西藏尼木地区遥感数据地温反演与地热异常预测

Land surface temperature using remote sensing data inversion and prediction of geothermal anomaly area in Nimu, Xizang(Tibet)

为探明西藏尼木地区地热资源的空间分布及指导该区地热资源的勘探与开发,选取2010年1月21日与2月22日的Landsat 5TM数据,基于单波段的单窗算法进行地表温度反演,并利用ArcGIS软件分析了地表温度、已有地热异常点、构造及人类活动之间的关系,对该区潜在的地热异常进行预测。结果表明,地表温度分别为:-21.75~40.65℃,-18.95~46.45℃,二者进行对比分析表明反演结果符合实际且结果可靠。依据遥感数据地温反演结果,发现区内温度异常区比背景区高10 K以上,研究区存在未被发现的隐伏断层及地热活动异常信息,由此划分出21个潜在地热异常区。结论认为位于亚东—谷露与雅鲁藏布江缝合带交汇区的尼木地区地热异常特征明显,勘探开发前景广阔;在高寒缺资料区基于遥感单窗算法进行温度反演,可以有效提取地热异常信息,帮助预测具有开发前景的地热异常区,并进一步识别圈定具有勘探意义的靶区。

In order to explore the spatial distribution of geothermal resources and guide the exploration and development of geothermal resources in Nimu area, Tibet, the Landsat 5 TM data of January 21 and February 22, 2010 were selected to carry out geothermal inversion based on Mono-window Algorithm. The relationship among surface temperature, existing geothermal anomaly points, structure and human activities was analyzed by using ArcGIS software, and the potential geothermal anomaly in this area was predicted. The results show that the surface temperatures are-21.75~40.65 ℃ and-18.95~46.45 ℃, respectively. Combined with the regional characteristics, the inversion results are practical and reliable. According to the results of surface temperature inversion based on remote sensing data, it is found that the temperature anomaly area in the study area is more than 10 K higher than the background area, and there are hidden faults and abnormal geothermal activity information in the study area. Thus, 21 potential geothermal anomaly areas are classified. It is concluded that Nimu area, located at the intersection of Yadong—Gulu and Yarlung Zangbo suture zone, has obvious geothermal anomaly characteristics and broad exploration and development prospects. Surface temperature inversion based on Mono-window Algorithm can effectively extract geothermal anomaly information, help predict geothermal anomaly areas with development prospects, and further identify and delineate target areas with exploration significance.