Pattern and direction of groundwater flow and distribution of physical-chemical properties of groundwater in Randublatung basin

Abstract

The people in the Randublatung basin (Grobogan, Blora, and Bojonegoro Regencies) using groundwater for daily needs and agriculture activity. As the initial step of basin-based groundwater management, it is necessary to understand the groundwater potential in this area: pattern and direction of groundwater flow and groundwater physical-chemical properties (pH, temperature, total dissolved solids, and electrical conductivity). This research aims to analyze the pattern and directions of groundwater flow, the physical-chemical properties, and the correlation between the two. This research method is field measurement of 45 different spots of dug wells in the Randublatung basin. Our results indicate that the pattern and direction of groundwater flow in the Randublatung basin are heading to Bengawan Solo River and then following the river’s flow. The groundwater physical-chemical properties measured: pH value is 6.8 on average, the temperature is 28.9 °C on average, TDS concentration is 409 mg/L average, and electrical conductivity rate is 843 μS/cm average. There is no significant correlation between groundwater flow with pH value and groundwater temperature. However, groundwater TDS concentration and electrical conductivity rate in the Randublatung basin increase as groundwater flows to the Bengawan Solo River, which is affected by the minerals of aquifer rocks (alluvial deposits).