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81.
在DOM数据生产中,山地、高山地数据一直以来都是重点和难点。本文分析了高山地影像数据的特点,提出一种与山地、高山地数据相适应的处理方式。最后基于CIPS软件,按需求设计对应的软件处理流程,并使用满足实验要求的高山地影像数据,对这种方式加以实现和验证。 相似文献
82.
无人机低空遥感是近年来新兴的一种快速获取灾情信息的手段,如何利用无人机高分影像构建滑坡灾害解译模型是实现快速自动解译滑坡的关键。针对该问题,对比了多种影像特征提取方法,将迁移学习(TL)特征和支持向量机(SVM)引入到构建滑坡灾害自动解译模型中,提出了一种TL支持下的高分影像滑坡灾害解译模型。选取5·12汶川地震及4·20芦山地震系列无人机影像构建了滑坡灾害样本库并进行了实验,TL特征方法整体分类准确度ACC为95%,ROC达到0.98,识别准确率达到97%。结果表明,所提方法可用于高分影像滑坡自动解译,同时可用于大面积高分影像中快速山地滑坡灾害定位及检测。 相似文献
83.
东昆仑祁漫塔格山地区夏日哈木镍矿床矿物学特征 总被引:3,自引:0,他引:3
青海夏日哈木是近年来新发现的超大型镍矿床,大地构造位置处于东昆仑造山带之东昆中花岗—变质杂岩带的隆起区,成矿与镁铁质—超镁铁质小侵入体有关,属岩浆深部熔离贯入型。矿体呈透镜状、似层状,主要产于辉石岩、橄辉岩和苏长岩中;矿石为块状、准块状、海绵陨铁状、浸染状、细脉状和斑杂状构造,粒状结构、交代结构和固溶体分离结构等。矿石金属矿物主要为磁黄铁矿、镍黄铁矿和黄铜矿,含少量和微量紫硫镍矿、马基诺矿、铬铁矿、磁铁矿、黄铁矿、闪锌矿、辉铋矿、钛铁矿和自然铋等;脉石矿物主要有斜方辉石、橄榄石、普通辉石、基性斜长石、镁铁闪石、直闪石、滑石、蛇纹石等。文中对夏日哈木和金川我国两个超大型镍矿的主要地质特征作了对比;与世界上主要同类型硫化物铜镍矿床相比较,夏日哈木镍矿具有不少独特的特征,如其成岩成矿时代相对较年轻,矿石中铜的品位较低、亏损铂族元素等。 相似文献
84.
采用NCEP/NCAR日平均再分析资料,对冬季热带外低频振荡(大气角动量收支及地形力矩)与AO(Arctic Oscillation)指数进行计算,通过功率谱和统计分析发现,它们都存在30~60 d的周期,大气角动量收支与山脉力矩的变化为正相关,且显著响应AO变化。通过动力学诊断分析初步认为,北半球两大地形的山脉力矩作用于纬向大气角动量,副热带纬向西风发生变化,改变南北西风偶极子结构,使得AO产生变化,而且在两大地形中以喜马拉雅山脉地形作用为主。通过对喜马拉雅山脉地区的动力学诊断发现,在高(低)AO指数阶段,喜马拉雅山脉地区激发准定常行星波并作用于副热带西风,导致副热带西风偏弱(偏强),高纬西风偏强(偏弱),因而AO偏强(偏弱),平流层极涡偏强(偏弱),极涡强(弱)中心偏向东北亚。 相似文献
85.
During the Late Paleozoic, the Gondwana supercontinent was affected by multiple glacial and deglacial episodes known as “The Late Paleozoic Ice Age” (LPIA). In Brazil, the evidence of this episode is recorded mainly by widespread glacial deposits preserved in the Paraná Basin that contain the most extensive record of glaciation (Itararé Group) in Gondwana. The Pennsylvanian to early Permian glaciogenic deposits of the Itararé Group (Paraná Basin) are widely known and cover an extensive area in southern Brazil. In the Doutor Pedrinho area (Santa Catarina state, southern Brazil), three glacial cycles of glacier advance and retreat were described. The focus of this article is to detail the base of the second glacial episodes or Sequence II. The entire sequence records a deglacial system tract that is represented by a proximal glacial grounding-line system covered by marine mudstones and shales associated with a rapid flooding of the proglacial area. This study deals with the ice proximal grounding-line systems herein interpreted according to lab model named plane-wall jet with jump. Detailed facies analysis allowed the identification of several facies ranging from boulder-rich conglomerates to fine-grained sandstones. No fine-grained deposits such as siltstone or shale were recorded. According to this model, the deposits are a product of a supercritical plane-wall outflow jet that changes to a subcritical jet downflow from a hydraulic jump. The hydraulic jump forms an important energy boundary that is indicated by an abrupt change in grain size and cut-and-fill structures that occur at the middle-fan. The sedimentary facies and facies associations show a downflow trend that can be subdivided into three distinct stages of flow development: (1) a zone of flow establishment (ZFE), (2) a zone of transition (ZFT), and (3) an established zone (ZEF). The proximal discharge is characterized by hyperconcentrated-to-concentrated flow due to the high energy and sediment-laden nature of the flows. At the transitional zone, a hydraulic jump produces a rapid shift of conglomeratic to sandy facies with associated scour features. Towards the distal zones, the jet detaches to originate a vertical turbulent jet characterized by more diluted flows. Discussion of fan facies and architecture within a framework of jet-efflux dynamics provides an improved understanding of grounding-line fans systems that produce coarse-grained strata commonly enclosed by fine-grained rocks. The results have clear implication in terms of prediction of facies tract and geometry of oil and gas reservoirs deposited under similar conditions. And also can be useful to identifying the position of a glacial terminus through time. 相似文献
86.
