| Title | MONITORING AND QUANTIFYING HEAT LOSS FROM SIGNIFICANT GEOTHERMAL AREAS VIA REMOTE SENSING |
|---|---|
| Authors | C. Bromley, S. Ashraf, A. Seward, R. Reeves |
| Year | 2015 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | monitoring, heat-loss, satellite remote-sensing, thermal infra-red, calorimeter, Karapiti. |
| Abstract | Accurate assessment of natural heat loss from significant geothermal areas is essential for providing data to improve reservoir simulation and model calibration. Uncertainty in this parameter can lead to large uncertainty in resource assessments and in predictions of sustainable utilisation rates. Monitoring of surface heat-loss changes during production is equally important for history-matching of reservoir models and for assessment of environmental effects. New methods are under development for making better use of thermal infrared imagery from the newly launched Landsat-8 satellite, which has improved in quality and frequency (in tandem with Landsat-7). Along with ground-truth measurements, and high-resolution air-borne infrared surveys, these data are expected to achieve a longterm improvement in the determination of natural and induced changes in surface heat loss. Issues currently being addressed to assist with better heat flux estimates using remote sensing techniques include: accounting for surface emissivity variations and ambient (background) solar radiation; calibration against surface temperatures of water-bodies; and using optimized algorithms for atmospheric correction (split or mono window). With respect to heat-loss assessment, issues include: accounting for convective vapour loss; and dealing with spatial resolution issues. Integration of imagery with spot measurements of total heat-flux from areas of weakly steaming ground is challenging. This paper summarizes efforts to date in resolving these issues, and provides some examples of heat-loss assessments from Karapiti thermal area (Craters of the Moon), Wairakei, New Zealand |