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1.
为论证小型无人机航测在大比例尺成图技术上的精度和可靠度,利用小型多旋翼高精度航测无人机拍摄测区影像,影像采集完成后,使用拼图软件输出数字正射影像DOM同时生成密集点云数据,最后用南方CASS软件绘制数字线划图,得到1∶1 000比例尺地形图。为了验证点位精度,选取36个地物特征点,以GPS-RTK测量数据作为真值与航测数据进行点位误差精度评定。结果表明:平面位置上,在X坐标方向最大误差为0.143 6 m,Y坐标方向最大误差为0.109 6 m,计算得到水平方向的点位中误差为±0.06 m;高程值最大差异为0.262 0 m,最小差异为0.002 m,高程中误差为±0.10 m,均符合1∶1 000地形图的规范要求。证明小范围大比例尺测绘中无人机航测代替GPS测量的方法切实可靠,提高精度的同时可有效提高工作效率。  相似文献   

2.
文章以青藏高原喀喇昆仑地区却哥隆玛冰川、锡亚琴冰川和巴尔托洛冰川3条规模较大且具代表性的冰川作为研究对象,利用Sentinel-1A卫星雷达影像和像素跟踪算法获取冰川表面流速数据,并基于数字高程模型(digital elevation model, DEM)和冰川表面流速数据,运用层流理论对目标冰川进行厚度反演和冰储量估算;采用全球冰川厚度产品对反演结果进行准确度评价,同时探讨采用层流理论反演冰厚的内在机制及存在的不确定性。结果表明,采用层流理论反演冰川厚度具有较好的可行性。研究结果可为青藏高原冰冻圈动态变化研究提供参考。  相似文献   

3.
无人机技术在测绘领域广泛应用,缩短野外测量时间的同时也给数据处理和数字化成图带来了繁重的工作。为了缩短数据处理时间,需要研究数据处理方法及流程,提高数据精度,从而使无人机测绘更广泛的应用于高海拔高山地区。本文利用无人机在海拔约3 800 m的高山地区测绘1∶2 000大比例尺地形图,通过Pix4Dmapper数据处理软件,生成高精度数字高程模型(DEM)以及绘制数字线划图(DLG)。结果显示:通过数据处理软件获取的地形图检查点平面位置中误差为0. 032 m,高程中误差为-0. 058 m,不仅简化了无人机数据处理流程,同时保证了数字地形图的数据质量,可为同类型低空摄影测量工作提供一定的应用模式和技术参考。  相似文献   

4.
海拔对人口分布具有重要影响,分析海拔与人口的相关性,可为区域生态保护、经济发展与人口政策制定提供依据。基于DEM数据与人口栅格数据,通过创建5 km×5 km渔网,利用空间自相关、Lorenz曲线、相关分析等方法研究乌江上游人口空间分布特征及其与海拔高程的关系,研究结果表明:1)贵州乌江上游地区人口分布呈“大分散,小集中”的分布特点,人口集中于北部、中部及南部;2)人口主要分布在1200~2000 m的中低山,中高山人口数量较少、人口密度较低;海拔1200~1600 m人口数量最多、人口密度最大;3)人口数量、人口密度与各级海拔面积随海拔上升变化大体一致,均随海拔的升高呈先增后减的倒“U”型变化特征。  相似文献   

5.
崂山古冰川遗迹的地质证据   总被引:1,自引:0,他引:1  
崂山是中国海岸线上的最高峰。研究发现,崂山发育有典型的古冰川侵蚀和堆积地貌,拥有我国东部罕见的冰碛海岸和冰碛扇等地貌类型。更新世期间,崂山至少发育过4次古冰川作用。更新世早期,崂山东部的雪线为60-90m(现代海拔),崂山及其周围共发育60余条古冰舌,东部的冰舌一直伸入黄海之中。孢粉组合特征说明,崂山在冰期具备形成冰川的气候条件;堆积物粒度曲线显示为冰川成因的沉积特征。研究还发现,中国东部的古冰川遗迹可能大部分被埋藏起来;区域地形特征和当地气候条件是决定雪线高度的关键因素。  相似文献   

