Environmental factors determining the distribution pattern of leeches (Clitellata: Hirudinida) in large river systems: A case study of the Oder River system

Biologia ◽  
2017 ◽  
Vol 72 (4) ◽  
Author(s):  
Izabela Jabłońska-Barna ◽  
Aleksander Bielecki ◽  
Joanna M. Cichocka ◽  
Edyta Buczyńska ◽  
Pawel Buczyński ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Structural Changes ◽  
River System ◽  
Large River ◽  
Taxonomic Structure ◽  
Human Pressure ◽  
Habitat Types ◽  
Oder River

AbstractThe largest rivers in Europe are under strong human pressure, resulting in habitat changes and consequently in structural changes in the quantitative and qualitative composition of fauna assemblages. The aim of this study was to identify the taxonomic structure of leech assemblages and the main environmental factors influencing their distribution pattern on a 306 km stretch of the Oder River encompassing different habitat types. Representatives of 28 leech taxa were recorded in 527 samples of bottom macrofauna. The most abundant and most frequently recorded species was the eurytopic

scholarly journals Rapid-Survey Methodology to Assess Litter Volumes along Large River Systems—A Case Study of the Tamsui River in Taiwan

2021 ◽  
Vol 13 (16) ◽  
pp. 8765
Author(s):  
Falk Schneider ◽  
Alexander Kunz ◽  
Chieh-Shen Hu ◽  
Ning Yen ◽  
Hsin-Tien Lin
Keyword(s):  
Survey Methodology ◽  
River Mouth ◽  
River System ◽  
Large River ◽  
Plastic Pollution ◽  
Current Assessment ◽  
Single Use ◽  
Polluted Rivers ◽  
Derelict Fishing Gear

Riverbanks are an important source of plastic pollution. However, the current assessment methods for riverbank litter are based on a point-based sampling which is time consuming and limited in scope. To quickly assess hotspot areas and litter compositions in larger areas, this study developed a new citizen science bicycle survey for riverine debris. Covering 281.5 km of the Tamsui river system in Taiwan, the new methodology was tested at one of the most plastics polluted rivers in the world. The results revealed an average litter density of 15.3 m3/km at the river mouth and of 0.2 m3/km to 2.8 m3/km along the riverbanks further upstream. The coastline was mainly polluted by derelict fishing gear whereas single-use plastics and illegally dumped waste dominated the upstream areas. A correlation between litter and population density could not be identified, but it was noted that litter hotspots occur at cut banks and near mangrove vegetation. Overall, the new methodology proved suitable to collect large quantities of data for scientific purposes and to quickly detect litter accumulations prior to clean-up activities.

Key Construction Technologies for Large River-Crossing Slurry Shield Tunnel: Case Study

2021 ◽  
Vol 34 (2) ◽  
pp. 04020118
Author(s):  
Song Zhou ◽  
Guan-Lin Ye ◽  
Lei Han ◽  
Wang Jian-Hua
Keyword(s):  
Large River ◽  
Shield Tunnel ◽  
Slurry Shield

scholarly journals Getting information on suspended sediments in a large river from acoustic backscatter

2018 ◽  
Vol 40 ◽  
pp. 04017
Author(s):  
Adrien Vergne ◽  
Céline Berni ◽  
Jérôme Le Coz
Keyword(s):  
Suspended Sediment Concentration ◽  
Spatial Information ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Large River ◽  
Acoustic Backscatter ◽  
Qualitative Information ◽  
Sediment Size ◽  
The Common

There has been a growing interest in the last decade in extracting information on Suspended Sediment Concentration (SSC) from acoustic backscatter in rivers. Quantitative techniques are not yet effective, but acoustic backscatter already provides qualitative information on suspended sediments. In particular, in the common case of a bi-modal sediment size distribution, corrected acoustic backscatter can be used to look for sand particles in suspension and provide spatial information on their distribution throughout a river crosssection. This paper presents a case-study where these techniques have been applied.

scholarly journals Rural-Spatial Restructuring Promoted by Land-Use Transitions: A Case Study of Zhulin Town in Central China

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 234
Author(s):  
Dong Han ◽  
Jiajun Qiao ◽  
Qiankun Zhu
Keyword(s):  
Land Use ◽  
Rural Development ◽  
Structural Changes ◽  
Land Use Changes ◽  
Central China ◽  
Rural Space ◽  
Spatial Restructuring ◽  
Local Actors ◽  
The Impact

Rural-spatial restructuring involves the spatial mapping of the current rural development process. The transformation of land-use morphologies, directly or indirectly, affects the practice of rural restructuring. Analyzing this process in terms of the dominant morphology and recessive morphology is helpful for better grasping the overall picture of rural-spatial restructuring. Accordingly, this paper took Zhulin Town in Central China as a case study area. We propose a method for studying rural-spatial restructuring based on changes in the dominant and recessive morphologies of land use. This process was realized by analyzing the distribution and functional suitability of ecological-production-living (EPL) spaces based on land-use types, data on land-use changes obtained over a 30-year observation period, and in-depth research. We found that examining rural-spatial restructuring by matching the distribution of EPL spaces with their functional suitability can help to avoid the misjudgment of the restructuring mode caused by the consideration of the distribution and structural changes in quantity, facilitating greater understanding of the process of rural-spatial restructuring. Although the distribution and quantitative structure of Zhulin’s EPL spaces have changed to differing degrees, ecological- and agricultural-production spaces still predominate, and their functional suitability has gradually increased. The spatial distribution and functional suitability of Zhulin are generally well matched, with 62.5% of the matched types being high-quality growth, and the positive effect of Zhulin’s spatial restructuring over the past 30 years has been significant. We found that combining changes in EPL spatial area and quantity as well as changes in functional suitability is helpful in better understanding the impact of the national macro-policy shift regarding rural development. Sustaining the positive spatial restructuring of rural space requires the timely adjustment of local actors in accordance with the needs of macroeconomic and social development, and a good rural-governance model is essential.

Evaluation of catchment hydrology and soil loss in non-perennial river system: a case study of Subarnarekha Basin, India

2021 ◽  
Author(s):  
Rituparna Acharyya ◽  
Niloy Pramanick ◽  
Subham Mukherjee ◽  
Subhajit Ghosh ◽  
Abhra Chanda ◽  
...  
Keyword(s):  
Soil Loss ◽  
River System ◽  
Catchment Hydrology ◽  
System A

scholarly journals Inverse Problem for Looped River Networks – Lower oder River Case Study

2013 ◽  
Vol 39 (1) ◽  
pp. 105-118
Author(s):  
Jacek Kurnatowski
Keyword(s):  
Mathematical Modeling ◽  
Flow Resistance ◽  
Flow Distribution ◽  
River Networks ◽  
Sensitivity Equation ◽  
Flow Measurements ◽  
Sensitivity Equation Method ◽  
Coefficients Identification ◽  
Oder River

Abstract Identification of coefficients determining flow resistance, in particular Manning’s roughness coefficients, is one of the possible inverse problems of mathematical modeling of flow distribution in looped river networks. The paper presents the solution of this problem for the lower Oder River network consisting of 78 branches connected by 62 nodes. Using results of six sets of flow measurements at particular network branches it was demonstrated that the application of iterative algorithm for roughness coefficients identification on the basis of the sensitivity-equation method leads to the explicit solution for all network branches, independent from initial values of identified coefficients.

Sign in / Sign up

Export Citation Format

Share Document