Patterns of Wood and Sediment Storage Along Debris-flow Impacted Headwater Channels in Old-growth and Industrial Forests PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Patterns of Wood and Sediment Storage Along Debris-flow Impacted Headwater Channels in Old-growth and Industrial Forests PDF full book. Access full book title Patterns of Wood and Sediment Storage Along Debris-flow Impacted Headwater Channels in Old-growth and Industrial Forests by Jeremy T. Bunn. Download full books in PDF and EPUB format.
Author: Jeremy T. Bunn
Publisher:
ISBN:
Category : Clearcutting
Languages : en
Pages : 144
Get Book Here
Book Description
Author: Jeremy T. Bunn
Publisher:
ISBN:
Category : Clearcutting
Languages : en
Pages : 144
Get Book Here
Book Description
Author: Sean J. Bennett
Publisher: American Geophysical Union
ISBN: 0875903576
Category : Science
Languages : en
Pages : 382
Get Book Here
Book Description
Published by the American Geophysical Union as part of the Water Science and Application Series, Volume 8. Riparian Vegetation and Fluvial Geomorphology presents important new perspectives for the experimentalist, the field practitioner, the theorist, and the modeler, offering a synthesis of scientific advances along with discussions of unresolved problems and research opportunities. The volume is structured in five sections.
Author: H. Habersack
Publisher: Elsevier
ISBN: 0080553591
Category : Science
Languages : en
Pages : 837
Get Book Here
Book Description
Based on the interdisciplinary approaches between earth science, engineering, physical geography, ecology and management, this text focuses on the theoretical questions, case-studies, challenges, and constraints taken from river restoration. It is illustrated with reports of new ground-breaking research covering spatial and temporal scales of physical processes in river catchments, coupling catchment and fluvial processes, grain dynamics and fluvial forms and on geo-ecology and restoration in mountain gravel-bed river environments. Each chapter includes discussions and comments providing experience and feedback from the fundamental research. This book covers scales of analysis for gravel-bed rivers, physics and modeling of processes at local and point scales, sediment delivery and storage, eco-geography and eco-hydraulics, and channel management and restoration. * Major topics in the field are presented by recognized scientific leaders * Chapters cover theories, practices, and methodologies in river management and restoration * Interdisciplinary approach includes case-studies on new, ground-breaking research
Author: Erica Lyn Bishop
Publisher:
ISBN: 9781267104069
Category : Coarse woody debris
Languages : en
Pages : 192
Get Book Here
Book Description
Despite ongoing research on many aspects of stream morphology and large wood effects on mountain stream channels, there have been no studies that quantify these variables in non-fish-bearing, extreme headwater streams. A recent outbreak of Mountain Pine Beetle (Dendroctonus ponderosae) has led to increased Lodgepole pine (Pinus contorta) mortality in the Western North America This outbreak is expected to increase input of large wood to streams in the next decade. Increased understanding of large wood and sediment interactions in small mountain streams could have broad implications in river restoration and habitat research. This study explores an area of less intensive mountain stream research by quantifying hydrologic and morphologic characteristics and large wood channel interactions in two low-order streams (Deadhorse and Lexen creeks) on the Fraser Experimental Forest, Colorado. The influence that large wood has on the study streams was observed during field investigations of hundreds of log steps, and large wood pieces forming bed, banks, and also acting as an erosional agent in the streams. In contrast to studies of larger systems, the lack of patterns and expected relationships between large wood, channel morphology and sediment storage and transport among the study streams illustrate the extent to which they may be highly influenced by local conditions, including widely variable large wood volumes and channel and valley characteristics, such as slope and valley width, between the reaches. The findings of this research show that results of prior studies in mountain streams and their subsequent generalizations regarding expected channel dynamics, large wood, and sediment characteristics may not be applicable to streams of this size and flow regime.
