scholarly journals The impact of pro‐glacial lakes on downstream sediment delivery in Norway

2014 ◽  
Vol 40 (7) ◽  
pp. 942-952 ◽  
Author(s):  
Jim Bogen ◽  
Mengzhen Xu ◽  
Patricia Kennie
Keyword(s):  
Glacial Lakes ◽  
Sediment Delivery ◽  
The Impact

scholarly journals Geospatial Analysis and Simulation of Glacial Lake Outburst Flood Hazard in Hunza and Shyok Basins of Upper Indus Basin

2020 ◽  
Author(s):  
Syed Naseem Abbas Gilany ◽  
Javed Iqbal ◽  
Ejaz Hussain
Keyword(s):  
Flood Hazard ◽  
Indus Basin ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Digital Repository ◽  
Adaptation Measures ◽  
High Discharge ◽  
Upper Indus Basin ◽  
Study Results ◽  
The Impact

Abstract. The UIB (Upper Indus Basin) is prone to GLOFs (Glacial Lake Outburst Floods). Physical monitoring of such a large area on regular basis is a challenging task especially when the temporal and spatial extent of the hazard is highly variable. The purpose of this study was to map the potentially dangerous glacial lakes and simulate the associated hazard in the downward settlements using HEC-RAS in the GIS environment using Landsat 7 remote sensing data. The study was conducted in Hunza and Shyok sub-basins of UIB where there are several human settlements which are endangered due to the GLOF hazard. Sudden breaches in the unstable moraine dams adjoining receding glaciers may occur because of rapid and huge accumulation of turbulent water in the glacial lakes. The ASTER DEM (Digital Elevation Model) is utilized to detect flow accumulation of glacial hazard involving slope, elevation, and orientation of the mountain glaciers. The study results revealed that settlements of Hunza and Shyok basins are threatened by the GLOFs hazard. Keeping in view the seasonal growth of the potentially dangerous glacial lakes of Hunza basin, a low discharge of 3500 m3/s from potentially dangerous glacial lake can affect 40 %, whereas, a moderate discharge of 5000 m3/s can affect 60% and a high discharge of 7000 m3/s can affect 80 % of the Shimshal village habitat. In Shyok basin, a low discharge of 100 m3/s from both lakes can affect 20 %, whereas, a moderate discharge of 300 m3/s can affect 30 % and a high discharge of 500 m3/s can affect 40 % of the Barah village habitat. The results of the study can provide a platform for the establishment of an early warning and monitoring system to minimize the impact of future GLOFs. Accurate and comprehensive knowledge of potentially dangerous GLOFs is of utmost importance for risk management. A digital repository of GLOFs can enhance the ability to inform policy makers on the vulnerability, risk mitigation and action/adaptation measures.

scholarly journals Sediment Budgets for Small Salinized Agricultural Catchments in Southwest Australia and Implications for Phosphorus Transport

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3564
Author(s):  
Robert J. Wasson ◽  
David M. Weaver
Keyword(s):  
Gully Erosion ◽  
Delivery Ratio ◽  
Phosphorus Transport ◽  
Rill Erosion ◽  
Sediment Delivery ◽  
Sediment Storage ◽  
Agricultural Catchments ◽  
Sediment Budgets ◽  
Southwest Australia ◽  
The Impact

Examples of sediment budgets are needed to document the range of budget types and their controls. Sediment budgets for three small agricultural catchments (7.6 to 15.6 km2) in southwestern Australia are dominated by channel and gully erosion, with sheet and rill erosion playing a subordinate role. Erosion was increased by clearing naturally swampy valley floors and hillslopes for agriculture and grazing, and episodic intense rainstorms. The proportion of sediment from channel and gully erosion in the sediment budget appears to be determined by the depth of alluvial fills. Dryland salinization caused by clearing native vegetation has connected hillslopes to channels across narrow floodplains, increasing the Sediment Delivery Ratio (SDR). Yield and SDR are found to be insensitive to major in-catchment changes of vegetation cover after initial clearing, the ratio of sheet and rill erosion/channel and gully erosion, and sediment storage masses. This supports the idea that yield alone is often a poor indicator of the impact of land use and land management change. Riparian vegetation would reduce sediment yield but not phosphorus yield. This study demonstrates the value of mixed methods where field observations and chemical analysis are combined with information from local people.

