摘要:
通过对典型岩溶丘陵区地下水进行水化学特征及地球化学敏感性的研究表明,该地下水系统水化学特征阳离子以Ca2+、Mg2+为主,阴离子以HCO-3、NO-3、SO 2-4为主,受水岩作用及人类活动共同影响;Mg2+/Ca2+受岩性控制,流经白云岩地层最高,灰岩夹白云岩次之,灰岩最低;研究区岩溶地下水表现出较高的地球化学敏感性.阳离子以Ca2+最为敏感,其次为Mg2+,阴离子以HCO-3最为敏感,其次为NO-3,元素的地球化学敏感性大小依次为:HCO-3>Ca2+>Mg2+>NO-3>SO 2-4>Cl->Na+>K+;以敏感性最强的敏感因子HCO-3对研究区岩溶地下水进行敏感性等级划分.研究区低敏感性的水点仅占7.27%,中敏感性的水点占25.45%,高敏感性的水点占67.28%.通过地球化学敏感性划分统计结果显示,对该地区地下水的保护显得十分重要且迫切.
Abstract:
This study investigated hydrochemical characteristics and geochemical sensitivity of groundwater in a typical karst hilly region.The results indicate that Ca2 + and Mg2 + are the main cations and HCO -3 and NO -3 are the main anions in the karst groundwater system,which are affected by water-rock interaction and human activities;groundwater system,which is affected by water-rock interaction and human activities.The result also indicates the ratio of Mg2 +/ Ca2 + ,controlled by lithology,is the highest in the dolomite second highest in the limestone dolomite,and the lowest in limestone.In general,the karst groundwater in the study area shows a high geochemical sensitivity which follows the order as HCO -3 >Ca2 + >Mg2 + >NO -3 >SO 2 -4 > Cl- > Na+ > K+ .In particular,the cation Ca2 + is the most sensitive,followed by Mg2 + ,while HCO -3 is the most sensitive inthe anions,followed by NO -3 .The sensitivity level of the karst groundwater in the study area is classified by the most sensitive factor HCO -3 .Consequently,the low sensitive water spots account for only 7.27%,the medium sensitive ones account for about 25.45%,while the highly sensitive ac-count for about 67.28%.These statistic results of the geochemical sensitivity division show that the protec-tion of groundwater is very important and urgent.