随着重庆主城区温泉产业的迅速发展,地热开发的风险性和科学管理地热资源的难度加大。本文从热源、补径排条件、持温能力、矿物组分特征等方面对重庆主城区岩溶地热水资源的形成及特征进行了分析,为地热资源的开发和管理提供参考。主城区地热水资源的储量共计342.75×108 m3,主要赋存于5大高隆起背斜的三叠系嘉陵江组灰岩,盖层为三叠系上统须家河组和侏罗系红色砂泥岩地层,下部隔热层为三叠系飞仙关组砂页岩。地热水热源主要来自地热增温,地热水补给源于大气降水。其形成过程为：大气降水在华蓥山、铜锣山、大娄山及各背斜槽谷的灰岩出露区下渗形成浅层地下水,部分浅层地下水顺灰岩岩层的孔隙裂隙向深部运移,同时地热水顺构造线方向向南或北倾没端径流,在运移过程中不断溶解和富集矿物盐及微量元素,并以传导型的地热增温方式提高深部循环水的温度,在河流深切峡谷地段或构造薄弱部位出露成泉,或以人工钻井形式排泄。热储层埋深较大,一般为2000~2500 m,地热水深部循环缓慢、形成周期长,年龄约8000~17000年。近年来,人类活动,特别是隧道开挖对地热水资源造成了严重的影响,建议加强地热资源开发的监管和环境保护,以确保地热资源的可持续利用。%In recent years,with rapid development of geothermal industry in the main urban area of Chongqing,both the risk of development and difficulty in scientific management of geothermal resources have increased.In order to realize the reasonable exploitation of water resources,to avoid human overexploi-tation,and to ensure the sustainable development and utilization of geothermal resources,this article analy-zes the characteristics and formation of karst water resources in this area,involving the heat source,re-charge,runoff,discharge conditions,holding capacity,and mineral components.The results suggest that this area has a great reserve of geothermal water which is 342.75×10 8 m3 in total,primarily existing in the Triassic Jialingjiang Formation limestone of five big uplifted anticlines.The cap rocks are Upper Triassic Xu-jiahe Formation and Jurassic red sandy mudstone,underlain by Triassic Feixianguan Formation sandy shale as the heat insulation layer.The heat of the geothermal water comes from geothermal temperature increas-ing,and rainfall supplies the water.Its formation process is as follows:Meteoric water infiltrates downward into the outcropped limestone to form underground water in the shallow subsurface in Huayingshan,Tonglu-oshan,Daloushan and valleys of other anticlines.Part of this water migrates toward depth along cracks of the limestone.Meanwhile geothermal water flows along structural lines to north or south,resulting in run-offs.During the migration,the water dissolves and accumulates mineral salt and microelements,and en-hances its temperature by thermal conduction.It exposes as springs at valley sections with river incision or at structural weak portions,or is released by artificial drilling wells.The thermal reservoirs are usually as deep as 2 000- 2 500 m,where the geothermal water cycles slowly with ages of formation as long as 8 000 -17 000 years.In recent years,human activity,particularly tunnel excavation has imposed serious impact on geothermal water resources in the study area.We suggest that monitoring and management of development to these resources and environmental protection should be strengthened to ensure their sustainable utiliza-tion.
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