Satellite-derived rainfall thresholds for landslide early warning in Bogowonto Catchment,Central Java,Indonesia     

《International Journal of Applied Earth Observation and Geoinformation》2020

Satellite rainfall products for landslide early warning prediction have been spotlighted by several researchers, in the last couple of decades. This study investigates the use of TRMM and ERA-Interim data, for the determination of rainfall thresholds and the prediction of precipitation, respectively, to be used for landslide early warning purposes at the Bogowonto catchment, Central Java, Indonesia. A landslide inventory of 218 landslides for the period of 2003–2016 was compiled, and rainfall data were retrieved for the landslide locations, as given by 6 ground stations, TRMM, and ERA-Interim data. First, rainfall data from the three different sources was compared in terms of correlation and extreme precipitation indices. Second, a procedure for the calculation of rainfall thresholds for landslide occurrence was followed consisting of four steps: i) the TRMM-based rainfall data was reconstructed for selected dates and locations characterized by landslide occurrence and non-occurrence; ii) the antecedent daily rainfall was calculated for 3, 5, 10, 15, 20 and 30 days for the selected dates and locations; iii) two-parameter daily rainfall-antecedent rainfall thresholds were calculated for the aforementioned dates; after analysis of the curves the optimum number of antecedent rainfall days was selected; and (iv) empirical rainfall thresholds for landslide occurrence were determined. The procedure was repeated for the entire landslide dataset, differentiating between forested and built-up areas, and between landslide occurrence in four temporal periods, in relation to the monsoon. The results indicated that TRMM performs well for the detection of very heavy precipitation and can be used to indicate the extreme rainfall events that trigger landslides. On the contrary, as ERA-Interim failed to detect those events, its applicability for LEWS remains limited. The 15-day antecedent rainfall was indicated to mostly affect the landslide occurrence in the area. The rainfall thresholds vary for forested and built-up areas, as well as for the beginning, middle and end of the rainy season.  相似文献   

蝗虫遥感监测预警研究现状与展望   总被引：3，自引：0，他引：3  

黄文江  董莹莹  赵龙龙  耿芸  阮超  张弼尧  孙忠祥  张寒苏  叶回春  王昆 《遥感学报》2020,24(10):1270-1279

气候变化背景下全球蝗灾日益肆虐，为支撑虫害及时精准防控，迫切需要开展大面积蝗虫动态监测预警研究。本文从蝗虫生境遥感监测、蝗虫发生动态遥感预警，以及蝗灾遥感损失评估3个方面介绍了当前研究现状，并指出当前存在的问题主要包括3个方面：蝗虫监测预警的时空分辨率较粗，无法精准定位虫害热点发生区和重点危害区；遥感虫害响应机制与虫害生物学扩散模型耦合度较低，导致模型时空普适性较差；缺乏高时空精度的虫害监测预警空间信息服务产品。因此，当前急需发展面向全球、洲际、全国、区域的多尺度、长时序、高精度虫害精准监测预警平台。通过建立时空精细尺度的虫害监测预警指标体系，研制遥感机制与虫害生物学机理深度耦合的高精度预测预报模型，发布多尺度高时频的虫害监测预警空间信息产品和服务，以实现海量数据的自动入库和智能存储、多层次模型的快速调用和高性能计算、虫害测报产品的在线生产和可视化服务。建立从数据到模型到产品服务的全链路，从而切实提升全球应对重大迁飞性虫害的智能化水平，为保障粮食安全、维护区域稳定和可持续发展提供科技支撑。  相似文献   

SEDIMENTARY PETROLOGY     

《Abstract of Chinese Geological Literature》2014,(3)

正20141430 Chen Ji(Key Laboratory of Petroleum Resources,Chinese Academy of Sciences,Lanzhou 730000,China);Shi Ji’an Sedimentary Facies and Models for the Palaeogene-Neogene Deposits on the Northern Margin of the Qaidam Basin,Qinghai Province(Sedimentary Geology and Tethyan Geology,ISSN1009-3850,CN51-1593/P,33(3),2013,p.16-26,14 illus.,16 refs.)  相似文献   

ECONOMIC GEOLOGY     

《Abstract of Chinese Geological Literature》2014,(4)

正20142114Lin Quansheng(China University of Geosciences,Bejing 100083,China)On the Geologic Characteristics and Economic Significance of the Cambrian Lintian Group in Fujian Province(Geology of Fujian,ISSN1001-3970,CN35-1080/P,32(4),2013,p.264-273,2illus.,2tables,6refs.)  相似文献   