Author: Peter Gerard Walsh
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Over the next several decades there may be substantial pressure to extract timber from within harvest exclusion zones, or buffer strips along headwater streams to meet the projected increase in the global demand for forest products. Forest management activities have the potential to significantly modify woody debris loads in buffer strips, and thus the availability of material for recruitment into headwater streams. Therefore, it is important that forest management practices in these headwater systems take account of the role wood supplied from buffer strips play in the development of channel structure and sediment retention capacity. Most of the research on the effects of timber harvesting in buffer strips on sediment dynamics and wood accumulation in small headwater streams has been carried out in the Northern Hemisphere, in particular the Pacific Northwest of North America. Australia, in contrast to these regions, is tectonically inactive, with rivers that are characterised by highly variable flow regimes, and low sediment loads. Consequently it is likely that the drivers of erosion and sedimentation and woody debris recruitment are different. Where studies have been conducted in Australia, they have mostly been on larger systems in catchments not typical of the small headwater basins and ephemeral channels where the majority of timber harvesting in the coastal forest of New South Wales occurs. The main aim of this study is therefore to advance our understanding of the physical interactions between buffer strips and small zero order ephemeral headwater channels, and the potential impact of timber harvesting on these interactions. To address this main aim, five related research aims were proposed and focussed on: 1) assessing the characteristics of large wood pieces and their geomorphic significance in the channels; 2) identification of how, and from what distance the LW pieces were recruited to the channels; 3) measuring the impact of harvesting in the zero order basins and buffer strips along the channels; and 4) modelling the effect on channel erosion and sediment transport of in-channel obstructions created by large wood. To achieve this, five zero order channels in a native forest on the south coast of New South Wales, Australia, were instrumented with rain gauges and weirs to monitor rainfall, streamflow, turbidity, and suspended sediment concentration over a seven and a half year period. After a five year calibration period, four of the catchments were harvested, while one remained as a control. In the harvested catchments there were two replicated treatments; harvesting in the 10 m buffers, and no harvesting in the 10 m buffers. Two major methods were applied to identify interactions in the zero order channels between buffer strips and in-channel large wood obstructions, and the potential impact of timber harvesting on these interactions. The first was analysis of the effect of timber harvesting using a range of statistical techniques including generalised linear models and maximum likelihood estimation. The second method invoked a cellular landscape and river reach process model to simulate the role of channel obstructions created by large wood on channel erosion and sediment transport. The process model was parameterised and calibrated against an observed discharge and suspended sediment record. Following calibration, 12 discharge and large wood obstruction scenarios were carried out to model erosion and suspended sediment transport over a timber harvesting cycle. Results of the statistical analysis showed that harvesting had a significant impact on runoff and suspended sediment yield relative to the control, but did not have a significant impact on turbidity or suspended sediment concentration. There was no significant difference in post-harvest runoff, turbidity, suspended sediment concentration, or suspended sediment yield between the treatments. In the treatment where there was no harvesting in buffers, the significant increase in suspended sediment yield dissipated after 18 months and was accompanied by a hydrological recovery in peak flows toward pre-harvest values. In the treatment where there was harvesting in the buffers, there was no hydrological recovery in peak flows, nor was there a decrease in suspended sediment yields 18 months after harvesting. Erosion rates in the harvested catchments over the 32 month post-harvest period were three times greater than the control erosion rate, but were still less than the sustainable erosion rate recommended for Australia, and were largely in balance with regional estimates of soil production. The majority of large wood interacting with the channels, and forming obstructions behind which sediment was stored had diameters ≤ 30 cm. Most of this wood was being delivered from the channel margins within the buffer strips. Most of the sediment within the zero order channels was stored on the channel bed, and was an order of magnitude greater than the amount of sediment stored behind obstructions. Of the sediment stored behind obstructions, large wood provided the majority of storage sites. The use of the process model to increase and extend the observed discharge record provided some useful insights into the temporal and spatial pattern of erosion, sediment storage and transport, and complimented the statistical analysis of harvesting impacts by extending these processes over a harvesting cycle. The benefit of retaining buffers alongside the zero order channels was demonstrated by a substantial reduction in channel erosion and suspended sediment yield obtained through the inclusion of in-channel large wood obstructions in the cellular landscape and river reach model. Therefore it is important that harvesting practices maintain sufficient volume of standing wood in these buffer strips alongside zero order channels to ensure ongoing recruitment of large wood to the channel network. The management implications of this study are not just relevant for coastal New South Wales, but also for other catchments where their hydroclimatologies may produce similar results.
Author: Evan A. Hart
Publisher:
ISBN:
Category : Debris avalanches
Languages : en
Pages : 310
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Forest drainage
Languages : en
Pages : 172
Get Book Here
Book Description
Author: Gordon E. Grant
Publisher:
ISBN:
Category : Aerial photography in forestry
Languages : en
Pages : 44
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Great Smoky Mountains National Park (N.C. and Tenn.)
Languages : en
Pages : 90
Get Book Here
Book Description
In the early 1900s, large sections of the Great Smoky Mountains were in- tensively logged. Since then, most locations have been allowed to naturally become forest-covered again, resulting in areas of secondary growth and old growth forest. To determine whether dierences in large woody debris (LWD) loading and channel morphology persist today, I measured LWD, channel widths and depths, and channel bed sediments of streams in old and secondary growth forest in the Great Smoky Mountains National Park. LWD pieces in streams in old growth had larger mean diameters and lengths compared to LWD in streams in secondary growth forest. Streams in old growth had 5.6 times more LWD volume than those in secondary growth. More LWD pieces were in debris dams in old growth than in secondary growth forest. Channel bed sediment size did not dier signicantly between streams in old and secondary growth forest. Channel widths and depths were signicantly larger in streams in old growth forest. LWD pieces aected channel depth primarily by creating pools and causing deposition of sediment. LWD aected width by directing stream ow toward banks and by protecting banks from erosion. I observed that the orientation of LWD was important in determining its geomorphic role. Although I found no relationship between LWD loading and watershed area, I found a relationship between watershed area and the importance of LWD in impacting channel morphology. Despite dierences in LWD frequency and total volume, streams in old and secondary growth forest diered little in width and depth in the largest watersheds in this study. However, in smaller watersheds, streams in old growth were not as narrow or as shallow as streams in secondary growth. LWD loading can vary substantially between streams, even those with similar surrounding forest types, climate, and disturbance histories; therefore, caution should be exercised when using LWD loading rates from other studies in environmental management. Despite nearly 80 years of forest regrowth, LWD loading and channel morphologies of streams still show the impacts of logging.
Author: Melissa A. Maxa
Publisher:
ISBN:
Category : Coarse woody debris
Languages : en
Pages : 226
Get Book Here
Book Description
