黔东北高原斜坡地区4种岩溶地下水系统模式及特点——基于地貌和蓄水构造特征

受深切河谷地貌控制,黔东北大部分地区岩溶地下水深埋且排泄于河谷岸边,以快速的管道裂隙流为主,给地下水资源勘探开发带来了极大的困难,局部地区受蓄水构造控制形成勘探有利的地下水富集区。笔者基于地貌和蓄水构造将研究区岩溶地下水系统归纳总结为深切河谷型、向斜山地型、单斜夹层型和背斜槽谷型4类模式。深切河谷型岩溶地下水系统地下水水力坡度大,地下水以快速的管道流为主,排泄点低,开发利用方式建议直接在地下河出口或天窗中抽提地下水,经济效益明显地区可堵洞成库进行综合利用;向斜山地型岩溶地下水系统发育高位岩溶泉或地下河出口,排泄点高,适合直接引水利用;单斜夹层型岩溶地下水系统在岩性接触带出露一系列接触泉,排泄分散,开发利用方式建议直接利用或抽提岩溶泉水,受夹层隔水顶底板影响局部地区可钻井取水;背斜核部出露寒武系白云岩地层,导致背斜槽谷型岩溶地下水系统含水岩层均匀厚度大,分布大量非全排型岩溶泉,地下水开发适合抽提泉水或钻井抽取地下水。

The Patterns and Characteristics of Four Karst Groundwater Systems in Northeast Guizhou Slope Zone Based on the Landscape and Reservoir Structure

Controlled by deep valleys, karst groundwater level is very deep in most places and the groundwater is excreted along river shore in northeast Guizhou area. The groundwater mainly flows rapidly in pipeline and crack forms, and hence the exploration of groundwater resources is rather difficult; nevertheless, there are also some groundwater enrichment zones controlled by water storage structure. Based on geomorphologic characteristics and geological structure of groundwater storage, the authors summed up the karst groundwater system into four patterns, namely deep valley, syncline mountain land, monoclinic interlayer, and anticlinal aulacogen. For deep valley type, groundwater hydraulic slope is mostly rather steep, and the groundwater is mostly flows rapidly in pipeline form with low level discharge, and hence the exploration should adopt the method of pumping from underground driver outlet and skylight; in large economic benefit area, a reservoir could be built by plugging the hole. For syncline mountain land type, many karst springs and underground river outlets are usually formed in higher position with high level discharge and therefore directly diverting water is the best way. For monoclinic interlayer type, many springs are formed along lithologic boundaries, so we can pump karst springs for direct utilization and can also drill water in local area affected by the roof and bottom of the intercalated bed. For anticlinal aulacogen, a lot of dolomites are distributed near the anticline and aquifer is thick and, therefore, the aquifer has great uniform thickness; in addition, there exist a lot of non all-discharge springs in the karst groundwater system; therefore pumping and drilling seem to be the suitable ways to exploit and develop groundwater.