Sediment Accumulation in Tillamook Bay, Oregon: Natural Processes versus Human Impacts

An important goal of this book has been to provide a comprehensive understanding of the physical geography and landscape origins of South America as important background to assessing the probabilities and consequences of future environmental changes. Such background is essential to informed discussions of environmental management and the development of policy options designed to prepare local, national, and international societies for future changes. A unifying theme of this book has been the elucidation of how natural processes and human activities have interacted in the distant and recent past to create the modern landscapes of the continent. This retrospective appreciation of how the current landscapes have been shaped by nature and humans will guide our discussion of possible future trajectories of South American environments. There is abundant evidence from all regions of South America, from Tierra del Fuego to the Isthmus of Panama, that environmental change, not stasis, has been the norm. Given that fact, the history, timing, and recurrence intervals of this dynamism are all crucial pieces of information. The antiquity and widespread distribution of changes associated with the indigenous population are now well established. Rates and intensities of changes related to indigenous activities varied widely, but even in regions formerly believed to have experienced little or no pre-European impacts we now recognize the effects of early humans on features such as soils and vegetation. Colonization by Europeans mainly during the sixteenth century modified or in some cases replaced indigenous land-use practices and initiated changes that have continued to the present. Complementing these broad historical treatments of human impacts, other chapters have examined in detail the environmental impacts of agriculture (chapter 18) and urbanism (chapter 20), and the disruptions associated with El Niño–Southern Oscillation events. The goal of this final synthesis is to identify the major drivers of change and to discuss briefly their likely impacts on South American environments and resources in the near and medium-term future. Our intent is not to make or defend predictions, but rather to identify broad causes and specific drivers of environmental change to inform discussions of policy options for mitigating undesirable changes and to facilitate potential societal adaptations to them.

Is ‘re-mobilisation’ nature restoration or nature destruction? A commentary

Journal of Coastal Conservation ◽

10.1007/s11852-019-00716-9 ◽

2019 ◽

Vol 23 (6) ◽

pp. 1093-1103 ◽

Cited By ~ 8

Author(s):

Irene Delgado-Fernandez ◽

Robin G. D. Davidson-Arnott ◽

Patrick A. Hesp

Keyword(s):

Human Impacts ◽

Plant Cover ◽

Coastal Dunes ◽

Management Approach ◽

Natural Processes ◽

Bare Sand ◽

Mechanical Removal ◽

Nature Restoration ◽

Dune Form ◽

Reduced Mobility

Abstract Coastal dunes are experiencing increases in vegetation cover and reduced mobility levels in many sites around the world. Ecology-led approaches to coastal dune management perceive this change as ‘undesirable’ because the increase in plant cover leads to a reduction in partially vegetated to bare sand habitats and the species depending on them. This has generated a shift in the management paradigm where the objective is to revert this trend by intervening in the landscape, with actions ranging from re-introducing grazing and mowing, to mechanical removal of dune form and vegetation (dune ‘rejuvenation’). In some cases, such as many coastal dunes in Britain, this has also led to low controls on visitor pressure and allowing/promoting human trampling as a ‘natural’ way to free up areas of bare sand. This commentary critically analyses the main principles (and terminology) underlying this relatively recent shift in management paradigm, and questions assumptions such as ‘bare sand is good’ and/or ‘mobility is natural’ in the context of dune evolutionary cycles and responses to abiotic and biotic drivers. We review the limitations and dangers of this approach and argue that it is not sustainable given the current climatic and environmental conditions, and that it can increase the risk of coastal erosion and force dune systems to deviate from adapting and changing to direct/indirect drivers. Finally, we present the benefits of a management approach that focuses on minimizing human impacts so that natural processes continue to occur.

CHARACTERIZING HOLOCENE SEDIMENT ACCUMULATION AND HUMAN IMPACTS IN AN UPLAND KETTLE POND IN EASTERN CONNECTICUT

10.1130/abs/2018ne-311353 ◽

2018 ◽

Author(s):

William B. Ouimet ◽

◽

Caitlin T. McManimon ◽

Heather Scofield ◽

Billy Stansfield ◽

...

