摘要
我国辽阔的南方,可溶岩分布甚广,包括碳酸盐岩、硫酸盐岩、卤素岩及南海诸岛的礁灰岩。其中碳酸盐岩厚度最大、分布最广,岩溶最发育,地下水蕴藏十分丰富。本文试就碳酸盐岩岩溶地下水作一探讨。
In south China the climate is mild with plentiful precipitation,and soluble rocks are widespread mainly of lifestones and aolomites,up to 3,000-10,000 m thick,and those exposed on the surface cover an area of about 550,000 sq.km.The development of karst is controlled by geological structures,which are responsible for the development of solution fissure systems,solution pipe systems and solution pipe networks in soluble rocks.Groundwater occurs and moves in the solution spaces with different dynamic characters,by which karst ground water may be divided into four types:fissure flow,pipe flow,vein flow and network flow.As the development of karst weakens with depth,the characteristerics of groundwater movement change accordingly;as a result,the distribution of karst ground water exhibits a zonal feature in the vertical section.Generally it may be divided from the top downwards into the cavity-fissure vadose zone,the cavity flow zone and the deep solution-fissure flow zone as well as their respective subzones.Karst ground water is mainly recharged by meteoric water,so its dynamic behaviour changes greatly.The phenomenon of reciprocal transformation of surface water and underground is often observed.Groundwater tends to be enriched in thick-bedded limestone areas and in contact zones between soluble and insoluble rocks;at places where geological structures compound and in tension fissure zones,zones of groundwater enrichment are usually formed.Karst ground water collects near the local base levels of denudation.Unconfined groundwater is widespread from plateaus and slope-mountains to hills and plains,while in buried karst basins there is confined groundwater.In bare karst areas,the adjusted groundwater storage capacity is very large.The hydraulic characteristics vary frequently both laterally and vertically.The run-off conditions and mode may change with time.From recharge areas through run-off areas to discharge areas,the burial depth,hydraulic gradient,flow rate and magnitude of water-level fluctuations of groundwater often show a regular change from the smaller or lower to the bigger or higher and then back to the smaller or lower.The karst ground water is simple in chemical type,generally belonging to neutral or weakly alkaline fresh water of calcium bicarbonate type and calcium-magnesium bicarbonate type,with total dissolved solids less than 0.5 g/l.But the chemical type of the karst ground water occurring in deeply buried karst areas in the Sichuan basin is complicated.On account of differences in karst morphology,soluble rock units and geological structural systems,hydrogeological conditions vary from place to place.The mainland in south China may be essentially divided into eight hydrogeological regions:the Yunnan-Guizhou plateau,Hunan-Guizhou-Guangxi slope-mountain,Hunan-Guangxi-Guangdong-Jiangxi hill-plain,Guangdong-Jiangxi down-faulted basin,western Hubei-northern Guizhou mountain,Sichuan basin,Jianghan plain,and western Sichuan middle-high mountain hydrological regions.
作者
陈文俊
黄显强
宋怀则
董炳维
Chen Wenjun;Huang Xianqiang;Song Huaize;Dong Bingwei
出处
《地质学报》
1981年第2期149-160,共12页
Acta Geologica Sinica
