KESEIMBANGAN MASSA PADA SISTEM PANAS BUMI BERDASARKAN DATA HIDROGEOLOGI DAERAH PROSPEK GEDONGSONGO KOMPLEKS GUNUNGAPI UNGARAN KABUPATEN SEMARANG PROVINSI JAWA TENGAH

Abstract

The research area is located about 30 km southwest of the city of Semarang, precisely in the
Volcano Complex Ungaran Semarang regency, Central Java province. Gedongsongo, Kaliulo,
and Kendalisodo, is one of the areas that indicate a geothermal potential is characterized by the
presence of some symptoms of geothermal surface manifestations.The principle of mass balance
(mass balance) is entering (water) comparable to those lost to the surface (heat). In the
geothermal system, the stability of the production of steam to be generated is determined by the
balance between water recharge and discharge. Thus it needs to know how big the incoming water
(infiltration of precipitation) and how hot out (heat loss) in the system. Hydrogeology is closely
related to heat loss and potential recharge in the determination of the mass balance in the
geothermal system that took place in the area of research. Parameters related to the potential of
recharge is vast recharge area, slope and rainfall are affecting the recharge area. Based on
calculations, the greater these parameters, the greater the potential recharge. Based on the results
of the calculation of the amount of rainfall in Ungaran is equal to 711 mm / month or 966 liters /
second / km while recharging the greatest potential in the amount of 23017.28 ltr / sec contained
in zone 2 with an area of 572 km², there is the area of influence of rainfall rain station 1 (station
Ungaran-SMG 30) with a slope of 135.52%.