6.
辽宁老秃顶子南坡植物生活型谱及其海拔变化   总被引:5,自引:0,他引:5  
基于研究区植物名录和野外样线调查统计数据,采用Raunkiaer生活型分类系统,对辽宁老秃顶子南坡植物生活型谱及其随海拔高度的变化特征进行分析研究.结果表明:(1)老秃顶子南坡植物生活型组成以地面芽植物为主,占40.8%;其次是高位芽植物和1年生植物,分别占21.8%和21.5%,隐芽植物也较多,占14.5%,地上芽植物很少,仅占1.4%.该生活型谱总体上反映了本区夏季温暖多雨、冬季寒冷且漫长的气候特点;(2)老秃顶子南坡植物群落的生活型谱随海拔高度的变化特征为:山麓~海拔1180m,随着海拔的升高,群落中中型高位芽植物比例明显增大,而地面芽植物比例明显减小;海拔1180m~山顶,随着海拔的升高,群落中中型高位芽植物比例明显减小,小型高位芽植物比例明显增大,至山顶高位芽植物基本消失,而地面芽植物比例则由9.1%显著增加到山顶的76.3%.  相似文献   

7.
为了实现公路震害地带性分布规律分析的自动化,研究公路震害空间分布特征,从概念、逻辑和物理3个层面设计了公路震害空间数据库,利用空间数据引擎技术,借助关系型数据库对数据进行存储与管理,建立了公路震害空间(EDH)数据库。基于此数据库,以映秀—汶川附近区域地质灾害与高程的空间分布关系为例进行了分析。分析结果表明:研究区域公路地质灾害的分布具有明显的高程差异性,高程低于1 500m区域的灾害分布很少;高程1 500~3 500m区域分布的地质灾害占总数量的85.4%;当高程上升到3 500m以后,随着高程的升高,地质灾害的数量反而减少。该数据库系统的建立,有效提高了公路震害空间分布特征分析的自动化程度和准确性。  相似文献   

8.
对以碳基金属气相沉积制备的MO2C膜表面粗糙度进行了测量;在测量基础上进行统计,找出了表面高度分布并确定表面粗糙度随时间和温度的变化规律。结果表明:MO2C膜表面粗糙化属快速粗糙化,粗糙度随时间的变化具有标度函数的特征;粗糙度随基底温度升高而增大。  相似文献   

9.
太行山中段植被分布特征及其多样性研究   总被引:1,自引:0,他引:1  
研究了太行山中段王屋山南坡的植被分布及其多样性特征,结果表明,该段山体分布最广的乔木树种是青冈(Cyclobalanopsis glauca)和千金榆(Carpinus cordata),樱桃忍冬(Sambucus willamsii)、珍珠梅(Sorbaria sorbifolia)、连翘(Forsythia suspensa)3种灌木在海拔1500~1600m处分布较多,分布最广的草本植物是羊胡子草(Carex rigescens)和唐松草(Thalictrum aquilegifolium).就物种多样性而言,海拔1600m左右的植物总物种数最多,为(18.67±1.53)种;乔灌木层的Shannon-Wiener多样性指数随海拔的升高大致呈“M”型变化,海拔1550m处乔灌木的多样性指数最小,仅为1.42±0.19,而草本多样性指数变化曲线呈单峰型,在海拔1500m左右达到最大值2.16±0.17.  相似文献   

10.
基于无人机摄影测量及随机振动测试的方法,探索在不封闭交通条件下进行桥梁状态评估的方法. 以长沙市某大桥为例,通过采用结构识别理论与无人机倾斜摄影技术分别对桥梁线型、桥梁病害、动力特性进行研究.利用无人机三维倾斜摄影技术重建目标桥梁三维实景模型并通过点云模型提取桥梁线型,将无人机测量线型与水准测量线型以及设计线型进行对比,研究发现线型差值的平均值为0.034?m,平均相对挠度值为L/12705(L为桥梁跨度),标准差为0.035?m,两者结果较为接近,验证了无人机测量桥梁线型的可靠性,也验证了运营桥梁期间外观尺寸无显著改变. 利用小型无人机技术对目标桥梁辅助进行外观质量调查,调查桥墩病害和支座损伤特征,结果表明桥梁无结构性损伤. 通过对结构进行环境振动测试,以行车、风等荷载作为激励,利用复模态指示函数(Complex Modal Indicator Function,CMIF)法捕捉结构模态参数(频率、振型、阻尼比),对比10?年前历史基线模态数据并综合考虑环境温度影响,判断该桥结构刚度无明显下降. 研究表明采用“无人机三维建模线型测量+无人机病害调查+随机振动测试”的桥梁健康状态的综合评估技术具有可行性、经济性及实用性.  相似文献   

11.
Due to climate changes, most of the alpine glaciers have retreated dramatically during the past decades. Thus it is significant to predict the alpine glacier variability in the future for a better understanding of the impact of climate changes on water resource. In this paper, we perform the numerical simulation on Urumqi Glacier No.1 in the eastern Tianshan, central Asia (hereafter Glacier No.1 for short) by considering both the mass balance and ice flow. Given the shape of the Glacier No.1, the velocity of the glacier is obtained by solving a two-dimensional nonlinear Stokes equation and simulated result is in agreement with the observation. In order to predict the variability of Glacier No.1 in the next decades, a climatic scenario is constructed with a temperature rise rate as 0.17°C/10 a and precipitation as constant during the period of 2005-2070. The simulation shows that, the glacier terminus will retreat slowly and the glacier will thin dramatically before 2040, while after year 2040, the glacier terminus retreat will accelerate. This study confirms the increasing retreat rate of alpine glaciers under global warming.  相似文献   