scholarly journals Holocene hydrological changes in the Rhône River (NW Mediterranean) as recorded in the marine mud belt

2016 ◽  
Vol 12 (7) ◽  
pp. 1539-1553 ◽  
Author(s):  
Maria-Angela Bassetti ◽  
Serge Berné ◽  
Marie-Alexandrine Sicre ◽  
Bernard Dennielou ◽  
Yoann Alonso ◽  
...  
Keyword(s):  
North Atlantic ◽  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Progressive Increase ◽  
Ice Age ◽  
Sediment Delivery ◽  
The North ◽  
Catchment Areas ◽  
The North Atlantic ◽  
The Impact

Abstract. Expanded marine Holocene archives are relatively scarce in the Mediterranean Sea because most of the sediments were trapped in catchment areas during this period. Mud belts are the most suitable targets to access expanded Holocene records. These sedimentary bodies represent excellent archives for the study of sea–land interactions and notably the impact of the hydrological activity on sediment accumulation. We retrieved a 7.2 m long sediment core from the Rhône mud belt in the Gulf of Lions in an area where the average accumulation rate is ca. 0.70 m 1000 yr−1. This core thus provides a continuous and high-resolution record of the last 10 ka cal BP. A multiproxy dataset (XRF core scan, 14C dates, grain size and organic-matter analysis) combined with seismic stratigraphic analysis was used to document decadal to centennial changes in the Rhône hydrological activity. Our results show that (1) the early Holocene was characterized by high sediment delivery likely indicative of local intense (but short-duration) rainfall events, (2) important sediment delivery around 7 ka cal BP presumably related to increased river flux, (3) a progressive increase in continental/marine input during the mid-Holocene despite increased distance from river outlets due to sea-level rise possibly related to higher atmospheric humidity caused by the southward migration of the storm tracks in the North Atlantic, (4) multidecadal to centennial humid events took place in the late Holocene. Some of these events correspond to the cold periods identified in the North Atlantic (Little Ice Age, LIA; Dark Ages Cold Period) and also coincide with time intervals of major floods in the northern Alps. Other humid events are also observed during relatively warm periods (Roman Humid Period and Medieval Climate Anomaly).

scholarly journals Interactions between fine-grained sediment delivery, river bed deposition and salmonid spawning success

2015 ◽  
Vol 367 ◽  
pp. 199-206 ◽  
Author(s):  
I. Pattison ◽  
D. A. Sear ◽  
A. L. Collins ◽  
J. I. Jones ◽  
P. S. Naden
Keyword(s):  
Suspended Sediment ◽  
Discrete Event ◽  
Survival Rates ◽  
Fine Sediment ◽  
Egg Survival ◽  
Egg Development ◽  
Sediment Delivery ◽  
Modelling Framework ◽  
River Bed ◽  
The Impact

Abstract. Salmonids clean river bed gravels to lay their eggs. However, during the incubation period fine sediment infiltrates the bed. This has been found to limit the success of salmonid spawning, as fine sediment reduces gravel permeability resulting in intra-gravel flow velocities and O2 concentrations decreasing. The success of salmonid spawning is therefore a function of the coincidence of fine sediment delivery and the development of the salmonid eggs. The presence of fine sediment also exerts sub-lethal effects on the rate of egg development with a negative feedback slowing and extending the incubation process meaning the eggs are in the gravels for longer and susceptible to more potential sediment delivery events. The SIDO (Sediment Intrusion and Dissolved Oxygen)-UK model is a physically-based numerical model which simulates the effect of fine sediment deposition on the abiotic characteristics of the salmonid redd, along with the consequences for egg development and survival. This model is used to investigate the interactions and feedbacks between the timing and concentrations of suspended sediment delivery events, and the deposition of fine sediment within the gravel bed, and the consequences of this on the rate of egg development and survival. The model simulations suggest that egg survival is highly sensitive to suspended sediment concentrations, particularly to changes in the supply rate of sand particles. The magnitude, frequency and specific timing of sediment delivery events effects egg survival rates. The modelling framework is also used to investigate the impact of the rate of gravel infilling by sediment. The hypotheses of continual, discrete event and non-linear decline in the rate of infilling are investigated.

