Disturbances structuring macroinvertebrate communities in steep headwater streams: relative importance of forest clearcutting and debris flow occurrence

2010 ◽  
Vol 67 (2) ◽  
pp. 427-444 ◽  
Author(s):  
Sohei Kobayashi ◽  
Takashi Gomi ◽  
Roy C. Sidle ◽  
Yasuhiro Takemon
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Structural Changes ◽  
Headwater Streams ◽  
Channel Structure ◽  
The Other ◽  
Macroinvertebrate Communities ◽  
Flow Disturbances ◽  
Temperature Ranges ◽  
Stream Macroinvertebrate

This study shows that debris flow disturbances that alter in-channel physical conditions or displace organisms exert greater impacts on stream macroinvertebrate community structure than clearcutting disturbances that change energy inputs in steep headwater systems. We surveyed abiotic characteristics and macroinvertebrate communities of 10 steep headwater streams in central Japan that contained a chronosequence of forest stands and debris flow occurrences. Streams of recently logged forests had higher light levels, nitrate concentrations, and stream temperature ranges than streams of mature forests. Streams of middle-aged forests, which experienced debris flows in recent years (1989–1998), had lower abundance of shredders, crawlers, and headwater-adapted taxa than the other streams. A shredder taxon, Gammarus nipponensis , was completely absent in the streams with recent debris flows, despite their dominance in the other streams. Decreases of depositional environment associated with depletion of large wood and loss of channel structure as well as replacement of community members by rapid colonizers appear to be the major mechanisms of structural changes in macroinvertebrate communities affected by debris flows.

Catastrophic disturbances in headwater streams: the long-term ecological effects of debris flows and debris floods in the Klamath Mountains, northern California

2010 ◽  
Vol 67 (10) ◽  
pp. 1596-1610 ◽  
Author(s):  
Matthew R. Cover ◽  
Juan A. de la Fuente ◽  
Vincent H. Resh
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Headwater Streams ◽  
Ecological Effects ◽  
Ecosystem Structure ◽  
Northern California ◽  
Klamath Mountains ◽  
Mountainous Landscapes ◽  
Debris Floods

Debris flows and debris floods are catastrophic disturbances in steep, mountainous landscapes throughout the world, but little is known about the long-term ecological effects of these events on headwater streams. In 10 basins (10–20 km2) in the Klamath Mountains, northern California, USA, we used a space-for-time substitution to infer the long-term (10–100 years) effects of debris flows on stream ecosystem structure. Debris flows mobilized sediment and wood and removed riparian vegetation from large portions of channel networks. Stream temperatures were significantly warmer in streams that had recent debris flows (<10 years ago). Large wood, benthic organic matter, and detritivorous stoneflies were all very sparse in recent debris flow streams, suggesting that allochthonous energy pathways took decades to recover. Rainbow trout ( Oncorhynchus mykiss ) were abundant in recent debris flow streams, but populations of other vertebrates such as coastal giant salamander ( Dicamptodon tenebrosus ) and coastal tailed frog ( Ascaphus truei ) were virtually absent. Increased frequencies of catastrophic debris flows associated with forest management practices can have significant negative impacts on aquatic biodiversity in forested, mountainous landscapes.

scholarly journals Calibration of numerical models for small debris flows in Yosemite Valley, California, USA

2005 ◽  
Vol 5 (6) ◽  
pp. 993-1001 ◽  
Author(s):  
P. Bertolo ◽  
G. F. Wieczorek
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Numerical Models ◽  
Slope Instability ◽  
The Other ◽  
Single Channels ◽  
Field Observations ◽  
Analysis Model ◽  
M Cell ◽  
Yosemite Valley