Petrography of Late Cambrian to Middle Ordovician radiolarian chert in Kazakhstan with special reference to the emergence of benthic animals in the pelagic realm     

Yoshitaka Kakuwa  Olga I. Nikitina 《Sedimentology》2020,67(5):2764-2776

Upper Cambrian to Middle Ordovician radiolarian chert successions from Kazakhstan were studied to clarify the history of the emergence of benthic animals in ocean floor sediments. Radiolarian tests and clay were deposited for a period of 30 Myr without experiencing an influx of continent-derived coarse clastic materials. Red, grey and black cherts of the Upper Cambrian to the upper mid-Darriwilian are thinly laminated, and no trace of benthic animal activity is recognized in that time interval. Bioturbation structures and burrow traces in mid-Darriwilian stage red chert in Kazakhstan suggest that benthic animals colonized the location where radiolarian chert formed, but that there was a significant delay in colonization when compared with similar reported occurrences in Australia and Canada.  相似文献   

The Early Permian Woniusi Flood Basalts from the Baoshan Terrane, SW China: Petrogenesis and Geodynamic Implications     

CAO Jun  ZHANG Gaizhi  WANG Xuan  CHEN Jun 《《地质学报》英文版》2020,94(6):2091-2114

The Woniusi flood basalts from the Baoshan terrane, SW China, represent a signi?cant eruption of volcanic rocks which were linked to the Late Paleozoic rifting of the Cimmeria from the northern margin of East Gondwana. However, the precise mechanism for the formation and propagation of the rifting is still in debate. Here we report 40Ar/39Ar dating, whole-rock geochemistry, and Sr–Nd–Pb isotopes for the Woniusi basalts from the Baoshan terrane of SW China, with the aim of assessing if a mantle plume was related to the formation of the continent Cimmeria. 40Ar/39Ar dating of the Woniusi basalts yielded ages of 279.3 ± 1.1 Ma and 273.9 ± 1.5 Ma, indicating they were emplaced during the Early Permian. Whole-rock geochemistry shows that these basalts have subalkaline tholeiitic af?nity, low TiO2 (1.2–2.2 wt%), and fractionated chondrite-normalized LREE and nearly ?at HREE patterns [(La/Yb)N = 2.86–5.77; (Dy/Yb)N = 1.21–1.49] with noticeable negative Nb and Ta anomalies on the primitive mantle-normalized trace element diagram. The ?Nd(t) values (?4.76 to +0.92) and high (206Pb/204Pb)i (18.40?18.66) along with partial melt modeling indicates that the basalts were likely derived from a sub-continental lithospheric mantle (SCLM) source metasomatized by subduction-related processes. On the basis of a similar emplacement age to the Panjal basalts and Qiangtang mafic dykes and flood basalts in the Himalayas, combined with a tectonic reconstruction of Gondwana in the Early Permian, we propose that the large-scale eruption of these basalts and dykes was related to an Early Permian mantle plume that possibly initiated the rifting on the northern margin of East Gondwana.  相似文献   

华南寒武纪早期刺胞动物演化框架     

韩健  郭俊锋  欧强  宋祖晨  刘平  郝文静  孙洁  王星 《地学前缘》2020,27(6):67-78

刺胞动物是华南寒武纪早期海洋生态系统的重要组成部分,针对这类化石的研究有助于深入了解寒武纪多幕式爆发事件。本文主要根据寒武纪早期扬子板块陕南宽川铺生物群、湖北岩家河生物群以及澄江生物群产出的刺胞动物,探讨刺胞动物在寒武纪早期的演化框架,取得了以下初步认识。截至目前,所发现的寒武纪早期刺胞动物绝大多数都属于水母超纲,珊瑚纲的化石记录在寒武系幸运阶、第二阶保存较为罕见。其中寒武系幸运阶刺胞动物的化石记录全部属于底栖类型,体型小,且具有多种类型的身体辐射对称形式,绝大多数类型可以确定属于直接发育。第二阶刺胞动物仍以底栖固着类型为主,体形增大,仅见两、四辐射对称形式;而寒武系第三阶刺胞动物仍有底栖固着类型,但游泳的水母开始出现,体型增大明显,代表水母冠群的出现,以及世代交替的复杂生命周期的正式建立。从幸运阶到第三阶刺胞动物体型明显增大,可能与海水氧气含量增加有关。在寒武纪大爆发的背景下,刺胞动物的分异度和丰度在寒武系幸运阶就已经达到顶峰,然后在第二阶、第三阶开始衰减,这种变化可能与两侧对称动物辐射演化有关。华南刺胞动物的化石记录表明,寒武纪大爆发并非纯粹的一幕式爆发,其中充斥着一系列生物群的替代甚至灭绝事件。  相似文献   

