The important methods that are available for drilling tubewells are as follows: 1. Percussion Drilling (Also Known as Cable Tool Method), further classified as: (i) Hand boring by rope or rod, and (ii) Mechanical boring with power rigs. 2. Rotary Drilling, further classified as: (i) Direct circulation hydraulic rotary, (ii) Reverse circulation hydraulic rotary, and (iii) Rotary-air percussion drilling. 3. [...]
Everything you need to learn about designing and constructing tubewells. Design of Wells: The design of a tubewell includes decision on: 1. Location of the well, 2. Type of well, 3. Method of construction, 4. Selection of the strata to be screened, length, diameter and material of the screen in case of strainer wells, 5. Diameter, size of slots and [...]
Groundwater management involves the planning and operation of the groundwater resources to provide safe and reliable water supplies. In groundwater management the factors that need to be considered include aquifer yield, recharge, water quality, socioeconomic and legal factors. Groundwater Basins and Safe Yield: The occurrence and movement of groundwater is confined to independent hydrologic units known as groundwater basins. Groundwater [...]
Water lifting devices are used both in irrigation and drainage. When the sources of irrigation is at a higher level than the field to be irrigated (e.g. reservoirs) water flows by gravity to the field to be irrigated. This is known as flow irrigation. When the source is at a lower level than the area to be irrigated, the water [...]
In this article we will discuss about:- 1. Total Head in a Centrifugal Pump Installation 2. Net Positive Suction Head 3. Power Requirements of Pumping 4. Selection of Centrifugal Pumps 5. Specific Speed of Centrifugal Pumps 6. Affinity Laws 7. Installation of Centrifugal Pumps 8. Operation of Centrifugal Pumps 9. Common Troubles of Centrifugal Pumps Installation. Contents: Total Head in [...]
In this article we will discuss about interference among wells and flow in a well. Interference among Wells: If two or more wells are located so close to each other that when they are discharging their drawdown curves intersect then one well is said to interfere with the other. Observations indicate that due to the interference of wells the discharge [...]
In this article we will discuss about well shrouding and well development. Well Shrouding: The shrouding is a layer of coarse material such as gravel and coarse sand interposed in the annular space between the well pipe and the aquifer soil. The shrouding prevents the finer particles of the soil coming in contact with the strainer and choking it, acts [...]
In this article we will discuss about how to construct tube wells. Construction of Shallow Tube Wells: Shallow tube wells are constructed by boring, driving and jetting. The wells constructed by these methods are designated as bored wells, driven wells and jetted wells. These methods are briefly described below: (i) Bored Wells: Where, water table exists at a shallow depth [...]
The yield of an open well can be found by the following two practical methods or yield tests: 1. Constant Level Pumping Test 2. Recuperation Test. 1. Constant Level Pumping Test: In this test water is pumped from the open well so that the water level in the well is depressed by an amount h known as depression head (or [...]
In this article we will discuss about the types and hydraulic properties of aquifers. Types of Aquifers: Aquifers are mainly of two types as indicated below: 1. Unconfined Aquifer: An unconfined aquifer is the one in which water table forms the upper surface of the zone of saturation. It is also known as water table aquifer; or phreatic aquifer; or [...]