The different methods available for measuring water in open channels may be grouped as: 1. Velocity-area methods, and 2. Direct discharge methods. 1. Velocity-Area Methods: In these methods the velocity of flow in the channel is measured by some means and the discharge is calculated from the velocity and the area of cross-section by using Q=AV. The common methods for [...]
Several methods are available for measuring flow in pipes. Only a few of them which can be used on the farm are discussed here: 1. Volumetric Measurements: Flow measurements by this method are made by measuring the time required for the flow to fill a container of known volume. Volume divided by time is equal to the rate of flow. [...]
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 [...]
The capacity of a storage reservoir is determined on the basis of the inflow to the reservoir and the demand of the consumers (or the yield of the reservoir). The following two methods are generally used for determining the capacity of a storage reservoir: 1. Analytical Method: In this method an analysis of demand and inflow of water per month [...]
The analysis of water involves the various tests to be carried out for determining the impurities which may be present in water. The following three types of analyses are carried out for water: (1) Physical Analysis: The physical analysis of water involves the physical tests which are carried out to determine the physical impurities and the corresponding physical characteristics of [...]
The commonly used turbidimeters are as indicated below: 1. Jackson Turbidimeter (or Jackson Candle Turbidimeter): It consists of a graduated glass rube placed in a metal cylindrical container which is supported on a metal stand. At the bottom of the stand a standard candle of bees wax is fixed. The candle is so designed that it burns within the limits [...]
For detecting the presence of bacteria of coliform group and measuring their concentration in water the following methods are adopted: I. Total Count or Agar Plate Count Test: In this lest, bacteria are cultivated on specially prepared medium of agar for different dilutions of sample of water with sterilised/distilled water. The dilutions commonly used are 1/10, 1/100 etc. The diluted [...]
In this article we will discuss about:- 1. Mechanism of Precipitation 2. Types of Precipitation 3. Measurement 4. Average Annual Rainfall, Maximum and Minimum Annual Rainfall. Mechanism of Precipitation: Water vapour from which precipitation is derived is present in the atmosphere as a gas in varying amount at all times. The absolute amount of vapour in the air depends upon [...]
In this article we will discuss about how to remove colour, odour and taste from water. Aeration: Aeration is a process in which water is brought in intimate contact with atmospheric air to promote exchange of gases between water and atmospheric air. The aeration of water serves the following purposes: (i) In the course of aeration, oxygen from atmospheric air [...]