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Geomorphological and sedimentological evidences of palaeo-outburst flood events from TanglangLa-Gya catchment of River Indus, Ladakh, India 印度拉达克印度河TanglangLa Gya流域古突发洪水事件的地貌和沉积学证据
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2022-01-10 DOI: 10.1080/02723646.2021.2022339
D. Nag, B. Phartiyal, Pankaj Kumar, P. Joshi, Randheer Singh
ABSTRACT Gya river, one of the main tributary of Indus, hosts several scattered palaeoflood deposits. The chronology, genesis and spatiotemporal relationships of these scattered deposits can throw light to the regional and global climatic fluctuations and their implications for the evolution of the valley. The valley structure of the Gya river consists of a broad middle reach alternating with narrow valleys and gorges in the upper and lower reaches which can be blocked by the slightest of sediment discharge damming the entire valley. The geomorphological, sedimentological and chronological study in this valley reveals multiple short-lived lake phases at 21–19.9 ka, 13 ka and 4.5 ka in the broader reach of the river during the transition periods when climate rapidly fluctuates between cold-dry and warm-wet. The damming in the valley is the result of the glacial lake outbursts in the head waters of the Gya catchment blocking the narrow lower reaches of the main channel by massive sediment. These lakes that are formed by valley damming contains ~108 m3 of water which subsequently breach out causing significant geomorphic changes on reach scale along the Gya river channel.
贾河是印度河的主要支流之一,分布着多处零散的古洪水沉积。这些零散矿床的年代、成因和时空关系可以揭示区域和全球气候波动及其对山谷演变的影响。贾河的河谷结构由宽阔的中游与狭窄的河谷交替组成,上下游的峡谷可以被整个河谷的最轻微的泥沙流量所阻挡。该山谷的地貌、沉积学和年代研究表明,在气候在冷干和暖湿之间快速波动的过渡时期,河流较宽河段的21–19.9 ka、13 ka和4.5 ka有多个短暂的湖相。山谷中的筑坝是由于Gya流域上游的冰川湖爆发,大量沉积物堵塞了狭窄的主河道下游。这些由山谷筑坝形成的湖泊含有约108m3的水,随后决口,导致Gya河河道河段规模的地貌发生重大变化。
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引用次数: 0
Change detection of Jamuna River and its impact on the local settlements Jamuna河的变化检测及其对当地居民点的影响
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2022-01-10 DOI: 10.1080/02723646.2022.2026075
Md Ariful Haque, Sharmin Shishir, Anannya Mazumder, M. Iqbal
ABSTRACT Spatio-temporal change detection analysis of Jamuna River using low and medium-resolution satellite data between the years of 1972 and 2013 are dynamic to assess river spatio-temporal changes and their impacts on the local settlements over the specific time. This study employs remote sensing and geographic information system (GIS) proficiencies to identify the river bank shifting, erosion, and depositional features along with the population displacement. The satellite image of LANDSAT multispectral (MSS), thematic mapper (TM), and operational land imager (OLI) and thermal infrared sensor (TIRS) were used in this study. Supervised and unsupervised classification techniques have been used to identify land cover types and detect the changes using ArcGIS Pro 2.3.2. Supervised classifications performed well by validating ≥90% overall accuracy. The result shows total erosion was 3356 ha from 1972 to 2013, while the deposition was 5342 ha. Erosion and deposition cause the bank line shifting, river widening, and settlement displacement. Hundreds of displaced people suffered from loss of land, livelihood, increased poverty, food insecurity, lack of sanitation, and drinking water facilities. Thus, this study will be earnest in assisting the environmental management and associated planning including necessary measures.
