Groundwater

The study presents a status report on hydrological problems of hard rock areas related to hydrological network design, groundwater quality, failure of open and borewells, regional flood formulae, groundwater balance studies, reservoir sedimentation, hydrological aspects of droughts, forest hydrology and drainage problems of black soil of the hard rock terrain.

The report tries to review the hydrological studies done in the northeastern region of India by all agencies, governmental or non-governmental. Sufficient care has been taken to include all the salient features of the studies to make it comprehensive. The various information  included in this report are the purpose and year of study, location and extent of the study area with its brief description, data used, list of specific studies along with its results and recommendations wherever possible.

An attempt has been made to pull together all the studies related to hydrology and its allied field. Besides these planned studies done by various departments, research studies done by academic institutions and research and development organizations has also been included.

Organizer: National Institute of Hydrology

Topics:

• Need for Hydrological Investigations
• Conventional Techniques and methods for Hydrological Investigations;
• Application of Remote Sensing and GIS
• Application of isotopic techniques in surface water and groundwater investigations;
• Advance techniques for measurement of soil erosion and reservoir sedimentation
• Advance instrumentation for hydrological investigations; and
• Advance computing techniques for hydrological data analysis.

The study evaluates groundwater on the basis of widely used graphical methods like Piper, Stiff and US Salinity Laboratory classification. The study concludes that, in general, the groundwater in the area varies from medium salinity to very high salinity, the latter being more common in the irrigated stretches. The irrigators are advised to ensure good land and water management practices in the fields, with particular emphasis on creating favorable leaching and drainage conditions to avoid further development of saline conditions in the area. 

The study applies geostatistical techniques to the groundwater quality data of December 1994 in parts of Jammu district. Groundwater quality deterioration has led to considerable interest in the design of investigative studies and monitoring programs on the issue.

Various management measures need to take into account the spatial and temporal behavior of groundwater. The spatial dependence between observations can be expressed by semi variance, which is a measure of the average similarity between observations at a given distance apart. One of the prime reasons for obtaining a semivariogram is to use it for estimation of the variable at unsampled locations.

The study applies a simple five-parameter model based on the concept of probability distributed method as proposed by Moore (1985) to simulate the daily runoff over a nine-year period of 1989-1997 at Tamavaram in Prakasham district of Andhra Pradesh on the Gundlakamma river.

Groundwater models simulate groundwater flow in sub-surface aquifers in terms of quantity (level) and quality (such as salinity) using the mathematical or numerical approach. When a Groundwater model is embedded in a management framework these are often referred as managment models.

The study presents the spatial analysis of groundwater levels and its quality for the year 1998 for Kakinada town in coastal Andhra Pradesh. The Deltaic Regional Centre of NIH has been monitoring groundwater levels and its quality in and around Kakinada town since 1994. Groundwater samples have been analyzed for physical and chemical parameters. The variation in each parameter is discussed in the report.

A total of 164 samples were collected from 41 observation wells during the months of February, May, August and November 1998. The area covered by these observation wells is around 82 sqkms. The groundwater table contours were plotted for pre-monsoon (May 98) and post monsoon (November 98) periods and the approximate flow direction had been demarcated.

The study attempts to determine the water quality of all available sources of water be it surface, ground or waste water and find out the likely sources of pollution for the Hardwar district of Uttar Pradesh. The physico-chemical parameters of the water were determined. The effect of monsoon on the water quality was studied by collecting and analyzing the pre and post monsoon samples.

The study on groundwater quality of Greater Guwahati analyses various trace elements in samples and ascertains that their concentration is much higher than the tolerance limit prescribed for drinking water. The trace element analysis focuses on metals such as Cu, Co, Cd, Fe, Zn and Pb.

Owing to the inadequacies of piped water supply, the Greater Guwahati area depends on groundwater from ringwells and tubewells for drinking purposes. Groundwater is mostly polluted from the effluents discharged by industries on land, seepage from sewage lines & tanks and application of pesticides on agricultural land. Due to the low flow velocity, groundwater once contaminated will remain so for longer periods. Metals assume significance because of their greater toxicity, accumulative and non-biodegradable behavior.