面向对象的极高海拔区水体及冰川信息提取——以珠穆朗玛峰国家级自然保护区核心区为例

极高海拔地区多为河流发源、冰川发育地,由于地形起伏强烈,且野外考察验证工作困难,传统的遥感信息提取方法很难保证该地区水体及冰川的提取精度。本文基于ASTER影像,运用面向对象的图像信息自动分析方法,对珠穆朗玛峰国家级自然保护区核心区的水体及冰川信息进行了提取研究。为保证信息提取的准确度,将数字高程模型(DEM)及其衍生数据(坡度、坡向),归一化植被指数(NDVI)数据,及有助于区分水体、冰川与其他地物的相关指数(冰雪指数NDSII)及波段运算结果(b1-b3)、(b3/b4)等,分别作为一个波段叠加到原始图像中,使之成为对目标地物光谱特征的有益补充。并对不同类型的水体及冰川进行多级、多尺度分割,以满足其对分割尺度的不同要求。分割完成后,综合考虑目标地物的光谱特征、纹理特征、空间结构特征,根据各特征指数的直方图信息,设定合适的阈值,建立了各水体及冰川类型信息提取的知识规则,并结合实地调查对信息提取的精度进行验证,改进了ASTER遥感影像自动快速提取极高海拔区水体及冰川信息的实用模型。     

青藏高原冰雪消融区岩漠动态变化遥感监测研究现状与展望

青藏高原作为地球第三极增温明显,相关研究多集中于青藏高原冰雪动态,很少关注冰雪消融后岩漠的变化。岩漠通过地气相互作用影响着全球气候变化的区域差异。本文通过梳理青藏高原冰雪、冰雪消融区、岩漠动态变化遥感监测方法体系,着重分析了各遥感数据来源及提取方法的优缺点和适用性,并对基于遥感技术条件下青藏高原冰雪动态监测、冰雪消融区岩漠动态变化监测的数据来源、研究方法与技术进行了总结。目前,青藏高原冰雪动态变化遥感监测数据来源多样、研究方法成熟,而冰雪消融区岩漠动态变化遥感监测尚未形成系统研究。在人为干扰不明显背景下,青藏高原冰雪消融区岩漠的动态变化,在一定程度上也可作为对冰雪变化遥感监测的补充。     

青藏高原冰川变化遥感监测研究综述

在全球变暖影响下,青藏高原冰川消融造成的冰川径流增大、冰湖溃决等问题威胁着山区及其周边居民的生命财产安全,对青藏高原冰川变化的研究日益紧迫。本文综述了国内外山地冰川变化遥感监测手段的发展、冰川面积及冰面高程变化的遥感监测研究现状、存在问题与发展趋势,并总结了中国青藏高原冰川变化遥感监测研究的主要成果。此外,本文基于2003-2009年ICESat/GLAS数据,计算了青藏高原各山区冰面高程变化及其冰川消融量。结果显示：青藏高原冰川面积持续减少,青藏高原冰面高程的平均变化为-0.24±0.03 m/a,冰川融水量为-14.86±11.88 km³/a,冰川变化呈现从青藏高原东、南外缘山区往内陆与西、北部山区减慢的时空特征。     

城镇扩张的多源遥感图像动态监测分析

遥感动态监测城镇扩展己成为一个重要的研究和应用领域。利用ASTER和TM多源多时相遥感影像和地形数据,以福建省漳州市区为示范区,对城镇建筑用地扩张进行了遥感监测。研究认为,对于ASTER影像,综合利用光谱知识、多时相植被指数、城镇建筑用地的地形分布等建立分类决策规则,可以有效提取城镇建筑用地信息(精度不低于90%);研究提出用较新时相影像获取的城镇建筑用地限定较早时相影像城镇建筑用地提取范围的思路,拓展了TM影像三指数法的应用范围,以此保证了较早时期TM影像城镇信息的有效提取。     

遥感影像提取数据的后处理技术研究

遥感信息的自动提取是当今空间信息领域的研究难点和重点,常见的提取方法能在一定程度上实现自动提取,但提取后的空间数据如道路、建筑物,存在着属性信息缺失、质量不高等问题,无法直接用于实际生产.为了解决这个问题,本文对遥感影像提取数据后处理过程进行研究,基于自动提取结果,借鉴制图综合领域中的算子和算法,并根据典型矢量要素的自身特征,制定规则库进行制图综合处理.同时引入OpenStreetMap数据进行多源数据融合,解决提取信息属性不足的问题,最终形成一套适合半自动生产加工的遥感影像数据提取后处理方法.与传统后处理方法相比,本文提出的方法可以大大提高系列比例尺地形图制作速度和自动化水平,提升基础地理信息数据快速生产更新效率.     