摘要利用1972年至2013年的中低分辨率卫星数据对贾穆纳河进行时空变化检测分析,以评估特定时间内河流的时空变化及其对当地居民点的影响。本研究利用遥感和地理信息系统(GIS)的熟练程度来识别河岸移动、侵蚀和沉积特征以及人口迁移。本研究使用了陆地卫星多光谱(MSS)、专题测绘仪(TM)、操作陆地成像仪(OLI)和热红外传感器(TIRS)的卫星图像。监督和非监督分类技术已用于识别土地覆盖类型,并使用ArcGIS Pro 2.3.2检测变化。监督分类通过验证≥90%的总体准确率表现良好。结果表明,从1972年到2013年,总侵蚀面积为3356公顷,而沉积面积为5342公顷。侵蚀和沉积导致河岸线偏移、河流拓宽和沉降位移。数百名流离失所者失去了土地、生计、贫困加剧、粮食不安全、缺乏卫生设施和饮用水设施。因此,本研究将认真协助环境管理和相关规划,包括必要的措施。
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引用次数: 1
Mountain process regime characterization using a topographic morphological structural framework 使用地形形态结构框架的山过程状态表征
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2022-01-03 DOI: 10.1080/02723646.2021.2020968
B. Young, M. Bishop
ABSTRACT Complex mountain geodynamics are difficult to decouple due to forcing factors, feedback mechanisms, and system couplings that arise from interacting atmospheric, surface, and tectonic processes. The operational-scale dependencies and process–form relationships that govern the spatio-temporal extent of process regimes, which in turn govern relief production, have yet to be adequately characterized and mapped. This research establishes a topographic morphological structural framework for representing and querying the spatial organizational structure of the topography that governs, and is governed by mountain geodynamics. The spatial scale-dependent structure of the topography is accounted for using land-surface parameters and land-surface partitioning into distinct terrain units that represent important aspects of the geomorphological system. The properties and spatial topology of terrain units provide constraints for modeling process–form relationships, which are represented as process–form indices and synthesized using logistic regression to empirically detect glacial and bedrock river incision process regimes at the basin-scale for 31 basins in the Central Karakoram at about 80% accuracy. The topographic morphological structural framework approach provides a mechanism for tractable representation of scale-dependent topographic structure for automated characterization of the land surface, providing insight into polygenetic geomorphological systems and systems coupling through defined process–form relationships.
摘要复杂的山地地球动力学由于大气、地表和构造过程相互作用产生的强迫因素、反馈机制和系统耦合而难以解耦。控制过程制度时空范围的操作规模依赖性和过程形式关系,反过来又控制救济生产,尚未得到充分的表征和映射。本研究建立了一个地形形态结构框架,用于表示和查询管辖并受山脉地球动力学控制的地形的空间组织结构。地形的空间尺度相关结构是利用地表参数和地表划分为代表地貌系统重要方面的不同地形单元来解释的。地形单元的特性和空间拓扑为建模过程-形态关系提供了约束,这些关系被表示为过程-形态指数,并使用逻辑回归进行综合,以在盆地尺度上以约80%的准确率实证检测喀喇昆仑中部31个盆地的冰川和基岩河流切割过程。地形形态-结构框架方法提供了一种机制,用于对尺度相关地形结构进行可处理的表示,以自动表征地表,通过定义的过程-形式关系深入了解多成因地貌系统和系统耦合。
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引用次数: 0
Retrieving dry snow stratigraphy using a versatile low-cost frequency modulated continuous wave (FMCW) K-band radar 使用多功能低成本调频连续波(FMCW)K波段雷达反演干雪地层
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-12-06 DOI: 10.1080/02723646.2021.2008104
Jacob Laliberté, A. Langlois, A. Royer, Jean-Benoît Madore, F. Gauthier
ABSTRACT Considering the increased popularity for backcountry mountain recreation activities, potentially problematic snowpack interfaces are currently of great interest given their impact on snow stability. The identification of interface vertical locations and spatial variability in the snowpack is essential for avalanche danger forecasting. The Gaspé Peninsula specific climate often leads to a complex snowpack development, where the need of improved monitoring is important. The goal of this research is to assess an automated method to detect contrasted snow interfaces using a 24 GHz Frequency Modulated Continuous Wave (FMCW) portable radar. Based on different in-situ configurations, we compared the radar amplitude signals with in-situ snow geophysical measurements, including SnowMicroPenetrometer (SMP). Radar measurements have been done following two different protocols: (1) mobile radar looking-up and down in order to understand the radar-snow wave interactions and optimize its parameters for spatial variability assessment of contrasted snow layers and (2) fixed radar looking-up to evaluate its potential in monitoring snow stratigraphy temporal variability. Results show good agreements with compared validation data with 80% of manually identified interfaces detection and a vertical positioning error of 3 cm. The presented FMCW radar appears to have a good potential for spatial and temporal variability assessment of snowpack stratigraphy.
