Search results for "River"
showing 10 items of 564 documents
Jet interacting with vegetation in a rotating basin
2019
Contaminants, nutrients and sediment particles flow into inland and coastal water bodies often forming turbulent jets. The aim of the present research is to improve our capability to describe how jets interact with the environment they discharge into, providing useful insights for possible mitigation of undesired and harmful impacts. Here, we focus on the case of a jet interacting with an obstructed flow under the effect of the Coriolis force as is often the case with large scale rivers discharging into the sea in vegetated environments.
Selection of spawning substratum by European river lampreys (Lampetra fluviatilis) in experimental tanks
2014
The selection of spawning substratum by the river lamprey (Lampetra fluviatilis) was studied in two experimental tanks with different flow conditions. In both tanks, four gravel sizes mixed with 15% sand were available to the test animals. In the tank with the lower current speed, lampreys selected in favour of the finest (2–8 mm) gravel size available against gravel sizes 4–20 mm and 8–40 mm. Selection was also significantly different in the tank with higher current speed where selection against the medium-sized substratum (4–20 mm) was evident, but there were no differences between selection for gravel sizes 2–8 mm, 2–40 mm and 8–40 mm relative to availability. Substratum selection and ob…
Migratory behaviour and holding habitats of adult river lampreys (Lampetra fluviatilis) in two Finnish rivers
2015
The effect of environmental factors on migratory activity of adult river lampreys entering the Kalajoki and Perhonjoki, rivers in Finland, for spawning was studied using correlation and regression analyses. Telemetric tracking of 60 individuals was utilized to study the migratory patterns and holding habitat requirements of adult river lampreys. The increases in the river discharge, wind forcing towards the river mouth and speed and magnitude of river water cooling had positive effects on the numbers of lampreys entering the rivers whereas the increase in the illumination intensity of the moon had a negative effect on their migration activity. Radio-tagged lampreys typically passed slow-flo…
Investigation of a Gravel-Bed River’s Pattern Changes: Insights from Satellite Images
2021
Changes in river pattern have been documented in the literature. The recognition of islands and vegetated patches, which is indicative of the evolution processes, requires simultaneous information at different points and at different times and field studies are still difficult and scarce. The present work, focusing the attention on a gravel-bed river, explores the possibility to conduct a first-step pattern changes analysis by identifying the evolution of the morphological features and taking information of islands and vegetated patches from satellite images easily available from Google Earth. The study is conducted by combining the information taken from both the satellite images and the f…
Lotic life stages of the European river lamprey (Lampetra fluviatilis) : anthropogenic detriment and rehabilitation
2015
Zbiorowiska roślinne doliny Czerwonej Wody w Parku Narodowym Gór Stołowych
2018
The Czerwona Woda River is the main watercourse in the Stołowe Mountains National Park and drains the major part of the Stołowe Mts. It was regulated in the past, but its channel has been spontaneously naturalized. Now, managed spruce forests grow along almost the entire length of this small mountain stream. The aims of the present study were to investigate diversity of plant communities connected with the Czerwona Woda stream and to prepare detailed vegetation maps. The results obtained can potentially be a reference for future restoration projects implemented in the Stołowe Mountains National Park. As a result of vegetation mapping, there were distinguished 20 plant communities representa…
Numerical simulation of bed degradation and bed armouring
1999
Vegetation as biomaterial in Environmental Engineering
2017
It is particularly important to focus attention on environmental technology and related procedures and materials. Bioengineering techniques and materials are needed to reduce the human impact on the environment. As an example, plants and plant materials can be used for erosion control and slope protection to reduce risk events; vegetation used for green roofs and walls is also an important bioengineering measure to protect buildings and adsorbing rainwater, containing air pollution and greenhouse gas emissions, and extending roof life. The use of plants for river bank protection and erosion control has a long tradition in Europe. Literature shows that climate is one of controlling factor of…
River bed Evolution downstream a bed sill
2007
Experimental investigation of flow turbulent structure in a high-amplitude vegetated meandering laboratory flume
2018
The present work focuses on high-curved channels which are characterized by a complex flow turbulent structure. The specific aim of work is to analyze the evolution of turbulent coherent motion in the pres-ence of vegetation on the bed.