Classnotes: 8th December: Issues with water supply / Flood hydrographs

Issues with water supply - what problems are there because of a lack of clean water? How can these problems be solved?

Small scale aid projects
Aid = help provided by one group of people to another. Most international aid is given by MEDCs like France, Germany and the UK to LEDCs such as countries in Africa like Ghana and Mozambique.
Small scale = rather than giving huge amounts of money for a big dam, or a large power station, smaller amounts of money are given to local communities within the country - WaterAid is a great example of this.

Some key definitions
Labour intensive = requires a lot of people to work it i.e. gives lots of people jobs
Capital intensive = input of lots of money and probably uses advanced technology#
Intermediate technology = technology that local people in LEDCs can use and maintain - for example a small solar powered electricity generator rather than a large battery that runs out
Non-governmental organisations = usually charities that give aid to LEDCs such as Oxfam, WaterAid, Save the Children and so on (we didn't get on to this one - make sure you write it down somewhere)

WaterAid in Nepal
WaterAid is a charity doing work in the hills of Nepal to prevent disease spreading.
The charity gives money and tools to local people and encourages them to have a holistic (wider) view of the issue of water supply. They not only give access to clean water but also to clean ways to dispose of human waste - which otherwise would cause disease.


Flood hydrographs
There are two main types of graph - river regimes, which show the water levels in the river over a long period of time (months or years). Also, there are flood hydrographs which are used to show the water level of a river in relation to a precipitation event (a storm or period of rainfall). A really good summary of the graphs can be found here from BBC Bitesize.
There are several things that lead to a longer lag time:
Flat land (the water doesn't flow quickly to the river)
Unsaturated ground (ground that contains some water but not too much)
Soil
Rural areas (countryside)

Things that make a shorter lag time are:
Steep slopes
Very dry ground (think of a summer day when the ground is very hard - it doesn't soak water in very quickly)
Saturated ground (the ground is soaked through and can't get any more water)
Rocky ground
Urban areas (towns and cities)

These things can be split into two mains types:
PERMEABLE - surfaces which allow water to soak in
IMPERMEABLE - surfaces which don't allow water to soak in