中国主要经济区的近期气候变化特征评估     

张学珍  郑景云  郝志新 《地理科学进展》2020,39(10):1609-1618

论文在中国《第三次气候变化国家评估报告》基础上,根据2012年以来的最新研究成果和中国气候公报,综合评估了环渤海经济区、长江经济带、华南经济圈和东北经济区的近期气候变化特征。主要结论有：① 1961—2018年,环渤海经济区、长江经济带、华南经济圈和东北经济区的平均气温上升趋势分别达0.35 ℃/10 a、0.20 ℃/10 a、0.20 ℃/10 a和0.33 ℃/10 a;尽管在1998—2014年间这些区域均出现了增暖趋缓特征,但除东北经济区外,环渤海经济区、长江经济带和华南经济圈均在2014年之后突破了其前最暖年的年均气温记录。② 1961—2018年各经济区(圈、带)的降水趋势变化虽均低于1 mm/10 a,但其间年际和年代际波动显著;2012—2018年降水虽总体偏多,但时空差异较大,其中东北经济区2013年和长江经济带2016年降水为1961年以来最多,而辽宁2014年降水却为1961年以来最少。③ 2014—2018年,各经济区(圈、带)最高气温超历史极值或极端阈值(发生概率≤10%的分位值)的极端高温事件频发,同时环渤海和东北经济区的区域性跨季连旱和极端特大暴雨等事件的发生频率增多,长江经济带暴雨日数偏多,华南经济区受台风影响呈加重态势;长江经济带和东北经济区在增暖同时也出现了多次大范围的极端低温事件。  相似文献   

地方政府土地出让干预对区域工业碳排放影响的对比分析——以中国8大经济区为例     

王博  吴天航  冯淑怡 《地理科学进展》2020,39(9):1436-1446

探讨不同区域地方政府干预对碳排放的影响差异,对于中国推进碳减排战略、协调区域经济社会发展具有重要意义。鉴于此,论文基于地方政府土地出让的视阈,以中国8大经济区为研究对象,有机耦合STIRPAT模型与CKC模型,构建形成STIRPAT拓展模型,并使用2007—2016年中国28个省(市、自治区)的工业面板数据,对比考察8大经济区政府土地出让干预对区域碳排放的影响差异。结果表明:不同经济区的地方政府土地出让干预对区域碳排放的影响存在显著差异。其中,同为CKC“倒N”型的北部沿海、南部沿海、长江中游经济区,其政府土地出让干预对区域碳排放的影响呈现出北部沿海经济区为负、南部沿海经济区为正、长江中游经济区无显著影响的差异效果;同为CKC“倒U”型的东北、西南和西北经济区,其政府土地出让干预对区域碳排放的影响,东北和西南经济区都显著为负,西北经济区未表现出显著影响;同为CKC“U”型的东部沿海和黄河中游经济区,其政府土地出让干预对碳排放也呈现出前者为负、后者为正的相反影响。研究结果可为制定碳减排差别化政策、协调区域可持续发展提供参考。  相似文献   

Statistical characterization of frost zones: Case of tea freeze damage in the Kenyan highlands     

《International Journal of Applied Earth Observation and Geoinformation》2020

Frequent frost occurrences in the Kenyan highlands have had devastating effects on agricultural productivity. With inadequate management systems to mitigate the impacts, farmers have often had to bear the burden of losses resulting from frost damage. While agriculture in Kenya remains dependent on weather and climate, the agricultural economy of Kenya continues to suffer, underscoring the need for building local knowledge as basis for development of early warning systems. The current paper attempts to delineate frost zones by statistically characterizing them based on known risk factors related to topography (elevation, convexity, aspect, upslope flow length) and Land Surface Temperature (LST) derived from Moderate Resolution Imaging Spectroradiometer (MODIS). Through binary logistic regression, a logistic regression model was developed utilizing observation data (frost occurrence and non-occurrence) as a binary dependent variable to estimate the probability of frost occurrence. Assuming a 0.5 probability cut-off threshold between frost occurrence and non-occurrence, an overall accuracy of 81% with area under Receiver Operating Characteristics (ROC) Curve of 0.88 was obtained. No evidence of lack of model fit was detected. This model outperforms the currently operational model that utilizes MODIS LST alone to detect frost zones in the Kenyan tea plantations. It provides an improved method for effective delineation of frost zones by incorporating local topographic characteristics.  相似文献   