多源遥感影像融合处理提取格拉丹东雪山区域特征信息

2022年7月中国地质大学(武汉)冰川勘测组与登山组,在格拉丹东雪山开展了“第二次大学生长江源科考”工作。为详细分析该区域冰川时空特征信息,以此次科研数据为支撑,结合光学遥感影像解译、InSAR形变信息提取、激光雷达测高及高精度大地测量,进行了多源遥感影像融合处理研究。针对格拉丹东雪山及典型冰川,采用高分卫星GF1、GF6、GF7、ZY3与Landsat7遥感影像,利用空三加密、频域影像互相关匹配、波段比值法及目视解译,提取区域DOM、冰川面积及条数分布;利用Sentinel-1A、ICESat-2影像,以SAR影像空间域互相关偏移量追踪方法为支撑,分别提取冰川表面流速及高程变化;利用青海省域北斗CORS站点,采用Gamit/Globk双差无电离层组合模型、卫星星站差分(real-time extended,简称RTX)及RTK(real-time kinematic)方法,计算所有控制点三维空间坐标及高程异常值。结果表明：格拉丹东雪山共发育冰川512条,年均增长率为3.12%,面积1 111.96 km²,年均退缩速率为0.63%;姜根(古)迪如冰川日均最大流速...     

从卫星雷达提取地面高程信息的原理与应用

综述各种从卫星雷达影像提取地面高程信息的基本原理及其处理流程。首先分析雷达测量的特征及其与一般航测遥感的基本差别，随着着重介绍了从单幅雷达影像和各种干涉模式下的雷达影像提取地面高程信息的原理和数据处理流程。最后叙述了雷达干涉测量的应用领域，列出了INSAR在地形测量、火山地形测量和D－IN－SAR在地形沉降监测中的应用，并对我国目前雷达数据处理所面临的问题和挑战进行了探讨。     

遥感影像云及云影多特征协同检测方法

遥感影像中云及云影不同程度地影响着地物信息的有效获取。随着多源遥感数据的日益丰富,交叉应用多源、多时相遥感影像复原云及云影区的影像,以有效地获取地类演变过程是遥感大数据应用研究的重要内容。高精度的云及云影检测是遥感影像云及云影区修复的前提和保障。复杂多变的光谱特征以及难以有效表达的空间形态特征,使云及云影一直存在检测过程复杂、适用性差和精度不高的问题,难以形成稳定有效的检测方法。在对厚云、薄云、冰雪及其他地类多光谱特性分析的基础上,本文提出了一种云及云影的多特征协同检测方法。首先,对冰雪、云及其他地物类型可分性较好的红、短波红外、热红外波段,利用SAM方法匹配云光谱特征曲线,并进一步结合短波红外波段像元绝对值区分云与冰雪,以及热红外波段像元绝对值区分云及其他地物类型;其次,通过组合云影定向移动模型与近红外波段亮度阈值检测出云影像元。对具备这些光谱波段的Landsat-8进行实验,结果表明多光谱曲线、“诊断性”波段及空间关系多特征耦合能有效地检测出影像中的薄云、厚云及云影,整体精度优于95%。     

基于SAR干涉数据的东帕米尔高原冰川变化

冰川变化监测对生态灾害预防、区域水资源调控、气候变化研究等意义重大。利用冰川在雷达干涉影像上表现出失相干这一特性,选用1998年ERS 1/2与2018年 Sentinel-1A重轨单视复数SAR数据,通过相干系数取阈值的方法获取东帕米尔高原两个时期的冰川边界,以Landsat TM/OLI影像和全球陆地冰川空间监测计划发布的数据验证本文冰川边界提取的精度,从而分析冰川变化。结果表明：① 拟合研究区相干系数图上相干系数γ与对应像元个数的曲线关系,冰川区像元个数会在低相干区域积累形成一个小的波峰。曲线一阶导数变缓的点（冰川区向非冰川区过渡的转折点）即为所选阈值点,利用SAR相干系数取阈值法提取的冰川边界与光学遥感影像结合RGI6.0数据提取的验证冰川边界具有较好的一致性,SAR干涉相干系数提取冰川边界的方法是可行而有效的,ERS 1/2与Sentinel-1A提取的冰川总面积精度均在90%以上,而且SAR数据能够有效提取光学遥感影像难以识别的冰川表碛覆盖;② 1998年和2018年东帕米尔高原冰川总面积减少了318.59 km2,年平均变化速率为-15.93 km2/a,冰川退缩面积占冰川总面积的23%;③ 对大、中型规模冰川来说,表碛覆盖型冰川退缩较其他冰川明显;从坡向上来看,20年各个坡向冰川均有所退缩,其中东南坡冰川退缩最多,西坡冰川退缩最少;从海拔上来看,1998年冰川集中分布在4519~5421 m海拔区间内,2018年集中分布在4682~5320 m海拔区间内;在3325~5710 m海拔区间内冰川退缩明显,4915 m海拔附近达到退缩极大值。     

