Geografiska Annaler Series A-Physical Geography最新文献_第8页

Testing lichenometric techniques in the production of a new growth-rate (curve) for the Breiðamerkurjökull foreland, Iceland, and the analysis of potential climatic drivers of glacier recession 测试地衣测量技术在冰岛Breiðamerkurjökull前陆新的生长速率(曲线)生成中的应用，并分析冰川消退的潜在气候驱动因素

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2019-06-30 DOI: 10.1080/04353676.2019.1622919

D. Evans, S. Guðmundsson, Jonathan L. Vautrey, Kate Fearnyough, W. G. Southworth

{"title":"Testing lichenometric techniques in the production of a new growth-rate (curve) for the Breiðamerkurjökull foreland, Iceland, and the analysis of potential climatic drivers of glacier recession","authors":"D. Evans, S. Guðmundsson, Jonathan L. Vautrey, Kate Fearnyough, W. G. Southworth","doi":"10.1080/04353676.2019.1622919","DOIUrl":"https://doi.org/10.1080/04353676.2019.1622919","url":null,"abstract":"ABSTRACT Independent dating of closely-spaced moraines on the west Breiðamerkurjökull foreland is used to test the accuracy of the size frequency (SF) and largest lichen (5LL) lichenometric dating techniques. The 5LL technique derived the most accurate ages for three undated moraines within the dated sequence but growth rates and lag times produced by the two methods (5LL = 0.71 mm yr−1 and 11 years; SF = 0.64 mm yr−1 and 7 years) were not significantly different. We therefore reject previous conclusions that any one technique is demonstrably inferior to the other, at least for dating glacial landforms created over the last 130 years in SE Iceland. Comparisons of climate trends and recession rates indicate that air temperature anomalies, particularly those of the summer, are the strongest driver of glacier retreat. No clear relationship between NAO trends and glacier retreat were identified, although a positive and/or rising trend in NAO is associated with the slowing of ice retreat overall, and the marked readvances of the mid-1950s, mid-1970s and mid-1990s are all coincident with positive and/or rising NAO 5yr moving averages. Summer and annual temperature trends, not the NAO, clearly show that recent accelerated global warming is driving the marked recession of the period 1995–2015. Over the last 100 years temperature has been the major driver of glacier terminus oscillations at west Breiðamerkurjökull but it is clear that extreme decreases in winter precipitation (i.e. 1960–1973) have the potential to increase retreat rates significantly even during times of below average annual temperatures.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"152 1","pages":"225 - 248"},"PeriodicalIF":1.5,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85411529","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: 7

Impacts of land abandonment and climate variability on runoff generation and sediment transport in the Pisuerga headwaters (Cantabrian Mountains, Spain) 土地撂荒和气候变率对Pisuerga上游产流输沙的影响(坎塔布连山)

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2019-04-09 DOI: 10.1080/04353676.2019.1591042

A. Pisabarro, Ramón Pellitero, E. Serrano, J. López‐Moreno

{"title":"Impacts of land abandonment and climate variability on runoff generation and sediment transport in the Pisuerga headwaters (Cantabrian Mountains, Spain)","authors":"A. Pisabarro, Ramón Pellitero, E. Serrano, J. López‐Moreno","doi":"10.1080/04353676.2019.1591042","DOIUrl":"https://doi.org/10.1080/04353676.2019.1591042","url":null,"abstract":"ABSTRACT The Atlantic mountains of Spain are suffering a strong landscape change due to a widespread and intensive emigration to urban areas since the 1950s. This process, representative of global developments in an imminent future, is dominated by urban societies and leads to deep landscape changes in which crop fields and grasslands are abandoned and progressively covered by forest and shrubs. These dynamics have caused in turn a decrease in the runoff and a general slowdown of geomorphological processes. The impacts of land cover change have been simultaneous to an irregularity in precipitation and a significant increase of temperatures. With this background, this paper assesses in detail the impact of landscape change occurred over the last decades (twentieth and twenty-first centuries) on the water and sediment yield in the Pisuerga catchment headwaters (Cantabrian Mountains, N Spain). We analyzed the different components of Global Change in a catchment of 233 km2 extent, that has passed from 15 to 2 habitants/km2, from multiple data sources. Evolution of land cover was reconstructed from aerial photographs, remote sensing and other resources. The climatic parameters have been studied through meteorological stations, and the hydrological and sedimentological responses over time are based on available runoff data and sedimentological analysis. Our results show a significant decrease in water and sediment transport mainly driven by vegetation increase occurred in a non-linear way, more intense immediately after abandonment. This fact opens the opportunity to control more accurately water resources in Mediterranean catchments through land use management.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"19 1","pages":"211 - 224"},"PeriodicalIF":1.5,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87730504","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: 6

