scholarly journals How Does Spartina alterniflora Invade in Salt Marsh in Relation to Tidal Channel Networks? Patterns and Processes

2020 ◽  
Vol 12 (18) ◽  
pp. 2983
Author(s):  
Limin Sun ◽  
Dongdong Shao ◽  
Tian Xie ◽  
Weilun Gao ◽  
Xu Ma ◽  
...  
Keyword(s):  
Spartina Alterniflora ◽  
Yellow River ◽  
Higher Order ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Channel Network ◽  
Buffer Zones ◽  
Channel Networks ◽  
Main Pathway ◽  
Patterns And Processes

Rapid invasion of Spartina alterniflora in coastal wetlands throughout the world has attracted much attention. Some field and imagery evidence has shown that the landward invasion of S. alterniflora follows the tidal channel networks as the main pathway. However, the specific patterns and processes of its invasion in salt marshes in relation to tidal channel networks are still unclear. Based on yearly satellite images from 2010 to 2018, we studied the patterning relationship between tidal channel networks and the invasion of S. alterniflora at the south bank of the Yellow River Estuary (SBYRE). At the landscape (watershed and cross-watershed) scale, we analyzed the correlation between proxies of tidal channel network drainage efficiency (unchanneled flow lengths (UFL), overmarsh path length (OPL), and tidal channels density (TCD)) and spatial distribution of S. alterniflora. At the local (channel) scale, we examined the area and number of patches of S. alterniflora in different distance buffer zones outward from the tidal channels. Our results showed that, overall, the invasion of S. alterniflora had a strong association with tidal channel networks. Watershed with higher drainage efficiency (smaller OPL) attained larger S. alterniflora area, and higher-order (third-order and above) channels tended to be the main pathway of S. alterniflora invasion. At the local scale, the total area of S. alterniflora in each distance buffer zones increased with distance within 15 m from the tidal channels, whereas the number of patches decreased with distance as expansion stabilized. Overall, the S. alterniflora area within 30 m from the tidal channels remained approximately 14% of its entire distribution throughout the invasion. The results implicated that early control of S. alterniflora invasion should pay close attention to higher-order tidal channels as the main pathway

Landscape allometry: from tidal channel hydraulic geometry to benthic ecology

2002 ◽  
Vol 59 (8) ◽  
pp. 1418-1427 ◽  
Author(s):  
W Gregory Hood
Keyword(s):  
Exit Time ◽  
Surface Velocity ◽  
Hydraulic Geometry ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Surface Deposit ◽  
Channel Size ◽  
Channel Form ◽  
Ecological Patterns ◽  
Patterns And Processes

The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it does not provide guidance for the ecological consequences of channel form. This study investigates the potential linkage of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders. These observations suggest that the highest concentrations of fish feeding in estuarine tidal channels may be in smaller channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape allometry.

Reclamation shifts the evolutionary paradigms of tidal channel networks in the Yellow River Delta, China

2020 ◽  
Vol 742 ◽  
pp. 140585 ◽  
Author(s):  
Chengjie Xie ◽  
Baoshan Cui ◽  
Tian Xie ◽  
Shuling Yu ◽  
Zezheng Liu ◽  
...  
Keyword(s):  
Yellow River ◽  
Yellow River Delta ◽  
River Delta ◽  
The Yellow River ◽  
Tidal Channel ◽  
Channel Networks ◽  
The Yellow River Delta

scholarly journals Coarse bedload routing and dispersion through tributary confluences

2016 ◽  
Vol 4 (3) ◽  
pp. 591-605 ◽  
Author(s):  
Kurt S. Imhoff ◽  
Andrew C. Wilcox
Keyword(s):  
Radio Frequency Identification ◽  
Debris Flows ◽  
Tracer Experiment ◽  
Coarse Particles ◽  
Channel Network ◽  
Spatial And Temporal Scales ◽  
Sediment Routing ◽  
Frequency Identification ◽  
Patterns And Processes ◽  
And Storage

Abstract. Sediment routing fundamentally influences channel morphology and the propagation of disturbances such as debris flows. The transport and storage of bedload particles across headwater channel confluences, which may be significant nodes of the channel network in terms of sediment routing, morphology, and habitat, are poorly understood, however. We investigated patterns and processes of sediment routing through headwater confluences by comparing them to published results from lower-gradient confluences and by comparing the dispersive behavior of coarse bedload particles between headwater confluence and non-confluence reaches. We addressed these questions with a field tracer experiment using passive-integrated transponder and radio-frequency identification technology in the East Fork Bitterroot River basin, Montana, USA. Within the confluence zone, tracers tended to be deposited towards scour-hole and channel margins, suggesting narrow, efficient transport corridors that mirror those observed in prior studies, many of which are from finer-grained systems. Coarse particles in some confluence reaches experienced reduced depositional probabilities within the confluence relative to upstream and downstream of the confluence. Analysis of particle transport data suggests that variation in the spatial distribution of coarse-sediment particles may be enhanced by passing through confluences, though further study is needed to evaluate confluence effects on dispersive regimes and sediment routing on broader spatial and temporal scales.

scholarly journals Morphometry and geomorphic development of the Bagmati River Basin, Nepal Himalaya

2013 ◽  
Vol 46 ◽  
Author(s):  
Pramila Shrestha ◽  
Naresh Kazi Tamrakar
Keyword(s):  
River Basin ◽  
Quantitative Description ◽  
Drainage System ◽  
Higher Order ◽  
Tectonic Activity ◽  
Mature Stage ◽  
Channel Network ◽  
Order Stream ◽  
Tectonic Zone ◽  
Bagmati River

Morphometric analysis of a watershed provides a quantitative description of the drainage system which is an important aspect of characterization of watershed. The analysis requires measurement of linear features, aerial aspects, gradient of channel network and contributing ground slopes of the drainage basin. The morphometric characteristics at the watershed-scale may contain important information regarding its formation and development because all hydrologic and geomorphic processes occur within the watershed. In this study morphometric property of the Bagmati River Basin (BRB) was investigated using different morphometric attributes and hypsometric analysis in order to investigate geomorphic development of the river basin, in an active tectonic zone. DEM has been prepared from the contour and spot height data using digital topographic maps of 1:25000-scale acquired from the Department of Survey, Nepal. The main stem Bagmati River is the eighth order perennial river that stretches for 206 km with an elongated catchment of area 3761 sq. km. It consists of 39 sub-basins of fourth order and higher. The study shows that the drainage system of the BRB is attaining a mature stage from a youth stage from lower order streams to the higher order streams in geomorphic development process. Some exceptions occurred at higher order stream segments, where drainage development seems to control by structure and lithology. According to the analytical results, erosional stage and level of tectonic activity of sub-basins differ from each other. Generally, the lithology and geological structure seems to control the drainage texture and relief of the BRB. The river system within the Kathmandu Valley is attaining maturity having meandering channels with wide flood plains, whereas rivers of the Lesser Himalaya and the Siwaliks are at youth stage with erosional potential. The downstream part of higher order stream segments are in mature stage having potential for lateral erosion and meander migration. Therefore, the Bagmati River stretch, especially the eight order one poses vulnerability to bank erosion.

Seafloor morphology and habitats of tidal channels in the Venice Lagoon, Italy tidal channel habitats

2020 ◽  
pp. 187-198
Author(s):  
Fantina Madricardo ◽  
Giacomo Montereale-Gavazzi ◽  
Marco Sigovini ◽  
Aleksandra Kruss ◽  
Carlotta Toso ◽  
...  
Keyword(s):  
Venice Lagoon ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Seafloor Morphology
Sign in / Sign up

Export Citation Format

Share Document