Terrane sutures in the Maine Appalachians,USA and adjacent areas     

Stephen G. Pollock 《Geological Journal》1993,28(1):45-67

Terrane sutures in the Maine Appalachians and adjacent areas are recognized as melange dominated, deformed accretionary prisms of Ordovician age, and as a broad synmetamorphic transcurrent fault zone of probable Late Silurian-Early Devonian age. Although the accretionary prisms are associated with present day aeromagnetic and Bouguer gravity anomalies, they are probably not associated with present day crustal penetrating boundaries. The geology of the accretionary prisms indicates subduction-obduction dominated regimes during which (1) the Gander and Boundary Mountain (Dunnage) terranes amalgamated and (2) the composite Boundary Mountain-Gander terrane accreted to the Laurentian margin. The Penobscottian orogeny produced and deformed the older of the two accretionary prisms. This accretionary prism indicates that the Penobscottian was a continuous or perhaps diachronous event which spanned the late Cambrian to early Late Ordovician. The younger accretionary prism was produced and deformed during the Taconian orogeny during late Middle to early Late Ordovician. Initial deformation of this accretionary prism may have overlapped the waning stages of the Penobscottian. Portions of the Taconian arc locally overlie the Penobscottian accretionary prism. A synmetamorphic fault zone lies within Precambrian(?) to Ordovician(?) bimodal metavolcanic and metapelitic rocks assigned here to the Avalon terrane. This zone is several kilometres wide and is interpreted to be the postsubduction suture between the Avalon and Gander terranes, and may, in part, represent a fossil transform fault system. The fault zone contains phyllonites as well as shear zones which generally record dextral motion. The phyllonites were previously interpreted as a stratigraphic unit, whereas the shear zones span or are contained within mappable compositional units. Formation of and movement along these phyllonites and shear zones ceased before the intrusion of Early Devonian plutons. Not all faults in south-western Maine are related to the suture. Younger dip and/or strike-slip and thrust faults are approximately parallel to, or may lie within, the older shear zones and they complicate the recognition of the older faults.  相似文献   

Normal fault growth influenced by basement fabrics: The importance of preferential nucleation from pre‐existing structures     

Luca Collanega  Katherine Siuda  Christopher A.‐L. Jackson  Rebecca E. Bell  Alexander J. Coleman  Antje Lenhart  Craig Magee  Anna Breda 《Basin Research》2019,31(4):659-687

Reactivation of pre‐existing intra‐basement structures can influence the evolution of rift basins, yet the detailed kinematic relationship between these structures and overlying rift‐related faults remains poorly understood. Understanding the kinematic as well as geometric relationship between intra‐basement structures and rift‐related fault networks is important, with the extension direction in many rifted provinces typically thought to lie normal to fault strike. We here investigate this problem using a borehole‐constrained, 3D seismic reflection dataset from the Taranaki Basin, offshore New Zealand. Excellent imaging of intra‐basement structures and a relatively weakly deformed, stratigraphically simple sedimentary cover allow us to: (a) identify a range of interaction styles between intra‐basement structures and overlying, Plio‐Pleistocene rift‐related normal faults; and (b) examine the cover fault kinematics associated with each interaction style. Some of the normal faults parallel and are physically connected to intra‐basement reflections, which are interpreted as mylonitic reverse faults formed during Mesozoic subduction and basement terrane accretion. These geometric relationships indicate pre‐existing intra‐basement structures locally controlled the position and attitude of Plio‐Pleistocene rift‐related normal faults. However, through detailed 3D kinematic analysis of selected normal faults, we show that: (a) normal faults only nucleated above intra‐basement structures that experienced late Miocene compressional reactivation, (b) despite playing an important role during subsequent rifting, intra‐basement structures have not been significantly extensionally reactivated, and (c) preferential nucleation and propagation of normal faults within late Miocene reverse faults and folds appears to be the key genetic relationship between contractionally reactivated intra‐basement structures and rift‐related normal faults. Our analysis shows that km‐scale, intra‐basement structures can control the nucleation and development of newly formed, rift‐related normal faults, most likely due to a local perturbation of the regional stress field. Because of this, simply inverting fault strike for causal extension direction may be incorrect, especially in provinces where pre‐existing, intra‐basement structures occur. We also show that a detailed kinematic analysis is key to deciphering the temporal as well as simply the spatial or geometric relationship between structures developed at multiple structural levels.  相似文献   