Constraining 135 years of mass balance with historic structure-from-motion photogrammetry on Storglaciären, Sweden 限制135年的质量平衡与历史结构的运动摄影测量在Storglaciären，瑞典

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2019-03-26 DOI: 10.1080/04353676.2019.1588543

E. S. Holmlund, P. Holmlund

{"title":"Constraining 135 years of mass balance with historic structure-from-motion photogrammetry on Storglaciären, Sweden","authors":"E. S. Holmlund, P. Holmlund","doi":"10.1080/04353676.2019.1588543","DOIUrl":"https://doi.org/10.1080/04353676.2019.1588543","url":null,"abstract":"ABSTRACT Geodetic volume estimates of Storglaciären in Sweden suggest a 28% loss in total ice mass between 1910 and 2015. Terrestrial photographs from 1910 of Tarfala valley, where Storglaciären is situated, allow for an accurate reconstruction of the glacier's surface using Structure-from-Motion photogrammetry, which we used for past volume and mass estimations. The glacier's yearly mass balance gradient and net mass balance was also estimated back to 1880 using weather data from Karesuando, 170 km north-east of Storglaciären, through neural network regression. These combined reconstructions provide a continuous mass change series between the end of the Little Ice Age and 1946, when field data become available. The resultant reconstruction suggests a state close to equilibrium between 1880 and the 1910s, followed by drastic melt until the 1970s, constituting 76% of the 1910–2015 ice loss. More favourable conditions subsequently stabilized the mass balance until the late 1990s, after which Storglaciären started losing mass again. The 1910 reconstruction allows for a more accurate mass change series than previous estimates, and the methodology can be used on other glaciers where early photographic material exists.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"1 1","pages":"195 - 210"},"PeriodicalIF":1.5,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89748329","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: 9

Estimating daily average net radiation in Northern Mongolia 北蒙古日平均净辐射估算

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2019-02-27 DOI: 10.1080/04353676.2019.1583498

Munkhdavaa Munkhjargal, L. Menzel

{"title":"Estimating daily average net radiation in Northern Mongolia","authors":"Munkhdavaa Munkhjargal, L. Menzel","doi":"10.1080/04353676.2019.1583498","DOIUrl":"https://doi.org/10.1080/04353676.2019.1583498","url":null,"abstract":"ABSTRACT Net radiation is a key component of surface radiation balance and has a strong influence on hydrological processes via evapotranspiration. In this study, daily average net radiation (Rnmean) for all-sky conditions was investigated as a function of the estimated daily average global radiation (GRmean) during the summers of 2011 and 2012 (128 days total) in the Sugnugur Valley of Northern Mongolia. We present a simple alternative remote sensing approach that considers factors such as topography, cloud fraction, cloud optical thickness and surface albedo. First, a geometric model for the simulation of daily average global radiation (GRCS:mean) for clear-sky conditions was applied on a daily basis. It considers topographical effects, such as slope, azimuth and elevation. GRmean was then derived for all-sky conditions by coupling the averaged atmospheric products of MODIS. Finally, Rnmean was obtained as a function of the simulated GRmean using the linear regression parameters found at a permanent observation site. The results were validated with the data from a nearby temporary observation site. The root mean square errors (RMSE) were 44 and 52 Wm−2 for GRmean and 18 and 25 Wm−2 for Rnmean at the two different sites. This methodology requires few observations and offers a simple means for estimating GRmean with high spatial (30 m) and temporal (daily) resolution under any sky conditions in the absence of ground measurements. Furthermore, Rnmean can be modeled from the simulated GRmean at regional or watershed scales where ground observations exist at one site at least.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"17 1","pages":"177 - 194"},"PeriodicalIF":1.5,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76130749","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: 3

Elevated floodplains and net channel incision as a result of the construction and removal of water mills 由于水磨机的建造和拆除，河漫滩和河道网被抬高

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2019-02-10 DOI: 10.1080/04353676.2019.1574209

A. Maaß, H. Schüttrumpf

引用次数: 15

Temporal changes in wind conditions at Svalbard for the years 1986–2015 1986-2015年斯瓦尔巴群岛风况的时间变化

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2019-02-10 DOI: 10.1080/04353676.2019.1572973

Natalia Pilguj, Leszek Kolendowicz, M. Kryza, K. Migała, B. Czernecki

{"title":"Temporal changes in wind conditions at Svalbard for the years 1986–2015","authors":"Natalia Pilguj, Leszek Kolendowicz, M. Kryza, K. Migała, B. Czernecki","doi":"10.1080/04353676.2019.1572973","DOIUrl":"https://doi.org/10.1080/04353676.2019.1572973","url":null,"abstract":"ABSTRACT This paper presents trends in wind speed and wind direction indices at selected stations in Svalbard (Bjørnøya, Hopen and Ny-Ålesund) and in the NCEP/NCAR and ERA-Interim reanalysis for the period 1986–2015. The analysed wind indices include the sum of days (annual or seasonal) with the daily range wind speed or wind direction. Using the Mann-Kendall trend test, we look for temporal trends in these indices, compare the results for the measured and gridded datasets, and then analyse the spatial variability in those trends. For the stations, statistically significant decreasing trends are detected for the frequency of days with very low wind speed (≤2 m s−1) and for days with strong wind (>10 m s−1). From the reanalysis data, indices with wind speed of up to 5 m s−1 were characterized by decreasing trends, while indices with wind speed above the mentioned threshold show increasing trends. Wind direction indices are characterized by different tendencies in the Ny-Ålesund station, where local elements modify the dominant directions of the air mass advection. The trends vary in space for the given region. Reanalysis data show the biggest positive trend for the occurrence of northerly winds over the Greenland Sea and Arctic Ocean, which cannot be confirmed by measurements (no stations available). The trends in wind speed and direction indices may partly be explained by changes in the frequency of circulation patterns.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"4 1","pages":"136 - 156"},"PeriodicalIF":1.5,"publicationDate":"2019-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80863889","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: 7

Knickpoint evolution in a supraglacial stream 冰川上河流的断裂点演化

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2018-11-29 DOI: 10.1080/04353676.2018.1549945

Jayne E. Kamintzis, T. Irvine‐Fynn, Tom O. Holt, John P. P. Jones, Stephen Tooth, Hywel Griffiths, Bryn Hubbard

{"title":"Knickpoint evolution in a supraglacial stream","authors":"Jayne E. Kamintzis, T. Irvine‐Fynn, Tom O. Holt, John P. P. Jones, Stephen Tooth, Hywel Griffiths, Bryn Hubbard","doi":"10.1080/04353676.2018.1549945","DOIUrl":"https://doi.org/10.1080/04353676.2018.1549945","url":null,"abstract":"ABSTRACT Despite numerous studies of knickpoints in bedrock and alluvial channels, no detailed description of knickpoint change on ice has been reported to date. This paper presents the first investigation of knickpoint evolution within a supraglacial stream. Repeat longitudinal profile surveys of a knickpoint on Vadrec del Forno, Switzerland reveal a step height increase of 115 mm and upstream migration of 0.26 m over three days during the 2017 ablation season. Rates and magnitudes of erosion vary spatially across the knickpoint in relation to differing discharge regimes. At high discharges (∼0.013 m3 s−1), erosion is focused at the step base; at low discharges (∼0.003 m3 s−1), erosion is focused on the reach upstream of the knickpoint, at the step lip and the step-riser face. This results in replacement of knickpoint morphology, driven by frictional thermal erosion and hydraulic action. Pool formation further influences step morphology, inducing secondary circulation and increased melt at the base of the step-riser, causing steepening. Results highlight the complexities of water flow over knickpoints, demonstrating that the stream power law does not accurately characterise changing knickpoint morphology or predict retreat rates. Although morphological similarities have been reported between supraglacial and bedrock/alluvial channels, knickpoints in non-ice-walled channels will not necessarily respond to discharge similarly to those on ice due to the different erosional processes involved.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"32 1","pages":"118 - 135"},"PeriodicalIF":1.5,"publicationDate":"2018-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80766842","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: 1

Plucking enhanced beneath ice sheet margins: evidence from the Grampian Mountains, Scotland 冰盖边缘下的拔毛增强:来自苏格兰格兰扁山脉的证据

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2018-11-22 DOI: 10.1080/04353676.2018.1539829

