湖南洛塔表层岩溶带水文地球化学特征初步分析

PRELIMINARY ANALYSIS ON HYDROGEOCHEMICAL CHARACTERISTICS OF THE EPIKARST ZONE IN LUOTA, HUNAN

湖南洛塔为西南具有一定代表性的溶丘洼地型岩溶区,本文利用近两年来洛塔水环境监测资料,进行洛塔表层岩溶带的水化学和水温场特征的研究,认为该表层岩溶带的水化学和水温场的特征与气候、生态环境和岩溶含水介质等多种因素明显相关。不同影响因素对表层岩溶水水化学组分的作用有所不同,表层岩溶带岩溶水受气候影响较大,大气降水的降雨强度,直接影响到地下水化学组分含量的大小,总硬度和HCO-3含量与降雨量呈明显的负相关关系,植被、土壤的覆盖程度与水化学组分含量高低呈正相关性。

Luota is a typical karst area of karst hilldepression in southwest China. In this paper, characteristics of hydrochemical field and water temperature field of the epikarst zone in Luota are studied by monitor data of water environment in the recent two years. It is concluded that the origin of hydrochemical field and water temperature field is evidently related with some factors, such as climate, ecological environment, karst waterbearing medium. Different influencing factors have different effects on hydrochemical component of epikarst water while epikarst water is affected largely by climate. Rainfall is the main recharge for epikarst water, of which the intensity directly affects hydrochemical component, while total hardness and HCO3 are evident negatively related to rainfall. As for a highcold mountainous area, the temperature of epikarst water is quite low and varies with the season. The impact of ecologic environment on hydrochemical component of the epikarst water is that the covered rate of vegetation and soil is positively related to hydrochemical component of the water.