Model test of concentration variation effect of suspended load in rivers

The main aim of the article is to show (present) the influence of vegetation zone on concentration of suspended load. New standards (principles, rules) of river engineering conducted in harmony with nature assign enormous plant significance. It is treated not only as a natural factor but also as a component of hydraulic reaction which clearly shapes hydraulic and hydrologic conditions. Until recently it was generally believed that vegetation is only the faktor which makes exploatation of water facilities difficult and unfavourably influence on structure working. At present vegetation has begun to be appreciated as a new element in contemporaly water management which may favourably influence on hydraulic conditions. Vegetation may cause riverbed roughness changes, bed configuration changes, water level slope changes increase of riverbed erosion resistance and also may cause retention of considerable amount of suspended load transported by (in) the river. Existing of vegetation zone in rivers and reservoirs influences on fluvial processes. Vegetation degree and its vertical and horisontal dimension influence on longitudinal and transverse transport of suspended load as well as its variation dynamics. The research of the suspended load transoport in vegetation zone was conducted in Institute of Environmental Engineering on model in scale 1:1. The ...

Characteristic parameters for vegetation density description in river beds

In the paper some the most important, characteristic parameters for vegetation density description are presented. The density of vegetation in the river beds is one of the most important parameters that has impact on the flow conditions in the river. The mathematical formulae for flow resistance and water level calculations contain the density of vegetation zone as a parameter. This parameter can be described by various methods. The compact specification of plants parameters is given in the paper. ...

The influence of vegetation on velocity profiles in small river

Vegetation growing in the River Bed is strongly influencing flowing condi-tion. Effective flow section is reduced, velocity field is disturbed and flow resistance is increased. Its consequence is change of water level and depth in comparison with flow in river bed without vegetation.Equations of momentum conservation in river bed with trees based on a concept of whirly viscosity proposed by Rowiński and Kubrak [2002] are one of mathematical description of vegetation hydraulic influence. Above equations were solved using implicit and explicit differential scheme to determine flow velocities distribution in vertical profile. Accuracy of proposed algorithms was tested by comparing numerical solutions with detailed analytical solution obtaining very good conformity. Velocity distribution calculated on the base of the model was used to determine volume of the flow. To evaluate possibilities of using developed model for calculation concern-ing small rivers with vegetation, some filed investigation on one section of Ślęganina river were carried out. Despite of geodetic measurements, some profiles of local flow velocities for vegetated and free of plants sections were made. Field measurements results were used for verification of mathematical model based on equations of momentum conservation.     ...

Ecomorphological valorization of the Oława river from km 01+400 TO 04+800

The paper presents the results of ecomorphological valorization of the left-bank tributary of the Oder River - the Oława River situated on Wrocław area in the sections from 01+400 to 04+800, between the Rakowiecki Bridge and the water-bearing areas of the city. The areas along the Oława River belong to the eco-logically valuable thanks to it biodiversity. However, their extraordinary landscape make them the subject of cultivation plans in the valley. The studied river segment was divided into 17 sections 200 m each, where hydromorphological valorization was carried out by the use of Ilnicki and Lewandowski method. The aim of the paper was the assessment of the ecological potential of river valley on the urbanized area and possibilities of maintaining natural environment in possible best condition despite of environmental hazard.     ...