Pseudofrenelopsis fossils from Cretaceous gypsum beds in Guixi,Jiangxi Province,China and their geological significance     

Bainian Sun  Jing Dai  Yongdong Wang  Hui Jia  Defei Yan  Zikun Jiang 《Island Arc》2011,20(1):43-56

Compressed fossil plants were found in the gypsum beds of the Zhoujiadian Formation in Guixi City, Jiangxi Province, China. The cuticular features of two species of Pseudofrenelopsis (Cheirolepidiaceae) were examined by scanning electron microscopy in this study: Pseudofrenelopsis papillosa Cao ex Zhou and Pseudofrenelopsis guixiensis Bainian Sun et Dai, sp. nov. A detailed analysis of the internode epidermis, and the adaxial and abaxial leaf cuticles of the two species, was performed, extending our knowledge of the morphological and anatomical characteristics of the extinct Pseudofrenelopsis. A new species, Pseudofrenelopsis guixiensis sp. nov., is proposed based upon comparison of its cuticular features. It differs from previously published species in that it has hairs on the abaxial surfaces of its leaves, sometimes shares subsidiary cells on the surfaces of internodes, lacks a hypodermis, and has no papillae on its epidermal cells. Because the distribution of fossil Pseudofrenelopsis is restricted to the Lower Cretaceous, the Early Cretaceous age of the Zhoujiadian Formation is affirmed. The fossils of Pseudofrenelopsis show obvious xeromorphic characteristics, such as apparent thickening of the cuticles, subsidiary cells with obvious papillae, and anticlinal walls with strong cutinization, and they are found associated with gypsum beds and close to red beds. All of these features indicate an arid climate.  相似文献   

Lower crustal melting via magma underplating: Elemental and Sr–Nd–Pb isotopic constraints from late Mesozoic intermediate–felsic volcanic rocks in the northeastern North China Block     

CHAOWEN LI  FENG GUO  WEIMING FAN 《Island Arc》2011,20(4):477-499

Ar–Ar dating, major and trace element analyses, and Sr–Nd–Pb isotope results of two groups of Lower Cretaceous (erupted at 126 and 119 Ma, respectively) intermediate–felsic lava from the northeastern North China Block (NCB) suggest their derivation from melting of mixtures between the heterogeneous lower crust and underplated basalts. Both groups exhibit high‐K calc‐alkaline to shoshonitic affinities, characterized by light rare earth element (LREE) and large ion lithophile element (LILE) enrichment and variable high field strength element (HFSE, e.g. Nb, Ta and Ti) depletion, and moderately radiogenic Sr and unradiogenic Nd and Pb isotopic compositions. Compared with Group 2, Group 1 rocks have relatively higher K₂O and Al₂O₃/(CaO + K₂O + Na₂O) in molar ratio, higher HFSE concentrations and lower Nb/Ta ratios, and higher Sr–Nd–Pb isotope ratios. Group 1 rocks were derived from a mixture of an enriched mantle‐derived magma and a lower crust that has developed radiogenic Sr and unradiogenic Nd and Pb isotopic compositions, whereas the Group 2 magmas were melts of another mixture between the same mantle‐derived component and another type of lower crust having even lower Sr, Nd, and Pb isotopic ratios. Shift in source region from Group 1 to Group 2 coincided with a change in melting conditions: hydrous melting of both the underplated basalt and the lower crust produced the earlier high‐Nb and low‐Nb/Ta melts with little or no residual Ti‐rich phases; while the younger low‐Nb and high‐Nb/Ta magmas were melted under a water‐deficient system, in which Ti‐rich phases were retained in the source. Generation of the two groups of intermediate–felsic volcanic rocks was genetically linked with the contemporaneous magma underplating event as a result of lithospheric thinning in the eastern NCB.  相似文献   

二连盆地早燕山期构造体制及原型盆地推测   总被引：2，自引：0，他引：2  

崔永谦  童亨茂  李先平  刘震  张洪波  杜长江 《地质学报》2011,85(8):1265-1273

本文在已有区域地质调查成果的基础上,通过钻井资料分析和三维地震资料的构造解析,确定二连盆地区及周缘侏罗系的分布存在两种型式:“叠合型”和“非叠合型”,其中前者分布在二连盆地区内;后者分布在盆地北部区域(以乌里雅思太凹陷为代表)和盆地周缘的露头区,并受“三纵四横”构造格架的控制.二连盆地区早燕山期处在南北向挤压和滨太平洋...  相似文献