Title: The Impact Of Grazing And Upland Management On Erosion And Runoff: Additional Information
Author: M Johns
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1440, Representation ID: 491, Object ID: 2594
Abstract:
The fundamental conclusion of this project is that the enhanced removal of vegetation: erosion of soil and rock and the consequential increased runoff of water is a widespread problem in the British uplands. Where acdemic study has failed to yield evidence of this, anecdotal and photographic evidence has managed to do so. The net effects of this enhanced erosion have severe impacts on the functions of the Environment Agency and the wider economy. It would appear that the impact of intensive grazing pressure forms a large component of the cause of the problem. However, other mechanisms do cause soil erosion in the uplands. The creation of bare soil from the effects of agents such as fire, bracken control and forestry exacerbates the impacts of other erosion mechanisms. The presence of grazing animals on such areas of bare soil increases the erosion rates and retards the return of vegetation (which has the potential to reduce erosion and runoff). In general, agriculture has become more intensive, especially in lowland areas in that stocking densities and the numbers of sheep reared have risen in some locations. However, upland farming could also be considered as extensive, in terms of mass reductions in labour. This has direct consequences for management which has effectively decreased. Therefore, uncontrolled livestock cause hotspots of grazing pressure and impacts from hooves. In the past, the managkment of the uplands and grazing animals was a sustainable, symbiotic relationship. The numbers of sheep grazed was controlled by the amount of fodder produced by the land and the ability df the farmer to transport feed to remote moortops. Today, artificial feeds are used to sustain large flocks, and All Terrain Vehicles can transport the feeds to remote areas, promoting year round grazing. Winter grazing is particularly damaging as the vegetation is not growing during this period. Long-term data sets are required to quantify the problem; these are currently unavailable. It is apparent from the review of literature conducted in Part Two of this report that the academic community has a full variety of conclusions on the subject of grazing, erosion and runoff which are often at odds with each other. The variety of findings from the study of the subject can be attributed to the scale at which the problem or process is viewed. Generally, experimental catchments are small and therefore tend to be non-representative. An overall model is required as different effects occur at different scales. To achieve this, long-term studies need to be initiated in a variety of different catchments.
Publisher: Environment Agency
Subject Keywords: Runoff; Rivers; Erosion; Livestock; Grazing; Catchment basins; Streams; Flow rate; Water levels; Flood control
Extent: 172
Permalink: http://www.environmentdata.org/archive/ealit:4682
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