Developing frameworks for studies on sedimentary fluxes and budgets in changing cold environments

Geomorphic processes that are responsible for the transfer of sediments and landform change are highly dependent on climate and vegetation cover. It is anticipated that climate change will have a major impact on the behaviour of Earth surface systems and that the most profound changes will occur in high-latitude and high-altitude cold environments. Collection, comparison and evaluation of data from a range of different high-latitude and high-altitude cold environments are required to permit greater understanding of sedimentary fluxes in cold environments. The focus of the I.A.G./A.I.G. SEDIBUD (Sediment Budgets in Cold Environments) Programme is the analysis of source-to-sink fluxes and sediment budgets in changing cold environments. Establishing contemporary sediment fluxes in a diversity of cold environments will form a baseline for modelling. At a minimum, baseline information from defined SEDIBUD test sites must consist of measures of mean annual precipitation, stream discharge, suspended load, conductivity/TDS and dominant catchment processes. Reports from ongoing studies on sedimentary fluxes and budgets in three selected study sites in Arctic Canada, sub-Arctic Iceland and sub-Arctic Norway are presented and discussed in the context of effects of climate change on process rates and sediment budgets in sensitive cold environments. Comparable datasets and coordinated data collection and data exchange will be of use for the individual studies at the different study sites. In addition, comparable data sets and data exchange will help to improve our understanding of existing relationships between contemporary climate and sedimentary fluxes and will enable larger-scale integrated investigations on effects of climate change in changing cold environments

Warming-driven erosion and sediment transport in cold regions

We synthesized a global inventory of cryosphere degradation-driven increases in erosion and sediment yield, e.g., suspended load, bedload, particulate organic carbon, and riverbank/slope erosion. This inventory includes 76 locations from the high Arctic, European mountains, High Mountain Asia and Andes, and 18 Arctic permafrost-coastal sites, and they were collected from ~80 studies

Denudation and geomorphic change in the Anthropocene; a global overview

The effects of human activity on geomorphic processes, particularly those related to denudation/sedimentation, are investigated by reviewing case studies and global assessments covering the past few centuries. Evidence we have assembled from different parts of the world, as well as from the literature, show that certain geomorphic processes are experiencing an acceleration, especially since the mid-twentieth century. This suggests that a global geomorphic change is taking place, largely caused by anthropogenic landscape changes. Direct human-driven denudation (through activities involving excavation, transport, and accumulation of geological materials) has increased by a factor of 30 between 1950 and 2015, representing a ten-fold increase of per capita effect. Direct plus indirectly human-induced denudation (triggered by land surface alteration) is presently at least one order of magnitude greater than denudation due to purely natural processes. The activity of slope movements, which represent an important contribution to denudation, sediment generation and landscape evolution, also shows a clear intensification. Frequency of hazardous events and disasters related to slope movements (an indirect measure of process frequency) in specific regions, as well as at continental and global levels, has grown considerably, in particular after the mid-twentieth century. Intense rainstorm events are often related to slope movement occurrence, but the general increasing trend observed is not satisfactorily explained by climate. Sedimentation has augmented considerably in most regions and all kinds of sedimentation environments. Although the link between denudation and sedimentation is not direct and unequivocal, it is safe to assume that if sedimentation rates increase in different regions during a given period, denudation must have increased too, even though their magnitudes could be different. This augmentation, particularly marked from the second half of the last century onwards, appears to be determined mainly by land surface changes, in conjunction with climate change. The changes observed suggest: a) there is evidence at a global scale of a growing response of geomorphic systems to socio-economic drivers, being Gross Domestic Product density, a good indicator of the human potential to cause such impacts; b) Land use/cover changes enhance effects of climate change on global denudation/sedimentation and landslide/flood frequency, and appear to be a stronger controlling factor; c) Our findings point to the existence of a global geomorphic change. This manifestation of global change is especially evident since the ?great geomorphic acceleration? that began in the middle of the 20th century, and constitutes one of the characteristics of the proposed Anthropocene.This work was supported, at different stages, by projects: FEDER, AEI, CGL2017-82703-R (Ministerio de Ciencia e Investigacion, Spain) and PICT2011-1685; MTM2014-56235-C2-2215 (Ministerio de Ciencia, Tecnología e Innovacion, Argentina). We also thank Dr. Anthony R. Berger for critical review and writing assistance

