Explain how human factors (urbanisation, land-use change and
deforestation) can affect flood hydrographs.
Human factors increasing flood risk:
urbanisation, because towns and cities have more impermeable surfaces
deforestation, because removing trees reduces the amount of water intercepted and increases run-off
Explain how physical and human factors cause river flooding in the
Heavy localised rainfall,
Saturated ground from previous rainfall.
The lake district acted as a funnel directing vast volumes of water into the river Eden.
The drains in Carlisle were blocked because of the heavy rainfall.
The reservoirs in the lake district were already full - they couldn’t take any more water and so they overflowed.
What are the effects of flooding on people and environment? What
problems were caused?
As most people are well aware, the immediate impacts of flooding include loss of human life, damage to property, destruction of crops, loss of livestock, and deterioration of health conditions owing to waterborne diseases. As communication links and infrastructure such as power plants, roads and bridges are damaged and disrupted, some economic activities may come to a standstill, people are forced to leave their homes and normal life is disrupted.
Similarly, disruption to industry can lead to loss of livelihoods. Damage to infrastructure also causes long-term impacts, such as disruptions to supplies of clean water, wastewater treatment, electricity, transport, communication, education and health care. Loss of livelihoods, reduction in purchasing power and loss of land value in the floodplains can leave communities economically vulnerable.
Floods can also traumatise victims and their families for long periods of time. The loss of loved ones has deep impacts, especially on children. Displacement from one’s home, loss of property and disruption to business and social affairs can cause continuing stress. For some people the psychological impacts can be long lasting.