Abstract. This study compares documented debris flow runout distances with numerical simulations in the Yosemite Valley of California, USA, where about 15% of historical events of slope instability can be classified as debris flows and debris slides (Wieczorek and Snyder, 2004). To model debris flows in the Yosemite Valley, we selected six streams with evidence of historical debris flows; three of the debris flow deposits have single channels, and the other three split their pattern in the fan area into two or more channels. From field observations all of the debris flows involved coarse material, with only very small clay content. We applied the one dimensional DAN (Dynamic ANalysis) model (Hungr, 1995) and the two-dimensional FLO-2D model (O'Brien et al., 1993) to predict and compare the runout distance and the velocity of the debris flows observed in the study area. As a first step, we calibrated the parameters for the two softwares through the back analysis of three debris- flows channels using a trial-and-error procedure starting with values suggested in the literature. In the second step we applied the selected values to the other channels, in order to evaluate their predictive capabilities. After parameter calibration using three debris flows we obtained results similar to field observations We also obtained a good agreement between the two models for velocities. Both models are strongly influenced by topography: we used the 30 m cell size DTM available for the study area, that is probably not accurate enough for a highly detailed analysis, but it can be sufficient for a first screening.

scholarly journals Morphometry of the relief and debris flow features on the northern slope of the Great Caucasus

2019 ◽  
Vol 487 (4) ◽  
pp. 438-442
Author(s):  
V. A. Karavaev ◽  
S. S. Seminozhenko
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
The Other ◽  
Northern Slope ◽  
Western Caucasus ◽  
Average Value ◽  
Key Characteristics ◽  
Flow Features ◽  
The Western Caucasus ◽  
Central Caucasus

The morphometric indicators of the relief significantly affect the debris flow features in the mountains. The key characteristics are the angles of inclination and height, and when considering heights in the first place we pay attention not to their absolute values, but to the nature of the distribution. In the presented study, the analysis of the numerical values of these two indicators for the Western, Central and Eastern Caucasus was carried out on the basis of the original digital model of the relief. The average value of the tilt angles in the Western Caucasus is 0,5° more than in the Central and Eastern, which contributes to more active debris flows. On the other hand, the Western Caucasus is distinguished by smaller elevation differences. From the position of this factor, the Central Caucasus is the most dangerous. Thus, the nature of the distribution of absolute altitudes, along with high forestation, neutralizes the factor of more significant angles of inclination of surfaces and causes less debris flow danger in the Western Caucasus relative to the Central and Eastern.

scholarly journals Direct field observations of massive bedload and debris-flow depositions in open check dams

2018 ◽  
Vol 40 ◽  
pp. 03003 ◽  
Author(s):  
Guillaume Piton ◽  
Firmin Fontaine ◽  
Hervé Bellot ◽  
Frédéric Liébault ◽  
Coraline Bel ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Time Lapse ◽  
Bedload Transport ◽  
The Other ◽  
Field Observations ◽  
Sediment Trapping ◽  
Check Dams ◽  
Protection Systems ◽  
Detention Basins

Sediment detention basins, also called SABO dams, are key facilities in flood protection systems of mountain catchments, specifically in torrents prone to massive bedload transport or debris flows. A better understanding of the processes generating sediment trapping is required to optimize their functioning. Two monitoring stations have been implemented in the French Alps on two torrents: the Manival (Saint-Nazaire-Les-Eymes) and the Claret (Saint-Julien-Mont-Denis). Time-lapse photos show an event depositing 10,000 m3of debris flow in a basin in less than six minutes and several events partially filling the other basin with gravel, impairing its capacity to store debris flows later. After a presentation of the catchments, this paper qualitatively analyzes the dynamics of the depositions. It highlights and stresses the consistency and differences between bedload and debris-flow deposition. Overall, despite clear differences of geomorphic activity, deposits tend to fill the trap basins just enough to enable the sediment transport continuity reestablishment through the basin. The open check dams thus play a role only provided that this continuity precondition is completed. These observations enhance our comprehension of massive sediment trapping in torrents and our capacity to better adjust trap maintenance and design to the objective sought in each site.