Keyword(s):

Human Impacts ◽

Sediment Accumulation ◽

Holocene Sediment

Recent geomorphic evolution of the fan delta of the Mornos river, Greece: natural processes and human impacts

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.17057 ◽

2007 ◽

Vol 40 (4) ◽

pp. 1538 ◽

Cited By ~ 3

Author(s):

E. Karymbalis ◽

K. Gaki-Papanastassiou ◽

H. Maroukian

Keyword(s):

Human Impacts ◽

River Mouth ◽

Sediment Supply ◽

Aerial Photographs ◽

Natural Processes ◽

Gulf Of Corinth ◽

Fan Delta ◽

Northern Side ◽

The Impact ◽

Comparative Examination

The Mornos river fan delta is located on the northern side of the western Gulf of Corinth is a Gilbert-type fan delta with an arcuate form characterised by the abundance of coarse sediments. In order to determine the processes which contributed in the configuration of the fan delta during the last two centuries a detailed geomorphic map was prepared depicting both the deltaic plain and the coastal zone features. Comparative examination of 1945, 1986 and 1998 aerial photographs and reliable maps of the last two centuries along with field observations detected recent changes of the fan delta. The construction of a dam in the upper reaches of the basin in 1980 has significantly decreased the sediment supply downstream and has slackened the growth of the fan delta. After 1980 the eastern distributary has been abandoned causing a 120 m retreat at the river mouth. Although a progradation rate of 4 m/year has been observed for the western active distributary in the period between 1945 and 1986, no remarkable changes have occurred since that period. Additionally, an assessment of the impact of the potential global future sea-level rise to the fan delta is attempted.

The Chorna Tysa river basin is the perspective area to extend borders of Carpathian Biosphere Reserve (CBR)

Physical Geography and Geomorphology ◽

10.17721/phgg.2018.2.12 ◽

2018 ◽

Vol 90 (2) ◽

pp. 97-111 ◽

Cited By ~ 1

Author(s):

Serhii Bortnyk ◽

Olha Kovtoniuk ◽

Illia Kravchuk ◽

Teiana Lavruk ◽

Vladlena Ostrikova ◽

...

Keyword(s):

Protected Areas ◽

River Basin ◽

Human Impacts ◽

Biosphere Reserve ◽

Natural Ecosystems ◽

Economic Activities ◽

Natural Processes ◽

Ecological Corridor ◽

Functional Zoning ◽

Economic Zones

Іn this article, we substantiate the practicability of incorporating the upper part of the Chorna Tysa river basin in to the Svydovets preservation massif (CBR). This expansion will not only increase the value of this object of protection of the natural and cultural heritage, but also will allow the introduction of semi-stationary scientific research within the practice area with the students of Taras Shevchenko National University's for the further study and monitoring of natural processes and anthropogenic influences. This territory is characterized by increased vulnerability to human impacts, therefore it is proposed to provide it with a differentiated conservation regime including planning of economic activities and implementation of constant monitoring of the state of landscapes and dangerous natural processes . We offer functional zoning based on the landscape structure of the territory with allocation of conservation, buffer and economic zones. It is proposed to include the relict subalpine glacial landscapes with mountain glacial lakes, subalpine meadows and forests that are unique to the Ukrainian Carpathians, to the protected area. The recreational potential of the territory can be realized by creating a modern European tourist and recreational infrastructure in the economic zone of Chorna Tysa village, Yasinya settlement and Rakhiv city. The restricted tourism with corresponding arrangement of a tourist and ecological routes is possible to develop in buffer and protected areas. The development of tourism infrastructure will increase the attractiveness of the area for tourists and increase the competitiveness of local communities. The unique and rare scenic landscapes of the Chorna Tysa Basin should form the basis for the creation of a The Pan European Ecological Network, since the sourses of the Tysa are a natural and cultural symbol for the countries of basin of the middle Danube. Natural conditions and resources of this region in Ukraine require special attention. In our opinion, the future ecological corridor along the whole valley of the Tysa River, which would combine the protected areas of the CBR is very relevant for all countries of the Tysa Basin. However, currently, construction of the tourist-recreation complex "Svydovets" is planned on this territory, which, judging by the detailed plan of the territory for the implementation of this project, can completely destroy the natural ecosystems of the region.

