In this article we will discuss about the artesian wells and calculation of its yield.
Artesian Wells:
This is the name derived for the well from which water flows automatically under pressure. The water from these wells flows out in form of foundation to a height of 2.5 metres depending on the hydrostatic pressure. In some artesian-wells water flows continuously throughout the year and can be stored in tanks for water supply purposes, which may vary from 4,500 litres to 1,14,000 litres.
The given figure 4.23 shows the geological conditions of the earth under which such wells are formed. Mostly these are found in the valley portion of hills, where confined stratum aquifers on both wide are inclined towards the valley. The hydraulic gradient line passes much above the mouth of the well, due to which hydrostatic pressure is increased causing the flow of the water under its pressure.
Yield of an Artesian Well:
Refer to Fig. 4.24 of an artesian well.
Let H = Depth of water before pumping
h = Depth of water during pumping
At = Thickness of the aquifer below the impervious stratum up to which well is constructed.
ADVERTISEMENTS:
R = Radius of the circle of influence
r = Radius of the well
J = Any point of the drawdown curve having its co-ordinates as x and y with respect to the origin being at the centre of the bottom of the well.
As the yield of the wells is:
