Study on Infiltration Capacity at Disaster-Prone Areas in Krasak's Watershed of Mount Merapi, Indonesia

In 2010, Mount Merapi erupted with over 140 million m(3) of pyroclastic materials spread across the nearby rivers. Those volcanic materials affect soil infiltration capacity. This implies that research related to infiltration rate of soils needs to be conducted. The present study aims to determine the values of soil moisture content, soil density, and the rate of soil infiltration capacity in the disaster-prone areas in Krasak watershed. In the research methodology, soil density inspection in the field had been conducted by using sand cone test method, soil sampling used a cylindrical vessel of diameter 10 cm and height 30 cm, and double-ring infiltrometer was used to measure the rate of water infiltration. There were three different locations for testing points, namely KIM I, KRB II, and KRB III. The results of this study show that the values of soil moisture content are 35.7 % in KRB I, 24.4 % in KRB II, and 17.8 % in KRB III. For the values of soil density, there are 10.454 KN/m(3), 11.69 KN/m(3), and 13.86 KN/1113 in KRB I, KRB II, and KRB HI, respectively. The rates of soil infiltration capacity are 42.638 cm/hour in KRB 1, 22.504 cm/hour in KRB 11, and 19.667 cm/hour in KRB III.