Untersuchungen über das Morphoklima in einem subarktisch-ozeanisch geprägten Periglazialgebiet in Ost-Island {Austfiröir, Austdalur)

Im Rahmen prozeßgeomorphologischer Untersuchungen erfolgt die Kennzeichnung des gegenwärtigen Klimas bis heute noch häufig ausschließlich über monatliche und jährliche Mittel- bzw. Summenwerte der Windgeschwindigkeit, der Temperatur und des Niederschlages. Da die meisten geomorphologischen Prozesse jedoch aus diskreten Prozeßereignissen bestehen, die nur wenig bzw. keinen Bezug zu derartigen meteorologischen Mittel- und Summenwerten aufweisen, ist eine aus geomorphologischer Sicht sinnvollere statistisch-quantitative Auswertung von meteorologischem Rohdatenmaterial erforderlich. In der vorliegenden Untersuchung wird am Beispiel des subarktisch-ozeanisch geprägten periglazialen Berglandes der Isländischen Austfiröir das gegenwärtige "Morphoklima" (AHNERT 1982, 1987, 1996) analysiert, wobei die Betrachtung der Häufigkeiten bzw. Wiederkehrzeiten von meteorologischen Ereignissen bestimmter Größe und der Häufigkeiten geomorphologisch relevanter Schwellenwerte im Mittelpunkt des Interesses steht. Es werden Eigenschaften des aktuellen Wind-, Temperatur- und Niederschlagsregimes aufgezeigt, welche die Art, Häufigkeit, Dauer und Intensität bzw. die absolute und relative Bedeutung der im rezenten periglazialen Prozeßgefüge auftretenden Formungsprozesse inwesentlichem Maße steuern.In process-geomorphological investigations, until today, the present-day cl imate is often only characterized by monthly and annual means or sum values of wind speed, temperature, and precipitation. Because most geomorphological processes consist of discrete process events which are only little or not correlated to these meteorological means or sum values there is a need for a more useful statistical analysis of meteorological data. In this investigation the "morphoclimate" (AHNERT 1982, 1987, 1996) of the periglacial mountains of the lcelandic Austfiröir is analyzed with special interest (1) in the frequencies or recurrence intervals of meteorological events of given magnitudes, and (2) in the frequencies of geomorphologically important thresholds. Characteristics of the current wind-, temperature-, and precipitation regime which control the type, frequency, duration, and intensity or the absolute and the relative importance of the geomorphological processes operating in the recent periglacial process structure are presented

Timescales of sediment dynamics, climate and topographic change in mountain landscapes (SedyMONT) - Erdalen and Bødalen site project, 2012.

The focus of this Norwegian Individual Project "Timescales of sediment dynamics, climate and topographic change in mountain landscapes (SedyMONT) - Erdalen and Bødalen site project, 2012" within SedyMONT, is on the Erdalen and Bødalen catchments in Nordfjord, western Norway. Both valleys provide based on the ongoing reserach, excellent opportunities to integrate existing and detailed quantitative knowledge on Holocene process rates with new data on sub-recent and contemporary solute and sediment fluxes and process rates generated within this project. Contemporary sediment flux data was established by the continuation of the existing monitoring programme in Erdalen and by the new instrumentation of the Bødalen catchment. This new monitoring programme, in combination with repeated analyses of surface water chemistry, atmospheric solute inputs and granulometric analyses of suspended sediments provided high-resolution data to analyse and quantify present-day sediment and solute fluxes as well as sediment sources, denudation rates and meteorological and topographic /landscape morphometric controls of denudative processes. In addition to standard methods for monitoring bedload transport, innovative techniques like shock sensors and biofilm analysis were applied to analyse channel stability/mobility and bedload transport rates in both valleys. Samples of filtered surface water and suspended particulate material collected on filters was compiled to estimate the particulate and dissolved loads of runoff from the Erdalsbreen glacier in Erdalen and the Bødalsbreen glacier in Bødalen. The volume and composition of lake sediments were studied using echosounder, georadar and coring. Investigations on volumes and architecture of storage elements (valley infills, talus cones) using different geophysical methods like georadar and seismic refraction surveys were performed to further improve the quantitative knowledge on Holocene process rates. Detailed mapping was performed and interpreted in combination with digital elevation models and data