scholarly journals Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina)

2021 ◽  
Author(s):  
Eduardo Garzanti ◽  
Tomas Capaldi ◽  
Giovanni Vezzoli ◽  
Mara Limonta ◽  
Numa Sosa
Keyword(s):  
Climate Change ◽  
Southern Andes ◽  
Sediment Routing

scholarly journals Changes in flow and sediment load of poorly gauged Brahmaputra river basin under an extreme climate scenario

2020 ◽  
Author(s):  
Shammi Haque ◽  
Md. Mostafa Ali ◽  
A. K. M. Saiful Islam ◽  
Jamal Uddin Khan
Keyword(s):  
Climate Change ◽  
River Basin ◽  
River Flow ◽  
Sediment Load ◽  
Monsoon Season ◽  
Climate Scenario ◽  
Baseline Period ◽  
Future Climate Change ◽  
Brahmaputra River ◽  
Sediment Routing

Abstract Brahmaputra River Basin (BRB), the largest contributor of sediment load in Ganges–Brahmaputra–Meghna delta, is highly vulnerable to future climate change. Several studies assessed the effects of climate change of BRB on river flow but an assessment on sediment load has not been conducted. Changes in sediment load in the future need to be assessed to control and manage sediment flows in large catchments properly. The present study focuses on developing a hydrological and sediment routing model of BRB using the HEC-HMS model to estimate future sediment load together with the flow for the RCP 8.5 climate scenario. Modified Universal Soil Loss Equation and Engelund Hansen method of HEC-HMS have been applied for the sediment transport of BRB. The model has been calibrated using daily runoff for the period 1983–1996 and validated for the period 1997–2010, respectively. The uncertainty in the percentage change in seasonal sediment load during the pre-monsoon season is higher than that of the monsoon season. However, the contribution of the sediment load of pre-monsoon is very much lower than the monsoon season. The percentage changes in mean annual sediment load compared to the baseline period for the 2020s, 2050s and 2080s are 34, 67 and 115%, respectively.

Quantifying competing measures of sediment dynamics on alluvial fans: implications for reconstructing past environmental change

2021 ◽  
Author(s):  
Alexander Whittaker ◽  
Sam Brooke ◽  
Mitch D'Arcy
Keyword(s):  
Climate Change ◽  
Grain Size ◽  
Environmental Change ◽  
Regional Climate ◽  
Sediment Dynamics ◽  
Death Valley ◽  
Shear Stresses ◽  
Alluvial Fans ◽  
Sediment Routing ◽  
Depositional Units

<p>The effects of climate change on eroding landscapes and the sedimentary record remains poorly understood. While sediment routing systems at the Earth’s surface should, in principle, record changes in past environmental boundary conditions, the extent to which landscapes are buffered to high-frequency, high-magnitude climate change is contentious. Mountain catchments and alluvial fans offer one way to address this question, as they are accessible sediment routing systems in which source and sink are closely coupled, sedimentation rates are high, and sediment budgets can be closed. Here we consider the extent to which the granulometry of sediment in stream-flow-dominated alluvial fans records changing environmental conditions. We focus on well-constrained field examples in Death Valley, California, such as the Hanaupah Canyon Fan, which have experienced hydroclimate forcing associated with recent glacial-interglacial cycles. Using field-derived measures of grain size, we compare three complementary methods that have recently been used to reconstruct sediment dynamics on alluvial fans. First, we use a self-similarity analysis of sediment calibre to reconstruct sediment mobility on the fan over time. Second, we use a downstream-fining model to evaluate the extent to which different depositional units on the fans record changing sediment fluxes from source catchments. Finally, we adopt a palaeohydrological approach to reconstruct unit discharges, bed shear stresses and instantaneous sediment transport capacities for fans in the study area, based on field measures of hydraulic geometry and grain size. We evaluate the extent to which these three methods provide consistent results, and we quantify the extent to which grain mobility, water and sediment discharge scale with documented variations in the regional climate. Our work shows that alluvial fans are highly sensitive to palaeo-environmental change, but our findings also illustrate the importance of considering which measures of past climate (particularly averages versus variance) are most relevant for landscape responses and sensitivity to climate change. </p>

Averting robo-bees: why free-flying robotic bees are a bad idea

2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin
Keyword(s):  
Climate Change ◽  
Computer Simulation ◽  
Food Security ◽  
European Countries ◽  
Plant Interactions ◽  
Plant Insect Interactions ◽  
Native Habitat ◽  
Insect Pollinators ◽  
Insect Interactions

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.

Modelling ecosystem adaptation and dangerous rates of global warming

2019 ◽  
Vol 3 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Rebecca Millington ◽  
Peter M. Cox ◽  
Jonathan R. Moore ◽  
Gabriel Yvon-Durocher
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Diffusion Rate ◽  
Individual Species ◽  
Genetic Evolution ◽  
Rates Of Change ◽  
Rapid Climate Change ◽  
Warming Climate ◽  
Intraspecies Competition ◽  
High Trait

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).

Climate change and breeding success: decline of the capercaillie in Scotland

2001 ◽  
Vol 70 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Robert Moss ◽  
James Oswald ◽  
David Baines
Keyword(s):  
Climate Change ◽  
Breeding Success

Climate Change and the Voiceless

2019 ◽  
Author(s):  
Randall S. Abate
Keyword(s):  
Climate Change

Sediment Routing Systems

2017 ◽  
Author(s):  
Philip A. Allen
Keyword(s):  
Sediment Routing
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