Analysis of Soil Absorption Capacity of Rainwater in Biopori Infiltration Holes in Purwoyoso Village Semarang City

Abstract

Drought and floods that hit Semarang City were caused by problems with water distribution and capacity. The ongoing conversion of land functions in the city of Semarang has resulted in reduced green open space and increased building density. This resulted in reduced infiltration of rainwater so that surface water runoff increased. Thus, causing a flood disaster that hit the city of Semarang in 2022, in which 7 out of 16 sub-districts were affected. This condition is exacerbated when rainfall is high and causes stagnant water because the existing drainage system is not optimal. The application of biopore infiltration holes in an effort to expand the rainwater infiltration area is a form of defense that can be carried out by the people of Semarang City in minimizing the occurrence of floods and groundwater crises. This study aims to analyze the absorption capacity of soil against rainwater in biopori infiltration holes in Purwoyoso Village. The method used is the Constant Head and Falling Head tests. The results of the groundwater absorption test showed that in sample B.1. and B.2. are 8.976.E-05 cm/sec and 9.488.E-05 cm/sec respectively. These results indicate that the absorption capacity of the soil in the biopori infiltration holes for rainwater is low or lacking.