大地热流值是开展地热研究的基础关键参数。本文在分析历次汇编热流数据的基础上,对2016年以来作者实测(260组)与收集筛选(112组)的热流数据特征进行了说明与分析。新增大地热流数据共372组,在空间上有效填补了西南、西北和东北地区的大片测点空白,提高了东部地区热流测点密度,同时将高质量测点数据占比提升至86.3%,较历次汇编的热流数据在覆盖范围、测点密度、数据质量等方面均有较大提升。依托以上热流数据统计得出我国陆区大地热流平均值为63.8 mW/m²,高于第四次汇编时的全国平均值,其中大部分一级、二级构造单元热流平均值均有提高,青藏高原各构造单元热流平均值则相对降低。典型地热系统热流数据统计显示,高热流背景的存在可明显提高传导型地热资源的分布范围与对流型地热系统的显示温度,但不是两类地热资源形成的控制因素。基于最新成果,对青藏高原低热流区域范围增大、华北平原早期热流“高估”、长白山热流指示岩浆囊存在等现象与问题进行了讨论,指出我国现有热流测点仍相对较少,随着大地热流值测量技术方法的不断更新与规范以及测点数量—质量与覆盖范围的进一步提升,以往对各区域地热分布特征的定性与定量认知可能需要重新审视。以上成果加深了对全国及各区域地热背景的认识,可为区域地热基础研究及资源勘查提供更好的支撑。

Terrestrial heat flow is a key parameter in geothermal researches. Building upon the analyses of previously compiled terrestrial heat flow data, this paper examines the newly measured (260 sets), collected and screened (112 sets) data by authors since 2016. The added heat flow data effectively filled large data gaps in the southwest, northwest and northeast and improved the data density in the eastern region of China mainland. The proportion of high-quality data was improved to 86.3%. Using the latest data the calculated average terrestrial heat flow in China was 63.8 mW/m², higher than the national average value in the fourth compilation, with higher average values found for most of the primary and secondary tectonic units of China and lower values for the Qinghai-Tibet Plateau. The statistics of heat-flow data of typical geothermal systems showed that high average heat flow conditions could significantly improve the distribution range of conductive geothermal resources and the output temperature of hot springs, but were not a controlling factor for the formation of the two types of geothermal resources. Based on the latest terrestrial heat flow data and contour map of China related phenomena and problems were discussed, such as the increase of low heat flow area in the Qinghai-Tibet Plateau, the “overestimation” of early heat flow data in the North China Plain, and the existence of heat flow indicator magma sacs in the Changbai Mountain. It was noted that heat flow monitoring stations in China were still relatively few, and, with the continuous updating and standardization of the measurement methods, plus further improvements in data quantity/quality and sampling locations, the previously assessed regional heat flow characteristics might need to be re-examined. This study deepens the understanding of the status of terrestrial heat flow in China, and can provide better support for regional geothermal basic research and resource exploration.