Introduction to Basic Pollution Parameters:
Morphometry & General Information
1. Location:
The location of sampling station is an important factor. The latitude and longitude of the place be given.
2. History & Geology:
ADVERTISEMENTS:
The history of the area, formation of basin, land use of surroundings, soil condition etc. is to be mentioned. The data can be given from geological survey of India.
3. Bathymetric map (contour map):
It is prepared by recording depth at different points of equidistance in the pond or river. The number at points depends upon the size of the water body.
4. Depth:
It gives the idea of the amount of water present in the water body. It is defined as minimum vertical distance between surface and underlying bottom of pond or river at any point.
Requirement & Method:
Secchi disc with rope.
i. Lower the disc in water till it reaches the bottom.
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ii. Measure length of rope with the help of measuring tape in meter (m)
5. Maximum length (I):
It is defined as the distance between two far distant points on the surface of the water body (Land distance should not be measured).
6. Volume (v):
The volume is calculated with the help of the following formula.
V = h/3 (A1 + A2 + √A1A2)
ADVERTISEMENTS:
where V = Volume
h = Vertical depth
A1 = Area of upper surface of water body.
A2 = Area of lower surface of water body.
7. Mean depth (Z):
ADVERTISEMENTS:
It can be calculated by dividing volume of water body by its surface area.
8. Catchment Area:
It is defined as the surrounding area of water body which influences it indirectly or directly. It includes information on land use, geology, agricultural pattern and topography of the place.
Meteorological Observations of Basic Pollution Parameters:
1. Light:
Light intensity is measured by photometer. This parameter depends on the conditions whether at the time of experiment the light was dim, bright or full sun shine.
2. Wind:
The direction of the wind, its speed etc. are important factors to be noted at the time of the experiment. The terms used for wind speed are given in Table 1.
3. Cloud:
The amount of cloud is measured in Okta Units. It defines the deviation of solar radiation over a particular area.
4. Air Temperature:
Temperature is an index of heat. Air temperature is recorded avoiding direct exposure of mercury bulb to sunlight.
Six’s maximum—minimum thermometer is used to measure the air temperature.
5. Evaporation:
The water losses to atmosphere with per square meter are calculated. It is measured by using cylinders with and without macrophytic communities and observing the changes in the volume of water in cylinder after 24 hours with the help of the following formula.
L = V × 100/S × 1/N
where L = Loss of water
V = Volume of water lost (ml)
S = Surface area of container
N = Number of days of incubation.
6. Precipitation:
The heavy rains, showers or intermittent rains etc. are to be recorded in standard Rain gauge with watch at the time of performing the experiment.