D. Sugden, A. Hall, W. Phillips, M. Stewart

{"title":"Plucking enhanced beneath ice sheet margins: evidence from the Grampian Mountains, Scotland","authors":"D. Sugden, A. Hall, W. Phillips, M. Stewart","doi":"10.1080/04353676.2018.1539829","DOIUrl":"https://doi.org/10.1080/04353676.2018.1539829","url":null,"abstract":"ABSTRACT Concentrations of boulders are a common feature of landscapes modified by former mid-latitude ice sheets. In many cases, the origin of the boulders can be traced in the up-ice direction to a cliff only tens to hundreds of metres distant. The implication is that a pulse of plucking and short boulder transport occurred beneath thin ice at the end of the last glacial cycle. Here we use a case study in granite bedrock in the Dee Valley, Scotland, to constrain theory and explore the factors involved in such a late phase of plucking. Plucking is influenced by ice velocity, hydrology, effective ice pressure, the extent of subglacial cavities and bedrock characteristics. The balance between these factors favours block removal beneath thin ice near a glacier margin. At Ripe Hill in the Dee Valley, a mean exposure age of 14.2 ka on blocks supports the view that the boulder train formed at the end of ice sheet glaciation. The late pulse of plucking was further enhanced by ice flowing obliquely across vertical joints and by fluctuations in sub-marginal meltwater conditions. An implication of the study is that there is the potential for a wave of ice-marginal plucking to sweep across a landscape as an ice sheet retreats.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"100 1","pages":"34 - 44"},"PeriodicalIF":1.5,"publicationDate":"2018-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79342520","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: 5

Factors affecting bluff development around a mountain reservoir: a case study in the Polish Carpathians 影响山地水库周围断崖发育的因素:波兰喀尔巴阡山脉的案例研究

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2018-11-22 DOI: 10.1080/04353676.2018.1542202

Małgorzata Kijowska-Strugała, Ł. Wiejaczka, Jarosław Cebulski, Krzysztof Kiszka, M. Maślanka, Daria Maria Kramkowska

{"title":"Factors affecting bluff development around a mountain reservoir: a case study in the Polish Carpathians","authors":"Małgorzata Kijowska-Strugała, Ł. Wiejaczka, Jarosław Cebulski, Krzysztof Kiszka, M. Maślanka, Daria Maria Kramkowska","doi":"10.1080/04353676.2018.1542202","DOIUrl":"https://doi.org/10.1080/04353676.2018.1542202","url":null,"abstract":"ABSTRACT Evolution of the bluffs within the shore zone of a reservoir is dependent on many environmental factors. In this study, a characterization of bluffs was presented with reference to the entire shore zone of a mountain reservoir. The research was conducted on the Czorsztyn reservoir – one of the largest functioning reservoirs within the Polish Carpathians (created in 1997). The analysis was based on a study conducted in 2015 and 2016 with the use of a Terrestrial Scanning Laser (TLS) and Airborne Laser Scanning (ALS), (data from 2013). The objectives are to identify the bluffs’ height on the mountain reservoir shoreline and assess the impact of various environmental factors (geological basement, slope exposure and gradient, bluff position in a different part of the reservoir, water level, wave height and the presence of landslides) on bluff development. Environmental factors were assessed using statistical methods, Beta factor and Principal Component Analysis. After 18 years of operation, bluffs on the reservoir covered 89% of the shoreline. The maximum height reaches about 10.00 m, and most often does not exceed 2.00 m. The most developed bluffs (height) are found in the south-western and western exposures of the shoreline. Amongst the analyzed factors affecting the bluff development on the Czorsztyn reservoir, the wave height, water level, the position of bluffs within the shoreline, slope gradient and exposure were identified as the dominant factors based on statistical analysis. Due to the fact that multiple factors are acting together, the distinction of the dominant factor affecting bluff development is difficult.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"52 1","pages":"79 - 93"},"PeriodicalIF":1.5,"publicationDate":"2018-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83608504","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: 6

Characterization of the englacial and subglacial drainage system in a high Arctic cold glacier by speleological mapping and ground-penetrating radar 用洞穴测绘和探地雷达表征北极高寒冰川的冰川和冰下排水系统

IF 1.5 4区地球科学

Geografiska Annaler Series A-Physical Geography Pub Date : 2018-11-19 DOI: 10.1080/04353676.2018.1545120

M. Temminghoff, M. Temminghoff, D. Benn, D. Benn, Jason Gulley, Heïdi Sevestre

引用次数: 14