基于开源数据和条件生成对抗网络的地形重建方法

如何使用少量的地形特征复原地形地貌一直为地学领域的难题。本文使用开源数据集提取地形特征要素,使用地形特征要素作为约束条件构建了用于生成DEM的条件生成对抗网络(Conditional Generative Adversarial Networks, CGAN),设计了基于开源DEM、开源DEM与遥感影像组合、以及5m高精度DEM提取地形特征要素生成DEM的对比实验,并对结果进行视觉效果、相关性分析以及地形因子的对比与评价。结果表明:(1)在视觉效果上,3种不同方式生成的DEM在视觉效果上均十分逼近原始5 m DEM,都远好于传统插值方法生成DEM,基于开源12.5m DEM提取要素和1m遥感影像的重建效果最接近于原始5 m DEM;(2)在相关性上,三种不同方式生成的DEM与原始5m DEM相关性均能达到0.75以上,组合开源数据提取要素重建DEM与原始5 m DEM相关性可达到0.85以上;(3)在地形因子方面,基于开源12.5 m DEM和1 m遥感影像提取要素重建DEM的坡度和坡向的分布趋势与原始5 m DEM最为一致。本文为高精度DEM建模提供了新的思路,在高精度DEM难以获取...     

Recreational value of glacier tourism resources: A travel cost analysis for Yulong Snow Mountain

Glaciers, with their unique and spectacular appearances and rich and varied terrain, have received widespread attention and become important tourist attractions. This paper uses the travel cost method to estimate the recreational value of the glacier tourism resources of Yulong Snow Mountain (also called Jade Dragon Snow Mountain), which is the most developed glacier tourist attraction in China. First-hand information was obtained through field surveys, and the travel costs of visitors visiting the Yulong Snow Mountain glacier were calculated before the method was applied to evaluate the recreational value of the focal glacier resource. The results show that the Yulong Snow Mountain consumer surplus associated with its glacier resources in 2016 ranged from 645.59-3439.10 million CNY, and the total recreational value ranged from 1.97-8.17 billion CNY. Approaches allocating travel costs across multiple recreational sites, however, can vary, and there is large difference in estimated results depending on used approaches. Nevertheless, the results of the analysis can help understand the socio-economic value of glacier resources and provide a reference for their development and protection.     

Vegetation change as related to terrain factors at two glacier forefronts,Glacier National Park,Montana, U.S.A.

Glacier recession is a globally occurring trend. Although a rich body of work has documented glacial response to climate warming, few studies have assessed vegetation cover change in recently deglaciated areas, especially using geospatial technologies. Here, vegetation change at two glacier forefronts in Glacier National Park, Montana, U.S.A.was quantified through remote sensing analysis,fieldwork validation, and statistical modeling.Specifically, we assessed the spatial and temporal patterns of landcover change at the two glacier forefronts in Glacier National Park and determined the role of selected biophysical terrain factors(elevation, slope, aspect, solar radiation, flow accumulation, topographic wetness index, and surficial geology) on vegetation change(from nonvegetated to vegetated cover) at the deglaciated areas.Landsat imagery of the study locations in 1991, 2003,and 2015 were classified and validated using visual interpretation. Model results revealed geographic differences in biophysical correlates of vegetation change between the study areas, suggesting that terrain variation is a key factor affecting spatialtemporal patterns of vegetation change. At Jackson Glacier forefront, increases in vegetation over some portion or all of the study period were negatively associated with elevation, slope angle, and consolidated bedrock. At Grinnell Glacier forefront,increases in vegetation associated negatively with elevation and positively with solar radiation.Integrated geospatial and field approaches to the study of vegetation change in recently deglaciated terrain are recommended to understand and monitor processes and patterns of ongoing habitat change in rapidly changing mountain environments.     