Seismic‐stratigraphic constraints on the age of the Faroe Islands Basalt Group,Faroe–Shetland region,Northeast Atlantic Ocean     

Jana lavsdttir  Martyn S. Stoker  Lars O. Boldreel  Morten Sparre Andersen   luva R. Eidesgaard 《Basin Research》2019,31(5):841-865

Lower Palaeogene extrusive igneous rocks of the Faroe Islands Basalt Group (FIBG) dominate the Faroese continental margin, with flood basalts created at the time of breakup and separation from East Greenland extending eastwards into the Faroe‐Shetland Basin. This volcanic succession was emplaced in connection with the opening of the NE Atlantic; however, consensus on the age and duration of volcanism remains lacking. On the Faroe Islands, the FIBG comprises four main basaltic formations (the pre‐breakup Lopra and Beinisvørð formations, and the syn‐breakup Malinstindur and Enni formations) locally separated by thin intrabasaltic sedimentary and/or volcaniclastic units. Offshore, the distribution of these formations remains ambiguous. We examine the stratigraphic framework of these rocks on the Faroese continental margin combining onshore (published) outcrop information with offshore seismic‐reflection and well data. Our results indicate that on seismic‐reflection profiles, the FIBG can be informally divided into lower and upper seismic‐stratigraphic packages separated by the strongly reflective A‐horizon. The Lower FIBG comprises the Lopra and Beinisvørð formations; the upper FIBG includes the Malinstindur and Enni formations. The strongly reflecting A‐horizon is a consequence of the contrast in properties of the overlying Malinstindur and underlying Beinisvørð formations. Onshore, the A‐horizon is an erosional surface, locally cutting down into the Beinisvørð Formation; offshore, we have correlated the A‐horizon with the Flett unconformity, a highly incised, subaerial unconformity, within the juxtaposed and interbedded sedimentary fill of the Faroe‐Shetland Basin. We refer to this key regional boundary as the A‐horizon/Flett unconformity. The formation of this unconformity represents the transition from the pre‐breakup to the syn‐breakup phase of ocean margin development in the Faroe–Shetland region. We examine the wider implications of this correlation considering existing stratigraphic models for the FIBG, discussing potential sources of uncertainty in the correlation of the lower Palaeogene succession across the Faroe–Shetland region, and implications for the age and duration of the volcanism.  相似文献   

Extensional fault and fold growth: Impact on accommodation evolution and sedimentary infill   总被引：2，自引：2，他引：0  