scholarly journals Rainfall and water yield in Macizo del Caroig, Eastern Iberian Peninsula. Event runoff at plot scale during a rare flash flood at the Barranco de Benacancil

2021 ◽  
Author(s):  
A. Cerdà ◽  
A. Novara ◽  
P. Dlapa ◽  
M. López-Vicente ◽  
X. Úbeda ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Flash Flood ◽  
Point Of View ◽  
Water Yield ◽  
Research Station ◽  
Water Delivery ◽  
Sediment Delivery ◽  
Rainfall Events ◽  
Runoff Discharge ◽  
The Impact

Floods are a consequence of extreme rainfall events. Although surface runoff generation is the origin of discharge, flood research usually focuses on lowlands where the impact is higher. Runoff and sediment delivery at slope and pedon scale receiving much less attention in the effort to understand flood behaviour in time and space. This is especially relevant in areas where, due to climatic and hydrogeological conditions, streams are ephemeral, so-called dry rivers (“wadis”, "ramblas" or “barrancos”) that are widespread throughout the Mediterranean. This paper researches the relationship between water delivery at pedon and slope scale with dry river floods in Macizo del Caroig, Eastern Iberian Peninsula. Plots of 1x1, 1x2, 1x4, and 2x8 m located in the “El Teularet” Soil Erosion and Degradation Research Station were monitored from 2004 to 2014 to measure soil and water delivery. Rainfall and flow at the dry river Barranco de Benacancil were also monitored. Results show that runoff and sediment discharge were concentrated in few events during the 11 years of research. A single flood event was registered in the channel on September 28, 2009, however, the runoff was registered 160 times at the plots. Runoff discharge was dependent on the size of the plots, with larger plots yielding lower runoff discharge per unit area, suggesting short runoff-travel distance and duration. Three rainfall events contributed with 26% of the whole runoff discharge, and five achieved 56% of the runoff. We conclude that the runoff generated at the plot scale is disconnected from the main channel. From a spatial point of view, there is a decrease in runoff coefficient along the slope. From a temporal point of view, the runoff is concentrated in a few rainfall events. These results show that the runoff generated at plot and slope scale does not contribute to the floods except for rainfall events with more than 100 mm day-1. The disconnection of the runoff and sediment delivery is confirmed by the reduction in the runoff delivery at plot scale due to the control of the length of the plot (slope) on the runoff and sediment delivery.

Impact of fires, earthquakes, and climate on catchment response since 600 CE, Pallett Creek, San Gabriel Mountains, Southern California USA

2021 ◽  
Author(s):  
Katherine Scharer ◽  
Jenifer Leidelmeijer ◽  
Matthew Kirby ◽  
Nicole Bonuso ◽  
Devin McPhillips
Keyword(s):  
Southern California ◽  
Active Regions ◽  
Ice Age ◽  
Sedimentation Rates ◽  
Sediment Delivery ◽  
San Gabriel Mountains ◽  
High Sedimentation ◽  
Landscape Response ◽  
Tectonically Active ◽  
The Impact

