Groundwater Vulnerability Zones Mapping Using DRASTIC and GOD Methods in Krendowahono Village, Karanganyar Regency

Abstract

Krendowahono Village is located in Karanganyar Regency, Central Java, Indonesia. During the dry season, several hamlets in Krendowahono Village experience a shortage of clean water. So an attempt must be made to maintain the quality and protect groundwater sources in areas of Krendowahono Village with fresh groundwater supplies. Analysing the vulnerability of groundwater is one of the attempts that can be made. The DRASTIC and GOD methods were used to conduct a vulnerability analysis of groundwater. The DRASTIC and GOD vulnerability assessments were then validated using water samples taken from resident wells. Groundwater vulnerability assessment utilizing the DRASTIC method resulted in the identification of two vulnerability classes: low vulnerability and medium vulnerability. While the GOD method generates three vulnerability classes for groundwater, they are low vulnerability class, medium vulnerability class, and high vulnerability class. The maximum correlation value between the results of the GOD method and the test of water samples with parameters of free ammonia, total dissolved solids (TDS), and salinity was obtained when the results of the GOD method and the test of water samples were validated using Spearman’s correlation. The correlation value associated with the pH parameter was the highest in the DRASTIC method. Likewise, the GOD method produced favourable performance in regional studies. This is demonstrated by the significant correlation between the GOD susceptibility test findings and the water sample test results.