Christopher Sb Serck  Alvar Braathen 《Basin Research》2019,31(5):967-990

Extensional faults and folds exert a fundamental control on the location, thickness and partitioning of sedimentary deposits on rift basins. The connection between the mode of extensional fault reactivation, resulting fault shape and extensional fold growth is well‐established. The impact of folding on accommodation evolution and growth package architecture, however, has received little attention; particularly the role‐played by fault‐perpendicular (transverse) folding. We study a multiphase rift basin with km‐scale fault displacements using a large high‐quality 3D seismic data set from the Fingerdjupet Subbasin in the southwestern Barents Sea. We link growth package architecture to timing and mode of fault reactivation. Dip linkage of deep and shallow fault segments resulted in ramp‐flat‐ramp fault geometry, above which fault‐parallel fault‐bend folds developed. The folds limited the accommodation near their causal faults, leading to deposition within a fault‐bend synclinal growth basin further into the hangingwall. Continued fold growth led to truncation of strata near the crest of the fault‐bend anticline before shortcut faulting bypassed the ramp‐flat‐ramp structure and ended folding. Accommodation along the fault‐parallel axis is controlled by the transverse folds, the location and size of which depends on the degree of linkage in the fault network and the accumulated displacement on causal faults. We construct transverse fold trajectories by tracing transverse fold hinges through space and time to highlight the positions of maximum and minimum accommodation and potential sediment entry points to hangingwall growth basins. The length and shape of the constructed trajectories relate to the displacement on their parent faults, duration of fault activity, timing of transverse basin infill, fault linkage and strain localization. We emphasize that the considerable wavelength, amplitudes and potential periclinal geometry of extensional folds make them viable targets for CO₂ storage or hydrocarbon exploration in rift basins.  相似文献   

近60a来新疆不同海拔气候变化的时空特征分析   总被引：1，自引：0，他引：1       下载免费PDF全文

张音  古丽贤·吐尔逊拜  苏里坦  刘迁迁 《干旱区地理》2019,42(4):822-829

全球变暖是当前全球气候变化研究的热点之一,新疆深居亚欧大陆内陆,地形气候复杂,探讨该区域气候变化与海拔的关系对全球气候变化研究具有重要的参考意义。基于1958—2017年新疆41个气象站的月和年平均气候数据,采用一元线性回归、Mann Kendall（M-K）趋势分析和突变检验等方法分析该地区气候变化的时空分布与海拔的关系。结果表明：1958—2017年新疆年均气温、年均降水量均呈上升趋势,但增加幅度具有时间和空间差异。在时间上,北疆四季平均气温增温幅度均大于南疆（冬季除外）,四季降水量增幅北疆大于南疆（夏季除外）;在空间上,北疆气温和降水的增幅均大于南疆。研究区各个站点气温呈现出南部高而北部低的空间格局,年均降水量北部多,南部低。各个站点气温倾向率总体随海拔增加而减少,年均降水量变化率随海拔升高而增加,在不同海拔带内部存在差异。综上所述,受全球气候变暖的影响,近60 a来新疆年均气温和年均降水量均呈上升趋势,尤其是北疆对全球气候变暖的响应较为敏感。  相似文献   

南海北部水合物富集区水道特征对比与成因分析     

付超  于兴河  董亦思  何玉林  梁金强  匡增桂 《海洋学报(英文版)》2019,38(3):103-113

天然气水合物作为现今乃至未来的重要清洁能源之一,其沉积环境和成矿条件的研究一直是国内外地质学家关注的热点问题,我国2007年、2013年及2015年已先后在神狐、和东沙海域多次成功钻获了天然气水合物实物样品。由此南海北部陆坡成为探讨天然气水合物沉积成因与成矿条件的重要试验区。然而,南海北部陆坡区的神狐、东沙及琼东南三个海域均有不同程度的天然气水合物发现,其各自的水深、沉积特征、气源成因及水合物成矿条件各有特点。本文利用地震沉积学原理,结合不同沉积相和沉积演化和古地貌、海平面变化和构造运动等因素,识别出不同类型的地震相。通过对比南海北部陆坡区域的水道系统的MTDs,认为其发育位置、展布和控制因素的不同影响了沉积展布。其中东沙区域位于近物源的上陆坡,神狐区域位于正常的缓陆坡区域,琼东南区域位于远离物源的海底平原区域。并且,水道系统可以分成侵蚀型,侵蚀-加积型和加积型,MTDs也可以分成头部拉张型,中部过渡型和趾部挤压型。  相似文献   

海洋主体功能区划与海洋功能区划关系研究     

王倩  郭佩芳 《海洋湖沼通报》2009,(4)

开展海洋主体功能区划与海洋功能区划的关系和衔接研究,是保障两者在我国海洋事业中充分发挥各自作用的基础.本文从编制及实施2个方面理顺海洋主体功能区划与海洋功能区划的关系,促进两者在实际工作中的相互结合.  相似文献