摘要考虑到野外山地娱乐活动越来越受欢迎,考虑到积雪界面对雪的稳定性的影响,目前人们对其潜在的问题非常感兴趣。雪堆中界面垂直位置和空间变异性的识别对于雪崩危险预测至关重要。加斯佩半岛特有的气候往往会导致复杂的积雪发展,因此需要改进监测。本研究的目标是评估一种使用24 GHz调频连续波(FMCW)便携式雷达检测对比雪界面的自动化方法。基于不同的现场配置,我们将雷达振幅信号与包括SnowMicroPenetrometer(SMP)在内的现场雪地球物理测量结果进行了比较。雷达测量是按照两种不同的协议进行的:(1)移动雷达向上和向下观察,以了解雷达-雪波的相互作用,并优化其参数,用于对比雪层的空间变异性评估;(2)固定雷达向上观察,以评估其在监测雪地层时间变异性方面的潜力。结果与对比验证数据吻合良好,80%的人工识别界面检测和3cm的垂直定位误差。所提出的FMCW雷达似乎在积雪地层的空间和时间变异性评估方面具有良好的潜力。
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引用次数: 0
Impacts of an extreme flood on large wood recruitment and transport processes 极端洪水对大型木材吸收和运输过程的影响
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-11-29 DOI: 10.1080/02723646.2021.1980958
D. J. Martin, R. Pavlowsky, J. Bendix, T. Dogwiler, J. Hess
ABSTRACT This research investigates impacts of an extreme flood on recruitment and transport of large wood (LW) in sub-basins of the North Fork River, Missouri. Data collection took place two months after a >500 year flood to characterize LW conditions before natural recovery processes could obscure impacts. We used sites from previous LW studies in the region as reference to help identify flood impacts. Results showed 1) LW load volumes were no different than reference sites, but individual LW pieces comprised a greater percentage of the total load, 2) a high proportion of pieces at flood-impacted sites contained root wads, 3) transport capacity of the flood-impacted sites was high compared to reference sites, and 4) LW recruitment increased exponentially with flood magnitude. These results suggest that extreme floods have a significant impact on the composition of the LW load, and that geomorphic impacts of such floods may result in enhanced transport capacities. Based on these findings, we present two possible post-flood LW response/recovery scenarios; one in which elevated transport capacity serves to speed system recovery to the pre-flood LW regime, and one in which the enhanced LW piece composition results in a new post-flood LW regime with an enhanced load.
