Abstract: This research has been conducted in the geothermal manifestation area in Pablengan Kaliulo, Semarang Regency, Central Java. existing research describes the lithology and faults in the Pablengan Kaliulo geothermal manifestation area. Previous research has not described the characterization of hot springs in the geothermal manifestation. This study uses the HVSR method with data processing using geopsy software then converted using dinver and made 3D modeling using rockworks software. The results of this study indicate that the hot spring relased to the surface through a point where it has high porosity. Based on Vs data, the areas where the fluid flows are sand and sandstone.

Abstract: The physical study of changes in flow mass along the Ranoyapo river estuary can be based on position and time distributions for physical variables of flow density. Analysis of this variable and its changes along the river estuary can show the process of erosion or sedimentation that occurs in the estuary area. Data availability and physical variable profile of mass flow density produce function and rating curve of variable changes in flow density along the Ranoyapo river estuary at low tide and tide, which can then be useful to evaluate the process of transport material distribution which includes bed load, suspended load, and wash load along the river estuary. The analysis includes, (1) data multiplication techniques, (2) data modeling techniques for determining the rating curve for flow density variables. For modeling purposes, data is duplicated using linear interpolation techniques. The modeling of river flow mass yields the function and rating curve of changes in river flow mass density along the Ranoyapo Amurang estuary. Interpretation of the function, rating curves ρ0, and ρ0,6h during low tide and high tide indicate that during low tide, there has been a deposition of the baseload, with a large proportion (decrease in gradient ρ0which is quite large), while the deposition of the load rinse and baseload is relatively small (gradient ρ0,6h close to zero). At high tide, the baseload deposition in the estuary area increases, and the accumulation area shifts upstream following an increase in sea level. At high tide, the deposition of rinse loads and drift loads also increase, and the deposition area also expands due to shifting the position of the two function boundaries upstream, following sea-level rise. If the seawater moves back down, the sedimentation of the baseload, the drift load, and the wash load decreased.