桂北下震旦统杂砾岩成因之探讨

广西北部分布着下震旦统两套厚度大的杂砾岩系,即长安组与南沱组,均由含砾泥质岩、含砾砂岩及其夹一些砂。泥岩组成。过去认为与冰川作用有关,称之为“冰碛层”等等。近年来,人们对其成因有所争议。笔者借实习之机,在该区对南沱组杂砾岩系进行野外与室内研究,根据其岩性特征、砾石成分,砾石形态和表面特征,以及其夹层沉积特征和粒度分析结果,认为这套杂岩系不仅具有冰川作用的痕迹,而且还有正常海洋沉积性质,它是由大陆冰川携带碎屑入海消融后迅速堆积,受重力等因素形成的泥石流沉积物,属冰融泥石流沉积。     

机载LiDAR地形特征信息快速提取

为更有效地获取地形特征信息，提出一种机载LiDAR地形特征信息快速提取算法。首先，通过构建二次曲面拟合模型，建立实测LiDAR地形数据与拟合曲面的几何规则；然后，采用LM算法迭代参数寻优，获得最优化结果下的地形拟合参数，计算拟合时间及拟合精度；最后，以地形拟合模型为基础，进行地形特征信息的快速提取。通过机载LiDAR实测数据验证，当最优搜索半径为2 m时，地形曲面的拟合时间仅为0.02 s，RMSE仅为5.09 cm。该算法保证了地形特征信息提取效率和精度，能够有效满足机载LiDAR科学研究和工程应用的技术需求。     

Glacier changes since the early 1960s,eastern Pamir,China

Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region.In the last 50 years,these glaciers have shrunk and lost ice mass due to climate change.In order to understand recent glacier dynamics in the region,a new inventory was compiled from Landsat TM/ETM+ images acquired in2009,free of clouds and with minimal snow cover on the glacierized mountains.The first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial photographs.Total glacier area decreased by 10.8%±1.1%,mainly attributed to an increase in air temperature,although precipitation,glacier size and topographic features also combined to affect the general shrinkage of the glaciers.The 19.3–21.4 km~3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.     

结合质心Voronoi图优化的三维Douglas-Peucker地形简化算法

在多尺度TIN的自动构建过程中,为使各尺度数据保持地形的主要特征,需要选择合适的地形简化方法提取地形的结构特征信息。传统的3D Douglas-Peucker算法通过设定距离阈值参数对地形进行简化,简化后只保留了山脊线、山谷线等主要地形特征,而未考虑局部细节,难以顾及局部地形起伏变化明显的区域;而质心Voronoi图能够以地形因子作为密度函数,通过迭代驱动种子点向地形起伏较大的区域聚集,但其在主要地形特征的表达方面有缺失。为此,本文将二者的特点结合,在利用传统的3D Douglas-Peucker算法简化的同时,通过质心Voronoi图迭代加入局部起伏较大的特征点,综合考虑主要结构特征及局部起伏对地形进行简化,并在多个简化级别下对原始3D Douglas-Peucker算法和本文优化算法进行了对比。实验结果表明,相对于原始算法,本文优化算法在各简化级别下简化误差降低13.6%以上,具有更高的地形表达精度,且能够更好地逼近原始地形。     

Digital terrain modelling using Corona and ALOS PRISM data to investigate the distal part of Imja Glacier, Khumbu Himal, Nepal

This study used Corona KH-4A and Advanced Land Observing Satellite (ALOS) PRISM images to generate digital terrain models (DTMs) of the distal part of Imja Glacier,where a few supraglacial ponds (～0.07 km 2) expanded into the large Imja Glacier Lake (Imja Tsho,～0.91 km 2) between 1964 and 2006.DTMs and subsequently derived topographical maps with contour intervals of 1 m were created from the high-resolution images (Corona in 1964 and ALOS in 2006) in the Leica Photogrammetric Suite (LPS) platform.The DTMs and topographic maps provided excellent representation of the elevation and micro-topography of the glacier surface,such as its supra-glacial ponds/lake,surface depressions,and moraine ridges,with an error of about +/-4 m (maximum).The DTMs produced from the Corona and ALOS PRISM images are suitable for use in studies of the surface change of glaciers.The topographical maps produced from the Corona data (1964) showed that part of the dead ice in the down-glacier area was even higher than the top of the lateral moraine ridges,while the glacier surface in the up-glacier area was noticeably lower than the moraine crests.This suggests more extensive melting of glacier ice in the up-glacier area before 1964.The average lowering of the glacier surface from 1964 to 2006 was 16.9 m for the dead-ice area west of the lake and 47.4 m for the glacier surface east of the lake;between 1964 and 2002,the lake surface lowered by 82.3 m.These figures represent average lowering rates of 0.4,1.1,and 2.2 m/year for the respective areas.     

