Spatial Analysis of Groundwater Hardness, Electrical Conductivity, pH, and Underlying Causes for Variations in Ratnapura District, Sri Lanka

Abstract

Hardness in drinking water may not be harmful to human health, though it can cause a variety of problems at both the domestic and industrial levels, most notably its objectionable taste and scale deposition. Excessive hardness in groundwater of the Ratnapura district has been perceived, particularly in the district’s dry and intermediate zones. Despite the fact that many residents rely on groundwater for their daily needs, no previous groundwater hardness investigation has been conducted in the area. In this context, this research aims to analyze the spatial distribution of groundwater hardness as well as pH and electrical conductivity (EC), including possible underlying causes. Georeferencing and spatial interpolation techniques were used to visually analyze the spatial variation of these three parameters over the area. Results revealed contrasting differences in all three parameters in the wet zone of the district compared with the dry and intermediate zones as well as alarming ranges of parameter values that exceed the standard limits for drinking water. Further, the study reveals that both climate conditions and geological conditions play a vital role in deciding the constituents of groundwater.