Choose you own scientific experiment: Triggering debris flows and flash floods

2016 ◽  
Author(s):  
Thea Turkington
Keyword(s):  
Debris Flows ◽  
Flash Floods ◽  
The Other ◽  
Background Information ◽  
Atmospheric Conditions ◽  
Scientific Experiment

Landslides and flash floods result in many fatalities around the globe. Understanding what triggers these events is therefore vital, although how to approach this problem is not straight forward. After background information for the experiment and some guidelines, two options are presented to learn more about the triggers of debris flows: (A) using rainfall or (B) the atmospheric conditions. You can then choose the option that appears more useful and interesting to you (you can always go back and read the other experiment afterwards). The article then ends with a reflection on the results.

scholarly journals Effects of multiple stressors associated with agriculture on stream macroinvertebrate communities in a tropical catchment

PLoS ONE ◽  
2019 ◽  
Vol 14 (8) ◽  
pp. e0220528 ◽  
Author(s):  
Aydeé Cornejo ◽  
Alan M. Tonin ◽  
Brenda Checa ◽  
Ana Raquel Tuñon ◽  
Diana Pérez ◽  
...  
Keyword(s):  
Multiple Stressors ◽  
Macroinvertebrate Communities ◽  
Stream Macroinvertebrate

scholarly journals Temperature effect in physicochemical and bioactive behavior of biogenic hydroxyapatite obtained from porcine bones

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. A. Forero-Sossa ◽  
J. D. Salazar-Martínez ◽  
A. L. Giraldo-Betancur ◽  
B. Segura-Giraldo ◽  
E. Restrepo-Parra
Keyword(s):  
Structural Changes ◽  
Biological Fluid ◽  
Treatment Temperature ◽  
Mineral Phase ◽  
Calcination Temperatures ◽  
Bioactive Properties ◽  
Temperature Ranges ◽  
Compositional Changes ◽  
Type Substitution ◽  
Biogenic Hydroxyapatite

AbstractBiogenic hydroxyapatite (BHAp) is a widely used material in the biomedical area due to its similarities with the bone tissue mineral phase. Several works have been spotlighted on the thermal behavior of bone. However, little research has focused on determining the influence of calcination temperature in the physicochemical and bioactive properties of BHAp. In this work, a study of the physicochemical properties’ changes and bioactive response of BHAp produced from porcine femur bones using calcination temperatures between 900 to 1200 °C was conducted. The samples’ structural, morphological, and compositional changes were determined using XRD, SEM, and FTIR techniques. XRD results identified three temperature ranges, in which there are structural changes in BHAp samples and the presence of additional phases. Moreover, FTIR results corroborated that B-type substitution is promoted by increasing the heat treatment temperature. Likewise, samples were immersed in a simulated biological fluid (SBF), following the methodology described by Kokubo and using ISO 23317:2014 standard, for 3 and 7 days. FTIR and SEM results determined that the highest reaction velocity was reached for samples above 1000 °C, due to intensity increasing of phosphate and carbonate bands and bone-like apatite morphologies, compared to other temperatures evaluated.

scholarly journals Changes in Value Orientations in Serbia, 2003–2018 . Patriarchy, Authoritarianism and Nationalism

Südosteuropa ◽  
2020 ◽  
Vol 68 (3) ◽  
pp. 408-431
Author(s):  
Irena Petrović ◽  
Marija Radoman
Keyword(s):  
Structural Changes ◽  
Empirical Studies ◽  
Value Orientations ◽  
The Other ◽  
Social Changes ◽  
Ethnic Nationalism ◽  
Political Situation ◽  
Other Hand ◽  
The Social ◽  
Private And Public

AbstractThe authors analyze the changes in value patterns—patriarchy, authoritarianism and nationalism—in Serbia in the context of the social changes that have marked the postsocialist transformation period. They focus on the extent and intensity of two sub-patterns within each of these three basic value patterns: private and public patriarchy, general and specific authoritarianism, organic (natural) and ethnic nationalism. The conclusions about changes in these value patterns are drawn on the basis of three empirical studies conducted in 2003, 2012, and 2018. They show the prevalence of private patriarchy, general authoritarianism, and organic (natural) nationalism over their counterparts. Private patriarchy has weakened, which is largely to be explained by the significant structural changes in Serbia. On the other hand, support of general authoritarianism and organic (natural) nationalism has been on the rise, which clearly mirrors the unfavorable economic and political situation in the country.

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