Natural Processes Versus Human Impacts During the Last Century: A Case Study of the Aliakmon River Delta

The Rivers of Greece - The Handbook of Environmental Chemistry ◽

10.1007/698_2017_470 ◽

2017 ◽

pp. 31-49 ◽

Cited By ~ 2

Author(s):

Michael Styllas

Keyword(s):

Human Impacts ◽

River Delta ◽

Natural Processes

The HydroEcoSedimentary Tool: an integrated approach to characterise interstitial processes in freshwater systems

10.5194/egusphere-egu21-345 ◽

2021 ◽

Author(s):

Roser Casas-Mulet ◽

Joachim Pander ◽

Maximilian Prietzel ◽

Juergen Geist

Keyword(s):

Water Quality ◽

Habitat Degradation ◽

Human Impacts ◽

Sediment Accumulation ◽

Integrated Approach ◽

Fine Sediment ◽

Ecological Processes ◽

Gravel Beds ◽

Fine Sediments ◽

A Site

Increased deposition of fine sediments in streams affects a range of key ecosystem processes across the sediment-water interface, and it is a critical aspect of river habitat degradation and restoration. Understanding the mechanisms leading to fine sediment accumulation along and across streambeds, and their affectation to ecological processes is therefore essential for comprehending human impacts on river ecosystems and inform river restoration. Here, we introduce the HydroEcoSedimentary Tool (HEST) as an integrated approach to assess hydro-sedimentary and ecologically relevant processes together. The HEST integrates the estimation of a range of processes occurring in the interstitial zone, including sedimentary (fine sediment accumulation and fine sediment loss upon retrieval), hydraulic (hydraulic conductivity), geochemical (water quality and temperature) and ecological (with a focus on brown trout early life stages).We tested the HEST application in two rivers with different degrees of morphological degradation in Germany. The HEST was successful in recording the set of key hydrosedimentary and ecologically relevant factors, and in providing a mechanistic linkage between and biological effect in a site-specific context. The HEST data confirmed that salmonid embryo mortality could be linked to high fine deposition in gravel beds. In addition, the HEST illustrated that such mortality could be linked explicitly to interstitial depths and to different infiltration pathways for fines (e.g. vertical vs. horizontal). Although interstitial water quality and temperature were within ecological thresholds and did not show significant differences with surface water, it was still useful to monitor such variables and to rule out any effect on mortality. Water temperature, for example, could be extremely important to detect local groundwater inputs, which has been demonstrated to have a significant effect on embryo salmonids elsewhere. The HEST also allowed accounting for the loss of fines during retrieval failure and estimating hydrological factors with the HEST illustrates its additional usefulness and reliability.Compared to other methods, the HEST expands the possibilities to monitor and quantify fine sediment deposition in streambeds by differentiating between vertical, lateral and longitudinal infiltration pathways, and distinguishing between the depth (upper vs. lower layers) at which interstitial processes occur along the streambed column.

Natural and human impacts on centennial sediment accumulation patterns on the Umpqua River margin, Oregon

Marine Geology ◽

10.1016/j.margeo.2013.04.015 ◽

2013 ◽

Vol 339 ◽

pp. 44-56 ◽

Cited By ~ 13

Author(s):

Robert A. Wheatcroft ◽

Miguel A. Goñi ◽

Kristin N. Richardson ◽

Jeffry C. Borgeld

Keyword(s):

Human Impacts ◽

Sediment Accumulation