12.
Based on the field observations on Qiyi Glacier during the warm season of 2007, using a digital elevation model (DEM, 15 m resolution), we developed a distributed surface energy- and mass-balance model with an hourly resolution. The model described the effect of topography on shortwave solar radiation, and used a new parameterization for glacier albedo. The model was applied to Qiyi Glacier in the Qilian Mountain, China, for the period 20 : 00 30 June to 12 : 00 10 October 2007, to simulate the firn-line changes, the temporal and spatial variations of mass balance, and the glacial meltwater runoff. The results indicated that the patterns of altitudinal profile of glacier mass-balance were affected mainly by the altitudinal profile of albedo, and the status of the glacier mass balance was influenced directly by the values of albedo. The parameter sensitivity test showed that the model was sensitive to the air temperature lapse rate and precipitation gradient, and also sensitive to the threshold temperature for solid/liquid precipitation. Furthermore, the climate sensitivity test showed that the mass balance was more sensitive to air temperature than precipitation, and the response of mass balance to air temperature change was nonlinear while the response to precipitation change linearly. The negative mass balance trend of the glacier can not be reversed when precipitation increases by 20% and meanwhile air temperature rises by 1°C.  相似文献   

13.
The maritime glaciers are sensitive to climate change because of high annual precipitation and high air temperature in the region. A combined comprehensive study was carried out based on glacier mass balance observation, GPS-based glacier terminus position survey, glacier Ground Penetrating Radar, topography maps and RS satellite images in the Kangri Karpo Mountains, Southeast Tibet. The study revealed a strong ice mass loss and quick glacier retreat since the 1970s. Ata Glacier, one glacier from the south slope of the Kangri Karpo Mountains, has formed a 6-km-long terminal moraine zone at the end of the glacier since the 1970s, and the accelerating retreat is largely due to the strong glacier surface melting. Mass balance study on the other four glaciers on the northern side of the Kangri Karpo Mountains shows that they are in large negative mass balance and the glaciers had retreated 15--19 m from May 2006 to May 2007. The in-situ glacier observation also shows that the glacier retreat is more obvious in small glaciers. The enhanced ice mass deficit caused by climate warming and the ongoing extinction of many small glaciers in this region could seriously affect the water resources, environ- ments, local climate and regional sustainable development in the near future.  相似文献   

14.
Ice formation was studied on the Dasuopu Glacier located in the Mount Xixabangma (28°23′ N, 85°43'E) in the Himalayas. Snow pits and shallow ice cores are analyzed to reveal ice formation process. The results show that the ice formation process, or in other words, the process of densitifica-tion, on the col (7 000 m a.s. I.) of the Dasuopu Glacier is a stable, slow and gradual process. The snow-ice transformation on the glacier is estimated to be 30-40 m below the surface. The temperature on the Dasuopu Glacier is very low (~ - 14℃ at 10 m) and similar to that in polar type ice cap. We, therefore, speculate that the process of snow-ice transformation is undertaken under snow pressure, and that there is a percolation zone on the Dasuopu Glacier. The high altitude of the col and monsoon snow fall accompnied by heavy cloud and high albedo favorite the percolation zone formation.  相似文献   

15.
Ma  LingLong  Tian  LiD  Pu  JianChen  Wang  PengLing 《科学通报(英文版)》2010,55(20):2088-2096
This paper calculated and evaluated the area and ice volume changes of Kangwure Glacier in Mt. Xixiabangma, middle of Himalayas in the past 3 decades, based on the field survey of glacier boundary position by differential GPS and glacier depth by Ground Penetrating Radar (GPR), together with the topographic map and remote sense data. The studied data showed that the Kangwure Glacier has experienced significant mass deficit since the 1970s, with 34.2% of area loss, 48.2% of ice volume loss and 7.5 m of average thickness decrease. This result revealed that the ice volume loss of Himalayan glaciers was more serious than expected. Analysis of meteorological data from two weather stations in the region of Mt. Xixiabangma, shows that the air temperature of this region has risen from the middle of the 20th century to the beginning of the 21st century. Significant retreat of Himalayas glacier driven by climatic warming will have a remarkable impact on hydrology and ecosystem.  相似文献   

