Groundwater is one of the most important natural resources required for
domestic, irrigation and industrial purposes. It can be optimally used and sustained only if
the quantity and quality of groundwater are assessed with a reasonable degree of
accuracy. It has been observed that lack of a simple method of groundwater estimation leads
to mishandling of the resource. It is vividly clear that overexploitation of groundwater
leads to deterioration of groundwater quality, which makes the water unfit for
domestic, irrigation and industrial purposes. The paper presents the method of estimation
of groundwater quantity and correlation of the quantity and quality of groundwater
with various parameters using Geographic Information System (GIS).
Narasimha Prasad (2003) carried out a study on the pattern of water level fluctuations,
hydrogeological properties of the rocks and groundwater assessment, using parameters
such as drainage, base flow and rainfall. Ashok Kumar et al. (1999) analyzed
the fluctuations in the water level using Digital Basement Terrain Model (DBTM).
The study indicated that remotely sensed lineaments are important for groundwater
exploration and it can be ascertained using DBTM. Ashok Kumar and Savita (1998)
assessed the groundwater resources, using hydrogeomorphological and geophysical
surveys. Hydrogeomorphological units were delineated using images and the layer
resistivity was analyzed using the electrical resistivity method. Asadi et
al. (2005) undertook a study to assess the groundwater quality to demonstrate
its spatial distribution and to correlate it with the land use pattern. They
calculated the water quality index to assess the suitability of water for drinking
purpose. In this article, a method to estimate the quantity of groundwater and
to correlate the quality of groundwater with recharge has been presented.
Coimbatore district is one of the largest districts of Tamil Nadu and is situated
in the western part of the state. The district has an aerial extent of 7470
sq.km, accounting for 5.74% of the total geographical area of Tamil Nadu. The
district lies between the latitudes 10°13¢00²N to 11°23¢
30²N and the longitudes 76°39¢00²E to 77°30¢00²E.
The district has a length of about 130 km from north to south with an average
width of 70 km. For administrative purposes, this district has been divided
into 9 revenue taluks and 19 blocks. In most parts of the district, the
groundwater quality is moderate and the value of the Total Dissolved Solids
(TDS) varies between 500 and 2000 mg/L. The TDS values of samples taken from
the taluks of Avinashi, Palladam, Mettupalayam, Pollachi and Udumalpet are found
to be suitable for irrigation purpose. Good quality of groundwater with TDS
value less than 500 mg/L occurs in some parts of Pollachi and Palladam taluks.
However, high salinity with TDS value above 2000 mg/L is also observed in some
parts of Pollachi and Udumalpet. Around Palladam and Udumalpet, the quality
is poor due to the presence of black cotton soil and poor drainage. |
