With reference to a river catchment that you have studied, assess the potential
factors which can impact upon the flood hydrograph.
Answer A
In examining the dynamics of flood hydrographs within the River Brock
catchment, several crucial factors come into play, each having a large
potential influence on the river's response to precipitation.
Firstly, the composition of the catchment's landscape, particularly the
presence of peat, significantly affects percolation rates and water
retention. Peatlands, characteristic of the catchment's upper reaches,
tend to impede rapid runoff by absorbing water, thereby delaying its
release into the river system which affects the hydrograph. However,
prolonged saturation can lead to diminished percolation capacity,
potentially exacerbating flood risks.
Secondly, human activities such as water abstraction, notably
exemplified by operations at Myerscough College, can disrupt the natural
hydrological balance. Intensive abstraction for agricultural or industrial
purposes reduces the volume of water available in the river system,
altering flow patterns and potentially exacerbating flood events by
diminishing the river's capacity to accommodate increased runoff.
Lastly, the urbanisation of areas like Bilsborrow within the catchment
introduces impermeable surfaces and artificial drainage systems,
amplifying surface runoff and accelerating the transfer of water into the
river network during rainfall events. The increase in the number of
impermeable surfaces slows infiltration rates, leading to rapid runoff
volumes, which can show on a flood hydrograph as steep rising limbs and
pronounced peaks.
In summary, the interplay of natural features, human interventions, and
urbanisation within the River Brock catchment collectively shapes its
flood hydrograph characteristics, highlighting the complicated nature of
flood risk management in river systems.
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factors which can impact upon the flood hydrograph.
Answer A
In examining the dynamics of flood hydrographs within the River Brock
catchment, several crucial factors come into play, each having a large
potential influence on the river's response to precipitation.
Firstly, the composition of the catchment's landscape, particularly the
presence of peat, significantly affects percolation rates and water
retention. Peatlands, characteristic of the catchment's upper reaches,
tend to impede rapid runoff by absorbing water, thereby delaying its
release into the river system which affects the hydrograph. However,
prolonged saturation can lead to diminished percolation capacity,
potentially exacerbating flood risks.
Secondly, human activities such as water abstraction, notably
exemplified by operations at Myerscough College, can disrupt the natural
hydrological balance. Intensive abstraction for agricultural or industrial
purposes reduces the volume of water available in the river system,
altering flow patterns and potentially exacerbating flood events by
diminishing the river's capacity to accommodate increased runoff.
Lastly, the urbanisation of areas like Bilsborrow within the catchment
introduces impermeable surfaces and artificial drainage systems,
amplifying surface runoff and accelerating the transfer of water into the
river network during rainfall events. The increase in the number of
impermeable surfaces slows infiltration rates, leading to rapid runoff
volumes, which can show on a flood hydrograph as steep rising limbs and
pronounced peaks.
In summary, the interplay of natural features, human interventions, and
urbanisation within the River Brock catchment collectively shapes its
flood hydrograph characteristics, highlighting the complicated nature of
flood risk management in river systems.
My score Actual score:
Examiner feedback:
