Groundwater Stability Assessment with Geospatial Modeling Using GIS: A Case Study of Illizi Town, Algeria

This paper presents a study of the influence of groundwater quality on supply network pipes in Illizi town, southeast of Algeria by assessing 5 parameters (pH, TDS, TH, TAC, and temperature) from 10 existent wells. All of the wells are used for drinking water supply from the lower Devonian layer. The influence of groundwater on the supply network was assessed by the calculation of Langelier stability index "LSI," Ryznar stability index "RSI," and aggressivity index "AI." The results show that all 10 samples are characterized by a under saturated waters. LSI ranged from -0.38 to -0.83, RSI range from 7.34 to 8.33 and AI range from 10.66 to 11.27 which means that the groundwater of the lower Devonian, theoretically, is moderately aggressive. The spatial distribution of Ryznar index was realized using ordinary kriging as a method of interpolation. The map shows that as we move to the ZHUN 103 well, the groundwater's under saturation increases, although the calculation classified the groundwater as moderately aggressive. But, the presence of iron ions and oxidation process in water plays an opposite role by scaling Fe3+ on interior surfaces of metallic accessories.