CS(AR)-25/98-99 : Spatial variability of groundwater quality in Jammu district (J&K)

Abstract

Management of groundwater is very important to meet the increasing demand of water for domestic, agricultural and industrial use. Groundwater quality deterioration is receiving increased attention, especially in densely populated regions. This has led to considerable interest in the design of investigative studies and monitoring programs to describe groundwater quality over various sizes of areas. Various management measures need to know the spatial and temporal behaviour of groundwater.

The spatial dependence between observations can be expressed by the semivariance 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..

In this report, an application of kriging technique is shown to quantify the spatial variability and to interpolate the groundwater quality as measured in part of Jammu District of J&K State. Experimental semivariogram were computed for nine groundwater quality variables and the theoretical models were fitted to each of these. Various groundwater quality variables (i.e. pH, potassium, magnesium, conductance, sodium, and chloride) were found to be spatially autocorreiated, whereas, variables such as alkalinity. calcium and hardness were found to be non-autocorrelated at the sampling scale. pH was found to be spatially autocorrelated upto a distance of 10km, magnesium, chloride and potassium upto a distance of 14km and conductance upto a distance of 34km. The semivariogram model obtained from the semivariance analysis was used to estimate observations in the unsampled locations within the area. The so obtained values were used for groundwater quality contour mapping.