A Study On Land Surface Temperature Retrieval And The Geothermal Distribution Characteristics In Changbai Mountains

Changbai Mountains with a dense forest cover and typical volcanic physiognomy lie the southeast of Jilin Province, China. Changbaishan volcano is the largest composite volcano in China. The activity of Cenozoic volcano is intense in this region. There are good conditions for the forming of the terrestrial heat and nicer future for the exploitation.Land surface temperature is an objective parameter of thermal infrared remote sensing retrieval. It is very important to obtain land surface temperature for the studies of energy balance between earth and atmosphere and ecology. Land surface temperature comes from two ways, one is the sun's radiance and the other is deep heat source's heating inner the earth. The energy transfer of the deep heat source inner the earth takes place by heat exchange or convection, which is commonly affected by the physical chemistry characters of geologic body and geological structure. This energy transfer can cause the increasing of local surface temperature. It is an important gist for geothermal detection if this transfer forms temperature abnormal. The paper applies temperature and emissivity separation (TES) algorithm to Changbai Mountains for land surface temperature retrieval based on the characters of ASTER data firstly, and analyzes land surface temperature, geological structure and the data of the hot water and the deep gas of the study area for studying geothermal resource's distributing in the region. The mainly job is the land surface temperature retrieval and the geothermal resource's distributing as follow:We obtain land surface temperature of Changbai Mountains using TIR image from ASTER by the reference channel emissivity (RCE) algorithm and compound TES algorithm. We select Band 13 as a reference channel when we retrieve the land surface temperature using RCE algorithm because the Band 13 is mostly close to real land surface. For Compound TES algorithm, it use normalized emissivity method (NEM) to estimate initial emissivity value for each band, and ratio algorithm (RAT) to compute the ratio of the channel emissivity to the average of the whole emissivity, and maximum minimum difference (MMD) to correct the emissivity, and Plank law to compute land surface temperature, and temperature to recomputed the emissivity for each band, and return the NEM till the error for the neighbor temperature satisfy the require. The result indicates that the both algorithm can quickly obtain land surface temperature only rely on ASTER data. The land surface temperature weobtain is closed to the observation data for weather station, so it can satisfy the geothermal resource study. The compound TES algorithm based on NEM, RAT and MMD and mended single TES, so the precision is higher than RCE. The land surface temperature retrieval result suggests that the high temperature area is covered by resident land, bare land, ginseng plastic canopy and road, and the low temperature area is covered by water and density forest. The temperature distributing is accord with the common rule. Wangtie'e is an area which the low temperature collected in the whole region, but Changbaishan Tianchi volcano entourage we consider as a temperature abnormal area collected by the high temperature. There are a larger number of magma mixing bared on the southern and eastern of the temperature abnormal area which the abnormal temperature mainly caused by sun radiance, but it is correlated to the terrestrial heat activity on the northern and western area.We interpret geological structure according to enhance the visual and near infrared RGB image. Five linear faults (that is Liudaogou- Changbaishan Tianchi-Zheng'oufenshan NE fault, Bapandao- Erdaogang NE fault, Manjiang-Baishan NWW fault, Songshan-Tianchi NWW fault and Tianchi-Hongtoushan NNW fault) and five ring faults (that is four ring faults around Changbaishan Tianchi and one ring fault in Wangtian'e volcano) are interpreted in this research. The fault is mainly NW, NE and nearly EW in the study area. The interpreting conclusion is accordant with the truth.Setting the east and north of the temperature abnormal area around Changbaishan volcano for objective area, we analyzed linear and ring faults, thermal springs, temperature and depth of the deep gas from the earth. There are many thermal spring caboodle displays in the Liudaogou-Changbaishan Tianchi-Zheng'oufenshan NE fault, Manjiang-Baishan NWW fault and f4 ring fault. The activity of hot water and deep gas from the earth are very intensity in these faults. The conclusion is that it is an advantaged area for geothermal detection and the best place for volcano detection in the Tianchi section of Liudaogou-Changbaishan Tianchi-Zheng'oufenshan NE fault and Changbaijulong section in f4 ring fault.