影响强烈的沟坡区植被生长的临界坡度是45°,影响较轻微的近自然状态沟坡区的临界坡度是65°;植被盖度分布和植被种类的优势方向同为东北向,平均盖度为40%,西北向为28%,西南为20%,东南为21%;植被种类东北向平均为1.8,西北向为1.4.西南向为1.0,东南向为0.5。研究元谋干热河谷典型立地条件下植被对冲沟微地形条件的响应,可以为本区生态恢复提供科学指导。     

A Climatic Sequence Stratigraphic Model in the Terrestrial Lacustrine Basin: A Case Study of Green River Formation,Uinta Basin,USA

In recent years, with the development of terrestrial sequence stratigraphy, more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are preferred by researchers. Under the guidance of the theory of sequence stratigraphy, the findings of this paper indicate that climate is a major factor controlling the formation of the fourth-order sequence, based upon the study of the sequence stratigraphy in the Green River Formation of the Uinta basin in the USA. It also divides the fourth-order sequence in the terrestrial lacustrine basin into two system tracts: the wet (rising) half-cycle and the dry (falling) half-cycle, establishing a new-style fourth-order sequence stratigraphic model for the terrestrial lacustrine basin, that is, the climate-genetic sequence stratigraphic model. As a result, the theory of sequence stratigraphy is greatly enriched.     

水汽场中气液态水质量比的确定方法

包气带中裂隙岩体含水量无法用仪器或者实验的方法获取,也无法用理论方法计算,而这部分水对生态复绿和文物保护等的影响不容忽视。为了解决这一问题,确定岩体内气液态水的质量比（α）是关键。在岩体、气态水和液态水组成的开放系统中,当系统内相对湿度达到100%,系统达到局域平衡态。根据热动力学平衡理论,此时系统内气液态水的密度和质量都相等,即液态水和气态水的质量之比为一常数。因此,为了求取α值,文章设计了室内试验,通过对有效试验数据的分析,获取计算α经验公式。试验研究表明:质量比α跟温度t呈指数函数关系;当气态水达到饱和时,液态水的质量远大于气态水的质量。此研究不仅为定量评价包气带中岩体内水汽含量提供一种计算方法,同时对探讨包气带中岩体内气液态水转化规律具有十分重要的参考价值。     

Applied Sequence Stratigraphy in Nonmarine Basin of China

INTRODUCTIONSequence stratigraphy, an efficient technique for both thebasin analysis and the prediction of hidden oil and gas reser-voir, was traced to seismic stratigraphy founded in l977, andnow has become a separate academic discipline after years ofamendments. In the 26th AAPG, the sedimentary se(1[I(>ncewas defined and the seismic stratigraphy technique was estaI)-lished to characterize and interpret seismic reflection scction.The sequence stratigraphy was emphasized to confirm and…