GIS BASED INFORMATION MODEL FOR ASSESSMENT OF GEOTHERMAL POTENTIAL: CASE STUDY OF TENGCHONG COUNTY, SOUTHWEST CHINA

An accurate assessment model for geothermal potential regions can help to lower the risk of the development and to reduce the investment. Based on the platforms of GIS, the promising geothermal areas are identified through the information value model according to the relationship between geothermal occurrences and their controlling factors in Tengchong county, China. Publicly available databases for this analysis include epicenters, distribution of faults, Bouguer gravity, Landsat7 Enhanced Thematic Mapper Plus(ETM+)images, the magnetic data, and digital elevation model(DEM)data. They are extracted as the b-value map, distance to faults map, distance to main grabens map, LST(land surface temperature) map, magnetic anomaly map, and distance to rivers map respectively. To ensure the model is suitable to evaluate the geothermal potential sites within the region, the method of factor analysis based on information values is applied to test the conditional independence. The results of index analysis and area ratio analysis indicate that the information value model can be applied well in the evaluation of geothermal potential regions. Four potential areas in final map, of which have not been explored or exploited, are located in Longchuan River, Nandi River and Nu River. Furthermore, the total area of unexplored geothermal potential field is 1835.6 km², accounting for 6.72% of study area. It is expected that the study can guide further preliminary investigations performed for large areas having limited information and can lower the risk in economy.