Evaluate the Evidence for Human Impacts on Downstream Flood Risk in Rural Catchment Areas in Temperate Regions
Evaluate the evidence for human impacts on downstream flood risk in rural catchments in temperate regions.
Before we can evaluate human impacts on flood risk we must first establish what is meant by temperate regions and also rural catchments. Temperate regions are generally regarded as lying between the Tropic of Cancer and the Arctic Circle or the Tropic of Capricorn and the Antarctic Circle and therefore rivers investigated in this essay will fall within these parameters. Rural catchments are slightly harder to define, as today very few large rivers do not have some form of urban development within their catchments area. In this essay a river that is still in a predominantly rural catchment will be discussed even if there are areas of urban land within the catchment. Humans impact on flood risk falls into one of two categories. The first is deliberately and directly, through floodplain restoration, construction of dams and channel rehabilitation and all of these have fairly obvious positive effects on reducing flood risk. However it is when humans indirectly affect the flood risk, through deforestation, land use change and climate change (which all have a negative effect on flood risk) that there is less certainty into the extent of the impact that humans have. Overall though it is clear that human activity has resulted in ‘major changes’ (Goudie, 2006) in downstream flood risk in temperate regions and rural catchments.
The most obvious way in which humans impact downstream flood risk is through direct adaptation of the river itself and this is also arguably also the most important way in which humans can have an impact on flood risk (Mrwoka, 1974). Damming is probably the most widespread example of how humans seek to control peak flows on rivers and the construction of dams in the UK has led to significant decreases in flooding. The reservoir created on the River Avon occupies 1.38% of the catchment but reduces peak flow by 16% and even more impressively the
Before we can evaluate human impacts on flood risk we must first establish what is meant by temperate regions and also rural catchments. Temperate regions are generally regarded as lying between the Tropic of Cancer and the Arctic Circle or the Tropic of Capricorn and the Antarctic Circle and therefore rivers investigated in this essay will fall within these parameters. Rural catchments are slightly harder to define, as today very few large rivers do not have some form of urban development within their catchments area. In this essay a river that is still in a predominantly rural catchment will be discussed even if there are areas of urban land within the catchment. Humans impact on flood risk falls into one of two categories. The first is deliberately and directly, through floodplain restoration, construction of dams and channel rehabilitation and all of these have fairly obvious positive effects on reducing flood risk. However it is when humans indirectly affect the flood risk, through deforestation, land use change and climate change (which all have a negative effect on flood risk) that there is less certainty into the extent of the impact that humans have. Overall though it is clear that human activity has resulted in ‘major changes’ (Goudie, 2006) in downstream flood risk in temperate regions and rural catchments.
The most obvious way in which humans impact downstream flood risk is through direct adaptation of the river itself and this is also arguably also the most important way in which humans can have an impact on flood risk (Mrwoka, 1974). Damming is probably the most widespread example of how humans seek to control peak flows on rivers and the construction of dams in the UK has led to significant decreases in flooding. The reservoir created on the River Avon occupies 1.38% of the catchment but reduces peak flow by 16% and even more impressively the
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