摘要本研究调查了极端洪水对密苏里州北福克河次流域大型木材(LW)的吸收和运输的影响。在自然恢复过程可能掩盖影响之前,数据收集是在500年以上洪水发生两个月后进行的,以表征LW条件。我们使用了该地区以前LW研究的场地作为参考,以帮助确定洪水影响。结果表明:1)LW负荷量与参考地点没有差异,但单个LW块在总负荷中所占比例更大,2)受洪水影响地点的块中含有根洼的比例很高,3)与参考地点相比,受洪水影响的地点的运输能力很高,4)LW补充量随洪水大小呈指数级增加。这些结果表明,极端洪水对LW负荷的组成有重大影响,这种洪水的地貌影响可能会提高运输能力。基于这些发现,我们提出了两种可能的洪水后LW响应/恢复情景;其中提高的运输能力用于加速系统恢复到洪水前LW状态,以及其中增强的LW部件组成导致具有增强负载的新的洪水后LW状态。
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引用次数: 2
West Coast vegetation shifts as a response to climate change over the past 130,000 years: geographic patterns and process from pollen data 西海岸植被变化作为对过去13万年气候变化的响应:花粉数据的地理模式和过程
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-10-26 DOI: 10.1080/02723646.2021.1990506
K. C. Glover, J. George, L. Heusser, G. MacDonald
ABSTRACT We compiled pollen sequences from lake and offshore cores at least 6,000 years old (6 ka) for the Mediterranean and Marine ecoregions of the US West Coast. Principal Component Analysis highlighted vegetation differences in core-tops, the Holocene Thermal Maximum (6 ka) and Last Glacial Maximum (LGM, 19 ka). Core-top and HTM ordination produced clusters that reflected geographic clusters in the Sierra Nevada, and the Pacific Northwest coast. Little change in these clusters between 6-0 ka suggested that vegetation communities in coastal and alpine settings persisted, despite warmer global temperatures. PCA outliers reflect distinct pollen assemblages that often were isolated sites or bordered the Great Basin. During the LGM, greater shrub and herb presence in the Marine ecoregion interior indicated enhanced aridity, while conifer presence in coastal and Southern California indicated moist conditions. Qualitatively, tree taxa from the Last Interglacial (~130–120 ka) showed how vegetation shifted over 6–10 kyr from alder, to oak, then redwood, a successional pattern that began again at the Late Glacial (~15 ka). In future West Coast pollen studies, sampling and chronologic control at centennial resolution will enable further study of more time periods and rates of vegetation change in response to climate.
我们收集了来自美国西海岸地中海和海洋生态区至少6000年(6 ka)的湖泊和近海岩心的花粉序列。主成分分析强调了地核顶部、全新世热极大期(6 ka)和末次冰极大期(19 ka)的植被差异。核心顶部和HTM排序产生的集群反映了内华达山脉和太平洋西北海岸的地理集群。这些群落在6-0 ka之间的微小变化表明,尽管全球气温升高,沿海和高山环境中的植被群落仍然存在。PCA异常值反映了不同的花粉组合,这些花粉组合通常是孤立的地点或与大盆地接壤的。在LGM期间,海洋生态区内部灌木和草本植物的增加表明干旱加剧,而沿海和南加州针叶树的增加表明潮湿条件。在质上,末次间冰期(~130 ~ 120 ka)的树木类群显示了植被在6 ~ 10年间从桤木到橡树,再到红木的转变,这种演替模式在晚冰期(~15 ka)再次开始。在未来的西海岸花粉研究中,采样和百年分辨率的年代学控制将使我们能够进一步研究更多的时间周期和植被对气候的响应速率。
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引用次数: 2
Geomorphological features of the Jurassic Granites in NE Nigeria (Southern Sahara) 尼日利亚东北部(南撒哈拉)侏罗纪花岗岩地貌特征
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-10-21 DOI: 10.1080/02723646.2021.1993770
A. Bashir, M. Gül, Ceren Küçükuysal, Göksu Uslular
ABSTRACT This study investigates the spectacular geomorphological features of Jurassic (Younger) Granites in NE Nigeria by using field observations and some structural (i.e. joints) analyses. The study area is in the Sahel region of the Subsaharan of Africa as a transition zone between the Sahara Desert and Equatorial region, where many studies have focused on the loess deposits, ergs, climate change, and Saharan Desert boundary changes. Morphological features of rocks in the study area have not been widely discussed in the literature. However, inselbergs, ruwares, and pillar structures are the major landforms in this vast plain with an arid environment. Boulders, blocks, mushrooms, and corestones, tafoni, shelter caves, flared slopes, polygonal cracks, and weathering pits are minor features. Weathering products consisting of white-colored, granular quartz-bearing grus and red clayey laterite surround the granite masses. Subsurface weathering has favored the formation of major geomorphological features; however, subsequent superficial weathering leading to hydration and stripping occurred mostly under the humid climatic conditions with seasonal variation of dry and humid climatic conditions. Local paleoenvironmental – paleoclimatic conditions would have prevented excess weathering and erosion in the study area.
