A revised method for heat flux measurement with applications to the fracture-controlled Kangding geothermal system in the Eastern Himalayan Syntaxis

Abstract

Abstract A revised heat flux method to evaluate heat loss of a fracture-controlled geothermal system is presented, which includes updated field and lab procedures. The method is applied to the heat discharge study on two geothermal areas of the Kangding geothermal system in the western Sichuan plateau, namely the 0.32\u2009km2 Yulingong Thermal Area (YLGTA) and the 0.87\u2009km2 Zhonggu Thermal Area (ZGTA). Conductive heat flux is evaluated based on soil temperature measurements in the field at roughly 500 points and soil thermal conductivity measurements in the laboratory which amounts to 7.6\u2009±\u20090.2\u2009MW and 10.5\u2009±\u20090.2\u2009MW in the YLGTA and ZGTA, respectively. Convective heat released from soils amounts to 1.5\u2009±\u20090.5\u2009MW and 0.5\u2009±\u20090.1\u2009MW in the YLGTA and ZGTA, respectively. Heat released from hot springs is valued at 5.4\u2009±\u20091.1\u2009MW and 0.9\u2009±\u20090.2\u2009MW in the YLGTA and ZGTA, respectively. Total heat release from these estimates results of 14.5\u2009±\u20091.1\u2009MW and 11.9\u2009±\u20090.2\u2009MW in the YLGTA and ZGTA, respectively. The average heat fluxes of the YLGTA (45\u2009±\u20093\u2009W\u2009m−2) and the ZGTA (14\u2009±\u20091\u2009W\u2009m−2) are consistent with results found at many other volcanic-hydrothermal areas suggesting that geothermal system in compressive tectonic background without volcanic activity may have high thermal energy to be exploited.