湘西洛塔表层岩溶泉的生态环境类型及水文特征

岩溶石山区表层岩溶带的调蓄功能可有效控制石漠化的加剧并为严重缺水地区提供饮用水。文章以湖南洛塔为例,在大量的野外调查基础上,通过对洛塔岩溶区表层岩溶系统生态环境与表层岩溶泉水文特征的对比研究,按生态环境属性将表层岩溶泉分为三种主要类型:森林环境表层岩溶泉、石漠化环境表层岩溶泉及石漠化-森林过渡环境表层岩溶泉。详细论述上述三种表层岩溶泉的发育条件与水文特征:森林环境表层岩溶泉具有持续稳定的水文动态与流量;石漠化环境表层岩溶泉流量与降雨量相对应,动态极不稳定;石漠化与森林过渡环境表层岩溶泉流量排泄峰值具有随泉域植被覆盖率增加而缓和的趋势。按照环境类型对表层岩溶泉进行分类,可直观地显示其特殊的水文特征,有助于岩溶泉的合理开发和综合利用。

Hydrologic features and the eco-environmental classification of epikarst springs in Luota, west of Hunan, China

It is significant for the regulation capacity of epikarst zone in controlling the rock desertification and water supply in the karst mountain areas, where the water shortage is very serious.When we consider Luota karst area, in the west of Hunan, as an example, three typical kinds of epikarst springs were summarized according to the ecological and environmental properties on the basis of a large number of field investigations.They are as follows: epikarst springs in the forest environment, epikarst springs in the rock desertification environment, and epikarst springs in the rock desertification-forest transition environment.The development conditions and hydrologic characteristics of the three kinds of epikarst springs in Luota karst area are discussed in detail in the article.Epikarst springs in the forest environments have a stable hydrologic regime and a continuous water flow; one of epikarst springs in the rock desertification environments is extremely unstable and is in correspondence with precipitation; and in the case of epikarst springs in the rock desertification-forest transition environments, the time of peak discharge is moderately delayed by the increase in the vegetation overcast rate of the spring basin.The classification of epikarst springs, according to their environment types, can directly indicate their particular hydrological features, which can help in the rational development and synthetic utilization of epikarst springs.