<div> <p>In tectonically active regions, sedimentary records are overprinted by landscape response to climate, fire, and local earthquakes.  We explore this issue using a new paleoclimate record developed at the Pallett Creek paleoseismic site in southern California USA, a recently incised distal fan located along the San Andreas Fault at the base of a 35 km<sup>2</sup> catchment in the San Gabriel Mountains.  To date, we have analyzed 6 m of section, spanning the last 1300 yr, for grain size, total organic material (TOM), carbon/nitrogen (C/N) ratios, magnetic susceptibility, and charcoal count. Existing C-14 dates (Scharer et al., 2011) inform rates of sediment deposition and charcoal accumulation (CHAR). Additional dating and macrofossil analysis is ongoing.  Sedimentological variability within the section is dominated by two general units. Unit 1 is characterized by high % clay, % silt, and % TOM, while Unit 2 is distinctly coarser with higher % sand and lower % TOM.  Pulses of high CHAR occur from 1150-1260 yr BP and during the Little Ice Age (100-500 yr BP) and are associated with high sedimentation rates (0.3-2 cm/yr), while only a few relatively weak fire episodes are recorded in the Medieval Climate Anomaly (700-1000 yr BP), despite similarly high sedimentation rates (0.6 cm/yr).  Ten earthquakes documented at the site (Sieh et al., 1989) occurred about every 135 years and impart no obvious short-term impact on sedimentation rates, perhaps reflecting the distance between the site and steeper portions of the drainage network (>4 km) likely to produce mass wasting.  Overall, the landscape response of this large, integrated catchment appears to reflect a stronger influence of fire and climate than earthquakes. Future work will focus on the impact of the fire episodes on sediment delivery and resultant paleoearthquake ages.</p> </div>

scholarly journals Holocene hydrological changes of the Rhone River (NW Mediterranean) as recorded in the marine mud belt

2016 ◽  
Author(s):  
M. A. Bassetti ◽  
S. Berné ◽  
M. A. Sicre ◽  
B. Dennielou ◽  
Y. Alonso ◽  
...  
Keyword(s):  
North Atlantic ◽  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Progressive Increase ◽  
Ice Age ◽  
Sediment Delivery ◽  
The North ◽  
Catchment Areas ◽  
The North Atlantic ◽  
The Impact

Abstract. Expanded marine Holocene archives are relatively scarce in the Mediterranean Sea because most of the sediments were trapped in catchment areas during this period. Mud belts are most suitable targets to access expanded Holocene records. These sedimentary bodies represent excellent archives for the study of sea-land interactions and notably the impact of the hydrological activity on sediment accumulation. We retrieved a 7.2 m-long sediment core from the Rhone mud belt in the Gulf of Lions in an area where the average accumulation rate is of ca. 0.70 m/1000 years. This core thus provides a continuous and high-resolution record of the last 10 ka cal BP. A multi-proxy dataset (XRF-core scan, 14C dates, grain size and organic matter analysis) combined with seismic stratigraphic analysis was used to document decadal to centennial changes of the Rhone hydrological activity. Our results show that 1) the Early Holocene was characterized by high sediment delivery likely indicative of local intense (but short duration) rainfall events , 2) important sediment delivery around 7 ka cal BP roughly presumably related to increased river flux, 3) a progressive increase of continental/marine input during the Mid-Holocene despite increased distance from river outlets due to sea-level rise possibly related to higher atmospheric humidity caused by the southward migration of the storm tracks in the North Atlantic, 4) multi-decadal to centennial humid events in the Late Holocene. Some of these events correspond to the cold periods identified in the North Atlantic (Little Ice Age, LIA; Dark Age) and also coincide with time intervals of major floods a in the Northern Alps. Other humid events are also observed during relatively warm periods (Roman Humid Period and Medieval Climate Anomaly).

scholarly journals Catchment Sediment Dynamics and the Role of Deep-Seated Landslide-Dams; Waipaoa Catchment, Raukumara Peninsula, New Zealand

2021 ◽  
Author(s):  
◽  
Richard James Taylor
Keyword(s):  
Sediment Transport ◽  
Large Scale ◽  
Gully Erosion ◽  
Sediment Dynamics ◽  
Storm Events ◽  
14C Dating ◽  
Sediment Delivery ◽  
Ground Shaking ◽  
Landslide Dams ◽  
The Impact

