Interannual kinetics (2010–2013) of large wood in a river corridor exposed to a 50-year flood event and fluvial ice dynamics

Geomorphology ◽  
2017 ◽  
Vol 279 ◽  
pp. 59-73 ◽  
Author(s):  
Maxime Boivin ◽  
Thomas Buffin-Bélanger ◽  
Hervé Piégay
2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
E. Rigon ◽  
J. Moretto ◽  
F. Delai ◽  
L. Picco ◽  
D. Ravazzolo ◽  
...  

The evaluation of the morphological quality of rivers is essential to define the level of alteration and for implementing future management strategies that consider also hazards related to fluvial processes and channel dynamics. This type of evaluation is particularly significant for the Italian rivers, that, as in many other European countries, have a very high level of human pressure. Recently, in Italy, the National Institute for Environmental Protection and Research has promoted a methodology named IDRAIM for hydromorphological analysis of streams that pursues an integrated approach aimed at a harmonized implementation of both the EU Water Framework Directive (WFD, 2000/60/EC), and the EU Floods Directive (2007/60/EC). In this paper we present the application of the Morphological Quality Index (MQI) protocol, which is part of IDRAIM, to determine the assessment of the morphological quality of the Cordevole River. The water network (only collectors greater than thirdorder were considered), has been divided, through GIS software, into 132 river reaches of homogeneous morphological characteristics, according to the first phase of the method. At this stage the semi-automatic calculation of lateral confinement (defined by “degree of confinement” and a “confinement index”) was tried, in order to reduce the implementing time. The application of 28 indicators was made for 42 reaches representing the major river types and human pressures in the site investigation. The results showed that 48% of the analyzed reaches have a very good or good quality status, 38% have a moderate morphological quality, while only 14% have the characteristics of poor or very poor quality. The main causes that lead to a strong alteration of the terms of reference are linked to i) poor connectivity between hillslopes and river corridor, that is very important for the natural supply of sediment and large wood; ii) absence of vegetation in the river corridor, that is functional to a range of geomorphic processes; iii) presence of artificial elements, particularly the bedload interception structures in the catchment, bank protection along the reach, and the removal of sediment, large wood and vegetation.


<em>Abstract.</em>—We review published literature examining the role of wood in mediating biodiversity in aquatic ecosystems, identifying the components of biodiversity, taxonomic groups, and scales that have been studied, and highlight gaps in existing knowledge. The components of biodiversity most frequently studied include species diversity (or richness) of macroinvertebrates and fishes, structural complexity within habitat units, and the diversity of habitats found in a stream reach. Many of these studies show that large wood increases biodiversity by providing stable, hard substrates for colonization by periphyton and macroinvertebrates; by increasing microhabitat complexity; and by shaping channel morphology by controlling patterns of erosion and deposition in stream reaches. The abundance of wood in channels, as well as its functional role, varies greatly in longitudinal, lateral, and vertical dimensions along the river corridor. The influence of wood on community structure and ecosystem processes also varies across these dimensions and from stream headwaters to river mouths and nearshore marine environments. Thus, wood can influence biodiversity at all of these scales. Numerous studies, however, have failed to show an effect of wood on biodiversity. These conflicting results illustrate that wood abundance, its functional role in streams, and its influence on biodiversity depend on a variety of factors, and it is the total effect of all these factors, not simply the presence of large wood, that determines patterns of biodiversity.


2016 ◽  
Vol 47 (2) ◽  
pp. 72 ◽  
Author(s):  
Lorenzo Picco ◽  
Alessia Tonon ◽  
Riccardo Rainato ◽  
Mario Aristide Lenzi

Riverine environments can be very dynamic and complex systems, particularly because of the interaction between active channel and riparian land during flood events of different magnitude. In recent years increasing attention has been paid to large wood (LW), focusing on its role and impact along riverine systems and fluvial landscapes. This research aims to analyze the characteristics of LW recruitment as a consequence of a flood event along a reach of a gravel-bed river. The study was conducted on a 3 km-long reach located in the middle course of the Piave River (north-eastern Italian Alps). A 20 m-wide buffer zone was considered along the floodplains and islands. Every standing tree in this buffer with diameter ≥0.10 m was measured manually (diameter breast height; height), whereas shrubs were not considered. The most common species in the study area are: <em>Populus</em> sp., <em>Salix</em> sp., <em>Alnus</em> sp., <em>Carpinus</em> sp., <em>Fraxinus</em> sp., <em>Pinus</em> <em>sylvestris</em> and <em>Robinia</em> <em>pseudoacacia</em>. An over bankfull flood (Q=1329 m<sup>3</sup>s<sup>–1</sup>; recurrence interval=6 years) in November 2014 caused erosions along the floodplain (15,565.5 m<sup>2</sup>), pioneer islands (25.2 m<sup>2</sup>) and building islands (2085.6 m<sup>2</sup>), recruiting 690 trees. Four of these trees were recruited from the pioneer islands (0.16 tree m<sup>–2</sup>), 79 from building islands (0.04 tree m<sup>–2</sup>) and 607 from floodplains (0.04 tree m<sup>–2</sup>). Accurate dendrometric measurements were used to define the input volume of LW from the floodplains (86.25 m<sup>3</sup>), pioneer islands (0.14 m<sup>3</sup>) and building islands (6.62 m<sup>3</sup>). The maximum distance traveled by LW recruited from the floodplain, pioneer and building islands was 8927, 1021 and 3727 m, respectively. Statistical analysis showed no significant relationship between the displacement and LW characteristics considered (diameter, length, volume, density). These results demonstrate that the recruitment and subsequent transport of LW is a complex mechanism that requires further study. To better characterize these mechanisms, it appears clear that it is important to consider not only the LW characteristics but also the connection between LW, morphological settings, and flood event characteristics.


2018 ◽  
Vol 4 (2) ◽  
Author(s):  
E. Hanggari Sittadewi

Environment degradation in Rawa Pening’s lake is caused of descend lake’s functions for some potentions and activities around the lake. Some problems in the Rawa Pening’s lake has emerged i.e : decrease water quality of lake, abundance of water hyacinth growth and increase sediment in the bottom lake. A research about infl uences of land ecosystem on Panjang and Galeh river corridors for Rawa Pening’s lake has been done. Two rivers named Galeh and Panjang are the largest water contribution in Rawa Pening’s lake. That caused the land characteristic ecosystem of that river corridors gives infl uences in the Rawa Pening’s lake.Key words: land ecosystem, river corridor, water contribution, Rawa Pening Lake.


1988 ◽  
Vol 23 (2) ◽  
pp. 243-252 ◽  
Author(s):  
J.E. Bruton ◽  
J.H. Jerome ◽  
R.P. Bukata

Abstract Satellite data from Landsats 4 and 5 were utilized to delineate the seasonal variations of sediment transport zones in the Lac Saint-Pierre region of the St. Lawrence River corridor. A seasonally cyclic succession of patterns displaying persistent, mutually independent, and extensive (in both space and time) turbidity zones was clearly in evidence. Visible and thermal data in both imagery and digital formats were used to show the close relationships existing among the distinct zonal synoptic patterns, the bathymetry of lake and river, and the near surface aquatic temperatures.


2021 ◽  
Vol 56 ◽  
pp. 102086
Author(s):  
Ismail Haltas ◽  
Enes Yildirim ◽  
Fatih Oztas ◽  
Ibrahim Demir
Keyword(s):  

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