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Professor Hamlin has been an independent water engineering consultant and has acted as an expert panel member on dam projects in Africa.
He was Vice Chancellor of Dundee University from 1987 to
1994.
He was born in South Africa and talked about his father’s philosophy which was that education was the greatest gift one could bestow and that one had a duty to provide for those unable to follow a normal route to higher education. The presentation would cover distribution, history, water borne disease and the future.
Water distribution
Everyone knows something about water. How much is there? In the world there is 1360 cu km 97.2% in the oceans, 2.5% in glaciers of which 90% is in Antarctica. 13,000 cu km is held in the atmosphere and 1300 cu
km is locked up in plants, surface and underground water. The circulation of this water is controlled by solar energy drawing water up into the atmosphere and then that falls as rain and if all this were precipitated simultaneously it would give about 25 mm. It is difficult to determine how the atmosphere is going to behave. About 600 mm falls annually on the earth’s surface, it is not known how much falls on the
sea. 10,000 mm a year falls on the Himalayas and next to nothing on the arid regions. In Botswana there was no rain for
five years and a decision taken to build a dam, it did not rain for a further 2 years but then in one year there was enough water to fill the dam. The behaviour of the cycle is very unpredictable. In the UK we average 670 mm a year, much of it in Scotland.
History: Primitive communities all live along perennial streams and their movement was controlled by the supply of water, the bush-men of the Kalahari being an exception. When the skill of well digging developed there was the possibility for movement over a wider area.. Other than water for drinking from about 4,500 BC man began to interrupt the cycle by digging contour drains in the Euphrates valley. The first reservoirs were built in Ceylon, 500 BC to
1 BC, these were large but not deep. They became a prosperous agricultural economy.
Working in Nigeria in the 1970s Professor Hamlin visited a clinic whose water supply was an open well that also received faeces from children, dogs etc. Diarrhoea was rife and the suggestion was to cap the well before spending more money on the clinic.
Water-borne diseases
In Ceylon the malaria mosquito appeared in the 13th century. Because the canals and dams were so well maintained the disease did not take a hold.
However with an invasion from India the canals and dams fell into disrepair, malaria escalated and the population of Ceylon fell from 20 million to 2 million.
Other water-borne diseases are bilharzia and schistosomosis. The later disease escalated in the Sudan with the building of irrigation schemes, over a period of 10 years 85
per cent of the population became infected. The Tennessee Valley scheme was the first to acknowledge that disease was spread through irrigation. A solution was to lower the level of the water, thus stranding the breeding grounds, and the insects could be killed with DDT. The banning of DDT in the west was not welcome, particularly as we do not suffer from malaria.
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In the UK cities started off using underground water and it was at the
'Broad St' pump in Mayfair that a man, John Snow, discovered the link between cholera and polluted water. This led to the first Public Health Act at the end of the 19th century resulting in the dramatic fall in the mortality rates. A further fall came with the introduction of antibiotics. As cities developed local supplies were no longer sufficient and the need for water became evident, Birmingham looked to Wales and the Elan Valley. These engineers were amazing with the tools at their disposal they built dams, aqueducts and tunnels and pipes which provided a fall of 1 foot per mile to get the water flowing steadily. Liverpool looked to Lake Vyrnwy and Manchester to the Lake District. Water flowing from the big conurbations became polluted, in London streams up-stream discharged into the Thames, lower down stream water was taken out, which people drank it and put it back in. It was the Water Resources Act in the 1960 to 70’s started the clean up. The new reservoirs are multipurpose, storage capacity is related to the availability of water to fill it, they could also be used in flood control because at the end of the summer water could be drawn down to take the winter rains. In Wales at Dinorwig two reservoirs have been built one on high land and one on low, at night the water is pumped up and during the day falls down generating electricity which is exported to the grid.
International Issues
The position overseas is very harsh with regard to water.
The magazine World Water in its editorial made the comment that if the money spent on arms in 15 days was diverted to the water projects the problem would be solved. Also if people stopped smoking for 3 months the result could be the same. Over the last decade many more people have been given water and better sanitation, but any benefit has been wiped out by population growth. The situation at an individual level was highlighted by a researcher in Swaziland. At the beginning of the planting season a women only gets 1,200 calories per day in food, after walking to collect water and doing her other jobs she has used up all but 200 calories to fuel her work in the fields. Weeding the maize crop is vital because it increases yield from 50 to 100%, a water pipe line would transform their lives. What can water engineers do to make the environment a better place, sustainable in the face of climate change. If we do nothing we condemn future generations, even if we cannot predict events that exacerbate the situation. We can do something but it needs human will. The issues are: better management of water; a multidiscipline approach and a multicultural exercise involving all kinds of groups. Many things are done without reference to third parties. Politicians need to consider all these problems. Hydrological control of water needs to be integrated; transportation of silt is important; land use both up and down stream needs to be co-ordinated as do the riparian economies. Hydro-meteorological information has to be collected and disseminated. In Turkey reservoirs were built on the Euphrates but countries downstream
were ignored. Costs and benefits need to be equitably distributed, now and across the generations minimising or avoiding irreversible effects.
Three million people have been displaced by the Three Gorges Dam and nothing has been done for them. A democratic and collective process for decision making and conflict resolution is essential, even if a dam is required for the
'good of the country’s' economy.
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