write the explain the types of wells
Answers
There are in fact three major categories of well : dug wells, driven wells and drilled wells, commonly known as boreholes.
Dug wells
Digging in the ground with a spade and a pickaxe is the most simple and oldest technique.
It is also the most tiring as well as the least costly. The soil has to be relatively soft and the water table fairly shallow. These wells are often edged in stone to reinforce them and prevent them from collapsing, but it is far better to case them (keep them vertical) with concrete rings often produced easily on site using moulds.
Less rustic mechanical digging resources can also be used to reduce the considerable physical effort.
Dug wells are not very deep (between 10 and 20 m usually, 30 to 40 m exceptionally). As they are fairly shallow, they risk being contaminated and can dry up more easily than the other types of well.
Driven wells
Driven wells are constructed by driving a small-diameter, perforated tube with a pointed end into friable ground like sand or gravel using a vertical to-and-fro movement (except for the special undercutting technique). A filter, or screen, is very often fixed to the lower section of the pipe to filter the sand and other particles and prevent them from penetrating into the well.
They can only draw the water from average depths of between 15 and 100 m depending on the technique used. Like the dug wells, they are also exposed, but less so, to contamination and drying up.
Drilled wells
A large number of modern wells are drilled, meaning that they are dug by percussion of a tool in the soil or by the rotary action of a cutting tool (augur, drill bit) revolving around a vertical axis. This breaks and chews the rocks, with the residues usually brought up to the surface by sludge.They can be up to 300 m deep.
Answer:
There are in fact three major categories of well : dug wells, driven wells and drilled wells, commonly known as boreholes.