广西岩溶区地下河分布特征与开发利用

广西岩溶地区已查明地下河445条,其分布受地质、地貌条件控制。地下河出口主要分布于灰岩地层,在白云岩地区分布最低。以峰丛洼地区地下河分布数量最多、规模大,其次为峰林谷地和平原区,岩溶丘陵区地下河数量少、规模小。不同岩溶地貌区的地下河及开发利用带来不同的环境问题,峰丛洼地区以内涝最严重,峰林谷地和平原区的地下河水开发常造成塌陷,岩溶丘陵地区的地下河水污染严重。开发利用方式主要为出口建坝蓄水,天窗提水,地下河堵洞成库,堵截地下河引水发电,建地表、地下联合水库。

Distribution and exploitation of underground rivers in karst areas in Guangxi

There are 445 underground rivers in karst areas in Guangxi.Distribution of underground rivers is evidently controlled by geological and geomorphologic conditions.The exit of underground rivers occurs mainly in limestone areas,occupying 80% of the total river ones,with a density of 5.33/1 000km~2.The lowest exit density of underground rivers occurs in the dolomite areas.The most and biggest underground rivers are in the peak-cluster depression areas,and the next are in the peak-forest valley and plain areas.In karst hill areas,underground rivers are sparse and short.The peak-cluster depression,peak-forest plain and karst hill are three main kinds of karst landforms in Guangxi.The underground rivers and their exploitation in each of these karst landforms lead to different environmental problems.For example,water-logging in the peak-cluster depression is the most serious problem.Exploitation of underground rivers in the peak-forest plain lead to collapse,and pollution of underground water is a key problem in the karst hills.There are five kinds of exploiting manners: building dams in the exit of underground rivers to store water,taking water from the windows,stopping underground water in cave to establish a reservoir,building dams in the underground river to lead water for power plant,and building dams in the surface river bed to form a joint reservoir of surface water and ground water.