闹阳坪锌萤石矿床位于北大巴山逆冲推覆褶皱带平利隆起东侧,为该区首次发现的受构造裂隙控制的气水–热液型锌萤石矿床。本文从矿区断裂入手,通过对该区矿床地质、断裂特征、矿体特征的研究,总结了该区断裂的演化序列及其对成矿的控制机制与规律。认为NW-SE向断裂组是矿区的主要控矿构造,矿区断裂变形发育演化序列为晚印支–早燕山期形成近EW向断裂F1,早燕山期形成NW-SE向断裂F7和NE-SW向断裂F4,随后的右行走滑作用叠加有张扭性应力,形成有利于成矿热液运移充填成矿的张扭性右行走滑断裂。并明确了成矿期应变椭球体,恢复了成矿期主压应力方向为NNW向(340°~350°)。在此基础上,预测平面上闹阳坪矿区F7与F8断裂之间为下一步找矿重点地段,剖面上K3萤石矿体下伏北东方向可能存在隐伏矿体。 相似文献
87.
88.
The simulation of LUCC based on Logistic-CA-Markov model in Qilian Mountain area,China 总被引:2,自引:0,他引:2
The Qilian mountain area was examined for using the Logistic-CA-Markov coupling model combined with GIS spatial analyst technology to research the transformation of LUCC, driving force system and simulate future tendency of variation. Results show that:(1) Woodland area decreased by 12.55%, while grassland, cultivated land, and settlement areas increased by 0.22%, 7.92%, and 0.03%, respectively, from 1986 to 2014. During the period of 1986 to 2000, forest degradation in the middle section of the mountain area decreased by 1,501.69 km~2. Vegetation cover area improved, with a net increase of grassland area of 38.12 km~2 from 2000 to 2014.(2) For constructing the system driving force, the best simulation scale was 210m×210m. Based on logistic regression analysis, the contribution(weight) of composite driving forces to land use and cover change was obtained, and the weight value was more objectively compared with AHP and MCE method.(3) In the natural scenarios, it is predicted that land use and cover distribution maps of Qilian mountain area in 2028 and 2042, and the Lee-Sallee index test was adopted. Over the next 27 years(2015–2042), farmland, woodland, grassland, settlement areas show an increasing trend, especially settlements with an obvious change of 0.56%. The area of bare land will decrease by 0.89%. Without environmental degradation, tremendous structural change of LUCC will not occur, and typical characteristic of the vertical zone of the mountain would remain. Farmland and settlement areas will increase, but only in the vicinity of Qilian and Sunan counties. 相似文献
89.
以2014—2015年的GF 1为主、少量OLI影像为基础,参考第二次中国冰川目录等文献资料,修编完成青海省和西藏自治区两省区的现代冰川编目,查明青藏两省区目前共有冰川24 796条,总面积约2624×104 km2,约占青藏两省区区域面积的137%,冰川储量为2027×103~2121×103 km3。调查区冰川数量以面积<10 km2、冰川面积介于10~100 km2之间的冰川为主,其中面积<10 km2的冰川有19 983条,占总数量的8059%,面积介于10~100 km2之间的冰川面积为11 96240 km2,占总面积的4559%;面积最大的中锋冰川的面积达23737 km2。调查区内的山系(高原)均有冰川分布,念青唐古拉山冰川数量最多,其次是喜马拉雅山和冈底斯山,这3座山系冰川数量占调查区内冰川总数量的6333%;念青唐古拉山、喜马拉雅山和昆仑山的冰川面积和冰储量位列前3位,其冰川面积和冰储量分别占总数的6809%和7344%;然而昆仑山和羌塘高原的单条冰川的平均面积大于念青唐古拉山和喜马拉雅山的平均面积。从冰川海拔分布来看,海拔5 000~6 500 m之间是冰川集中发育区域,约占调查区冰川数量和冰川总面积的85%以上。调查区的冰川在各流域的分布差异显著,恒河流域是冰川分布数量最多、面积最大的一级外流区,其数量占冰川总量的47%以上,面积占总面积的52%以上;青藏高原内陆流域的冰川数量、面积次之,其冰川数量占总数量的21%,面积占总面积的24%以上,并且内流区单条冰川的平均面积略大于外流区的平均面积。总体上,西藏的冰川数量、面积和冰储量分别占西藏和青海两省区的8492%、8492%、8668%,单条冰川的平均面积两省区相近。 相似文献
90.