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RAJIV GANDHI NATIONAL DRINKING WATER MISSION (RGNDWM)

PHASE III AND GROUND WATER QUALITY MAPPING PHASE IV

A. Introduction
MRSAC, Nagpur in collaboration with Groundwater Survey and Development
Agency (GSDA), Pune & National Remote Sensing Centre (NRSC), ISRO / Dept. of
Space, Govt. of India, is preparing ground water prospects maps using remote sensing
and GIS technology under Rajiv Gandhi National Drinking Water Mission (RGNDWM)
project. The project is sponsored by Department of Drinking Water Supply (DDWS),
Ministry of Rural Development (MoRD). The ground water prospects maps have already
been prepared for the Maharashtra state. The ground water prospects maps provide
information on a) potential zones for the occurrence of ground water and b) site-specific
recharge structures.
General information on the ground water quality in terms of its potability and
elements that are making the ground water non-potable, in case if the water is non-
potable, are also being provided in the ground water prospects maps. The ground water
quality information, as given in ground water prospects map is based on the well
observation in the field / data collected through enquiry from the local people, not based
on the analysis of ground water samples.

B. Objective
Mapping of the quality of ground water, particularly, using legacy data is a
technically challenging task. There are many factors that govern the quality of the water
and its distribution in space and time. Availability of data pertaining to all the governing
parameters is also a major issue. In most of the cases, the spatial distribution of the
quality of ground water has been depicted in terms of the locations of the wells having
quality problem with respect to different elements. Ground water quality map showing the
spatial distribution of the quality of ground water is the main output to be delivered in the
project. It is to be in the form of an additional map corresponding to Survey of India
toposheet on 1:50,000 scale. The ground water quality information is to be generated by
considering eight common elements – Ph, Alkalinity, Hardness, Chloride, Fluoride, Iron,
Nitrate, Phosphate – as a mandate and remaining 25 elements depending on the
availability of the ground water quality data in the input legacy data. The unit for depicting
the quality of the ground water should be in terms of its suitability for human consumption
i.e. 1) potable, 2) Permissible and 3) Non-potable as per Bureau of Indian Standards
(BIS).

C. Methodology
The entire process of ground water quality mapping can be broadly divided in to
three major parts. In the first part, the input data required for generating the ground water
quality map is to be processed and to be organized into a GIS data base. In the second
part element-wise ground water quality layers are to be created from the GIS data base.
And in the third part, the final ground water quality map is to be derived based on the
integration of the element-wise ground water quality layers.

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MRSAC,Nagpur ©®
MRSAC,Nagpur ©®