An investigation into river bank erosion at Marshaw Wyre

Abstract

The process of river bank erosion is conditional to a number of different governing factors which all have a differentiating amount of influence with each specific river site. This process is especially important as it has the ability to change the very landscape in which a river flows. With reference to previous research then main components have been investigated in this paper. These include Vegetation, Bank composition, Bank angle and in channel factors such as velocity, all of which have been stated to have an impact upon the rate of bank erosion or bank stability. The paper will look at the relationships which exist between erosion and the controlling factors theorised by previous academics.

The investigation will take place on a 400 metre reach of the tributary Marshaw Wyre in the Trough of Bowland, Lancashire which is ideal due to the sinuosity of this river reach. In this study a vegetation survey was conducted using empirical sampling techniques and classified as grass, shrub or tree. The cover of vegetation was expressed as percentage on both the left and right bank meanwhile bank composition was assessed using its texture. The rest of the fieldwork data was collated using quantitative fieldwork techniques.

The Results of this study are not definitive; however it did provide insight into the relationships which are present between erosions and its controls. It was obvious that the presence of vegetation and its roots provides great stability for a river bank and greatly helped consolidate bank material. In addition, Bank composition was mostly consistent and it was identified there was a strong relationship between this and erosion.