16.
为深入研究高寒流域河川径流的水源解析,选取雅鲁藏布江帕隆藏布上游流域为研究区,采用月流量、遥感积雪面积数据、实测冰川径流数据等多目标率定方法,改进单一依靠流量数据率定模型的方法,基于SPHY(Spatial Processes in Hydrology)水文模型开展水文模拟及径流组分研究,提高了总体建模质量.结果表明:在率定期和验证期Nash-Sutcliffe效率系数分别为0.95和0.94,模型具有较好的适用性.降雨径流、融雪径流、冰川径流和基流作为径流来源,占总径流的比例分别为10%、25%、45%和20%,冰川径流和融雪径流是最重要的补给来源.月尺度上,冰川径流在7-8月占比最大,融雪径流在4-6月占比最大,降雨径流在各月占比最小.冰川径流占比最高,短期内可提供更多水资源保障社会经济发展,长期而言冰川径流将逐渐减少,造成水资源短缺.因此,当地需提高应对径流变化潜在风险的策略.  相似文献   

17.
利用美国国家冰雪数据中心(NSIDC)最新发布的ICESat(云和地面高度卫星)R633版本的GLA12激光测高数据,使用重复轨最小二乘平面拟合的方法,计算得到东南极兰伯特冰川流域(Lambert)2003年~2009年的高程变化率.使用高度计重复观测数据确定表面高变化的时候,要考虑地形坡度的影响.假定在沿ICESat重复轨道小段范围内,可以用平面来拟合坡度和高程变化,并依此来计算高程变化.结果表明,Lambert冰川流域2003年~2009年平均高程变化率为(1±0.5)cm·yr-1.与已有研究成果以及交叉点获取的高程变化比较,提出的重复轨平面拟合方法有效可行.  相似文献   

18.
The glacier ELA is one of the important parameters reflecting climate change.Based on observations of the equilibrium line altitude(ELA) of Urumqi Glacier No.1 in the Tianshan Mountains,we established a statistical model between ELA and its major influencing factors,warm season air temperature(air temperature averages for May,June,July and August) and annual precipitation.Result showed that,warm season air temperature was the leading climatic factor influencing ELA variations.The glacier ELA ascends(descends) 61.7 m when warm season air temperature increases(decreases) by 1°C,and ascends(descends) 13.1 m when cold season precipitation decreases(increases) by 10%.In the period 1959-2008,the glacier ELA showed a general increasing trend,ascending108 m and reaching its highest altitude in 2008 at 4168 m a.s.l.,close to the glacier summit.If future climate is similar to that in the past 50 years,the ELA of Urumqi Glacier No.1 will still ascend with a speed of 2.16 m/a.However,If future climate is similar to that in the period 2000-2008,the ELA will still ascend with a speed of 6.5 m/a before it is stable.As a result of ELA variation,the accumulation area ratio(AAR) of the glacier showed a decreasing trend during the past 50 years.  相似文献   

19.
藏东南地区是研究海洋型冰川的天然宝库,帕隆藏布流域作为冰川活跃区,因其独特的地形地貌、气候条件,沿岸不仅堆积形态各异的第四纪冰碛垄、泥石流扇,而且发育断续分布的平台地形。利用无人机技术、高精度遥感影像、钻探、物探,结合实测剖面对藏东南典型第四纪堆积阶地成因进行详细的分析,为研究区域性堆积阶地成因提供依据,并得出以下结论:(1)雪瓦卡平台为第四纪堆积体,所在区域曾经发育了一个堰塞湖;(2)雪瓦卡平台第二级阶地下部为巨厚湖相砂层,上部为河床沉积卵砾石,这种下细上粗的物质接触关系可能为沉积区由堰塞湖转变为河道沉积,堰塞坝逐步疏通的过程;(3)上、下游支沟不仅为平台形成提供物质来源,而且为其形成提供地形地貌条件;(4)帕隆藏布沿岸断续分布的平台地形在形成过程中普遍受到上下游支沟冰川运动、泥石流发育的影响。  相似文献   

20.
Grove Mountain is an important nunatak region on East Antarctic Glacier that blocks the ice flow to- ward Lambert Glacier. The existence of nunataks and subglacial mountains leads to complex ice flow patterns, which are difficult to be measured by conventional ground-based methods. In this study, several JERS-1 and ERS-1/2 SAR images covering this area are used for 3-pass and 4-pass differential interferometric processing. The ice flow field of Grove Mountain and the eastern zone are derived and validated with related knowledge. The research shows that DINSAR is an effective method for meas- uring complex ice flow in Antarctic inland glacier. L-band DINSAR is more suitable for mid or fast ice flow than C-band over this region.  相似文献   

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