摘要:本文通过野外观察和构造(如节理)分析,探讨了尼日利亚东北部侏罗纪(更年轻)花岗岩的壮观地貌特征。研究区域位于非洲撒哈拉以南的萨赫勒地区,是撒哈拉沙漠与赤道地区之间的过渡地带,在这里有很多关于黄土沉积、地质、气候变化、撒哈拉沙漠边界变化的研究。研究区岩石的形态特征尚未在文献中得到广泛讨论。然而,在这片辽阔的干旱平原上,主要的地貌是石堡、土石和柱状结构。巨石、石块、蘑菇和岩心、塔福尼、庇护洞穴、喇叭形斜坡、多边形裂缝和风化坑是次要特征。花岗岩块体周围风化产物为白色粒状含石英砾石和红色粘土红土。地下风化形成了主要的地貌特征;然而,随后导致水化剥落的表层风化主要发生在湿润气候条件下,且干湿气候条件有季节变化。当地的古环境-古气候条件可能阻止了研究区过度的风化和侵蚀。
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引用次数: 0
A review of recent studies on landslide hazard in Latin America 拉丁美洲滑坡灾害的最新研究综述
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-09-25 DOI: 10.1080/02723646.2021.1978372
Alejandro César Valdés Carrera, M. Mendoza, Teodoro Carlón Allende, J. L. Macías
ABSTRACT Over the last few decades, the impact of landslides has increased in Latin America. However, there is a deficiency in the region of diagnostic studies on landslide hazards. This review analyzes the state of the art of studies on landslide hazard occurred in Latin America. A search for articles published from 2000 to 2019 was carried out in Scopus, WoS, SciELO, REDIB, and Redalyc. The search yielded 1,365 publications, which were purged obtaining 283 articles, analyzed through a database organized in four categories: general information, study area, research objectives, and methodology. We identified an increase in the number of publications from the year 2011. Seventy-five percent of the 20 countries in the region published papers on landslides that had occurred in these countries, mainly research focus on susceptibility and characterization, and a reduced number, on hazardousness, inventories, trigger factors and conditioning factors. The results suggest the opportunity to incorporate novel methods, tools, techniques, and inputs into research of landslides in Latin America. This review constitutes an analytical and critical contribution to the study of landslide hazards in the region and indicates the studies that are urgent to enforce its integral management in the region and in other intertropical zones.
在过去的几十年里,山体滑坡对拉丁美洲的影响越来越大。然而,我国在滑坡灾害诊断研究方面还存在不足。本文对拉丁美洲滑坡灾害的研究现状进行了分析。在Scopus、WoS、SciELO、REDIB和Redalyc中检索2000年至2019年发表的文章。通过一般信息、研究领域、研究目标、研究方法等4个分类的数据库,对1365篇论文进行了分析。我们发现自2011年以来,出版物数量有所增加。该地区20个国家中,有75%的国家发表了关于本国发生的山体滑坡的论文,主要集中在易感性和特征方面,对危险性、库存、触发因素和条件因素的研究较少。研究结果表明,有机会将新的方法、工具、技术和投入纳入拉丁美洲的滑坡研究。这项审查对研究该区域的滑坡灾害作出了分析性和关键性的贡献,并指出迫切需要进行哪些研究,以便在该区域和其他热带地区加强对其进行综合管理。
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引用次数: 7
Tectonics, weathering, erosion and soils 构造、风化、侵蚀和土壤
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-09-22 DOI: 10.4324/9781003124405-2
Joseph Holden
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引用次数: 0
Water and ice 水和冰
IF 1.6 4区 地球科学 Q4 ENVIRONMENTAL SCIENCES Pub Date : 2021-09-22 DOI: 10.4324/9781003124405-5
Joseph Holden
{"title":"Water and ice","authors":"Joseph Holden","doi":"10.4324/9781003124405-5","DOIUrl":"https://doi.org/10.4324/9781003124405-5","url":null,"abstract":"","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2021-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43067485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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Physical Geography
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