基于DEM的黄土高原地形纹理概念模型

黄土高原“千沟万壑”的地貌形态,在多尺度空间下表现出显著自相似性,具有“局部无规则,宏观有规律”的纹理特征。目前,黄土高原地形纹理的提取方法及应用已经得到初步发展,但依然缺乏在理论层面的框架体系。本文在已有学者研究成果的基础上,限定黄土高原为研究范围,明确提出黄土高原地形纹理的概念模型,即内涵、特征、分类及表达。将内涵进行扩展,除已有的宏观形态地形纹理外,提出黄土典型地貌单元（黄土塬、梁、峁等）特征组合形成的地形纹理,以及黄土坡面坡度特征形成的地形纹理;指出以数字高程模型为主的数据表达将更有利于地形纹理的量化,特别是基于DEM派生的坡面地形因子能够扩展地形纹理的特征空间,丰富地形纹理分析的数据源;明确地形纹理的基本特征,分别是区域差异性、成因复杂性和尺度依赖性;构建划分体系,以地形纹理的基元显著性、纹理成因以及可视化形态进行类别划分。本文以期构建面向黄土高原的地形纹理概念模型,推动纹理分析方法在黄土高原的应用和发展。     

Post-sedimentary Transformation of Lateral Moraines-the Tributary Tongue Basins of the Kvíárj(o)kull(Iceland)

The Kvíárj(o)kull.a southern outlet glacier of the Vatnaj(o)kull,is confined in the mountain foreland by lateral moraines measuring a height of up to 150 m.Each of the lateral moraines shows consjderable breaches with deviations of the main moraine ridges.The paper discusses the possible origins of these modifications of the lateral moraines as result of:1)ice overlappings during glacier advances and subsequent breaches of the lateraltongue triggered by the preglacial relief conditions and the prehistorical moraine landscape leading to affiux conditions,3)drainage of ice-marginal glacier lakes and 4.volcanic activities,such as lava flows and volcanic-induced j(o)kulhlaups. A historic-genetic model of the formation of the lateral moraines is presented considering the breaches in the lateral moraines as result from glacier bifurcations and therefore as former tributary tongue basins.Such breaches in the lateral moraines are also common landscape features at glaciers outside of Iceland and are from wider importance for the paleoreconstruction of former glacier stages.The knowledge of their development is essential for an adequate relative age classification of individual moraine ridges.In regard to the origin of the debris the resedimentation of prehistoric till deposits by younger glacier advances plays a role in the formation of the lateral moraines apart from englacial and supraglacial sediment transfer processes.     

Post-sedimentary Transformation of Lateral Moraines——the Tributary Tongue Basins of the Kvíárjokull（Iceland）

The Kvíárjokull,a southern outlet glacier of the Vatnajokull,is confined in the mountain foreland by lateral moraines measuring a height of up to 150 m. Each of the lateral moraines shows considerable breaches with deviations of the main moraine ridges. The paper discusses the possible origins of these modifications of the lateral moraines as result of： 1） ice overlappings during glacier advances and subsequent breaches of the lateral moraine,2） bifurcations of the Kvíárjokull glacier tongue triggered by the preglacial relief conditions and the prehistorical moraine landscape leading to afflux conditions,3） drainage of ice-marginal glacier lakes and 4. volcanic activities,such as lava flows and volcanic-induced jokulhlaups. A historic-genetic model of the formation of the lateral moraines is presented considering the breaches in the lateral moraines as result from glacier bifurcations and therefore as former tributary tongue basins. Such breaches in the lateral moraines are also common landscape features at glaciers outside of Iceland and are from wider importance for the paleoreconstruction of former glacier stages. The knowledge of their development is essential for an adequate relative age classification of individual moraine ridges. In regard to the origin of the debris supply areas of the large-sized Kvíárjokull moraines,the resedimentation of prehistoric till deposits by younger glacier advances plays a role in the formation of the lateral moraines apart from englacial and supraglacial sediment transfer processes.