<p>Sediment volumes retained by landslide-dams of the Waipaoa are small at 1.85x10⁶m³ compared to the 24.5km³ (Marden et al., 2008b) of sediment eroded in the landscape since the last glacial maximum. Landslide-dams do however represent a major perturbation to sediment transport, although due to their mainly short life span this disruption is discontinuous representing a pulsing in the transport network. The objective of this study is to investigate the sedimentary dynamics of the Waipaoa catchment by providing insights into the role that deep-seated landslides play and asks the questions: What is the impact on sediment transport imposed by the landslide-dams of the Waipaoa catchment? and; What do the sediments impounded in landslide-dammed lakes tell us about catchment sediment dynamics through time? The Waipaoa River on the East Cape of New Zealand‘s North Island delivers volumes of sediment to the coast which are considered high by global standards. Catchment erosion is controlled by soft marine sediments, combined with a history of tectonic fracturing and frequent intense rain storms. Erosion events are driven by intense cyclonic systems rain storms which deliver ≥200mm/24hr rainfall and induce catchment wide gully erosion as well as shallow surficial landslides. Under current land covers gully erosion provides the dominant source of sediments, with high degrees of slope channel coupling and steep gradient river profiles providing for efficient delivery to the coast. Offshore in the Poverty Bay, sediments delivered by the Waipaoa River show considerable variability over a range of temporal scales. Valley slopes within the Waipaoa catchment are also susceptible to large deep-seated landslide failures, with movement depths greater than 5 metres often on internal structural failure planes. These large slope movements can be produced by both extreme storm events (≥300mm/24hr) which occur on a return periods of 1 in 5 years and seismic ground shaking of 1 in 1000-2000 years. Where these large events block channels and are able to persist for long periods, sediments accumulated upstream to provide a unique record of the catchments sedimentary history. There have been some 1100 historic large scale features which have been identified within the Waipaoa region, with this study selecting seven that have shown evidence of channel blockage. The project aims to provide insights into the age of a sample of deep-seated landslides that have dammed channels to determine how long landslide-dams survive in the landscape and quantify the volumes of sediment they have trapped. Further, the project aims to determine what the spatial and temporal distribution of these blockages has meant to sediment delivery and whether there have been changes in sediment dynamics in their upper catchments over time. The project uses the detailed mapping of the trapped body of sediments, GIS modelling of the palaeo and present landscapes and age control determinations provided by tephra and 14C dating to provide both volumes and rates of sediment delivery.</p>

Multiple hydroclimatic controls over recent sedimentation in proglacial Mirror Lake, southern Selwyn Mountains, Northwest Territories

2005 ◽  
Vol 42 (9) ◽  
pp. 1589-1599 ◽  
Author(s):  
Jessica D Tomkins ◽  
Scott F Lamoureux
Keyword(s):  
Northwest Territories ◽  
Summer Temperature ◽  
Sedimentary Record ◽  
Sediment Delivery ◽  
Late 20Th Century ◽  
Glacial Meltwater ◽  
Varve Thickness ◽  
Mirror Lake ◽  
Decadal Scale ◽  
The Impact

Varves from Mirror Lake, Northwest Territories (62°N, 128°W) reveal significant, but changing climatic influences on discharge and sedimentation on a decadal scale during the late 20th century. The complex hydroclimatic signal within the sediments indicates the difficulty in identifying a quantitative relationship between varve thickness and a single climatic variable. Regression of recent varve thickness with local meteorological data shows July temperature as the dominant control over sediment accumulation. In contrast, the dampening effects of increased snowfall on glacier ablation and resultant runoff reduce sediment delivery. Although the impact of snowfall does not appear to significantly weaken the relationship between summer temperature and varve formation, periods when multiple climatic factors control sediment delivery are characterized by distinctive varves containing two prominent silt units. Thus, the Mirror Lake hydrological system appears to shift between two general states. The first state involves a pronounced summer glacial meltwater phase due to dominant summer temperature influences on glacial melt, resulting in varves with one silt unit. This varve structure dominates the sedimentary record from A.D. 1670 to 1941, possibly reflecting a Little Ice Age influence in the study area. The second state operates in years when glacial meltwater discharge is delayed until August, due to increased snow cover, and the lake receives increased sediment-poor nival melt. These conditions lead to the formation of varves with two silt units corresponding to nival and glacial discharge phases and are common in the sedimentary record from A.D. 1390 to 1669 and A.D. 1942 to 1996.

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