甘肃民勤绿洲北部荒漠区地下水水化学特征及成因分析  

Hydrochemical characteristics and cause analysis of groundwater in the northern desert area of Minqin Oasis

作　　者：田辽西 刘德玉 TIAN Liaoxi;LIU Deyu(Institute of Hydrogeology and Engineering Geology of Gansu Bureau of Geology and Mineral Exploration and Development,Zhangye,Gansu,734000;Key Laboratory of Groundwater Engineering and Geothermal Resources in Gansu Province,Lanzhou,730050;Gansu Institute of Geological Environment Monitoring,Lanzhou,730030)

机构地区：[1]甘肃省地矿局水文地质工程地质勘察院,甘肃张掖734000 [2]甘肃省地下水工程及地热资源重点实验室,兰州730050 [3]甘肃省地质环境监测院,兰州730050

出　　处：《地质论评》2023年第5期1834-1844,共11页Geological Review

基　　金：民勤县北部找水靶区水文地质勘查项目;甘肃省地下水工程及地热资源重点实验室开放基金项目(编号:201908)的成果。

摘　　要：民勤绿洲北部荒漠区作为国家北方防沙带的重要组成部分以及石羊河下游生态保护治理区,在地下水水化学方面的研究程度很低。在野外调查、勘探及采样测试的基础上,综合运用数理统计、Piper三线图、离子相关性分析、Gibbs图及离子比例系数等方法对民勤绿洲北部荒漠区的地下水水化学特征及成因进行了研究分析。结果表明:研究区地下水溶解性总固体以及硬度值较高,水化学类型主要为Cl^(-)·SO_(4)^(2-)-Na^(+)型。地下水水质总体能够满足生态屏障区种植旱生、耐盐植被的需要。地下水水化学演化是由蒸发浓缩作用主导、风化溶解和阳离子交换共同作用的结果。地下水中超标的高硝酸盐氮水与牲畜粪便污染有关,高氟水的形成受原生地质环境背景影响。成果不仅进一步提高了区内地下水水化学的研究程度,亦可为民勤绿洲区保护、北方防沙带以及石羊河下游生态保护治理区建设提供科学依据。As an important part of the northern sand control belt and an ecological protection area in the lower reaches of Shiyang River,the northern desert area of Minqin Oasis has a low research degree in groundwater hydrochemistry.On the basis of field investigation,exploration and sampling test,the hydrochemical characteristics and cause of groundwater in the northern desert area of Minqin Oasis were analyzed by using the methods of mathematical statistics,Piper trigram,ion correlation analysis,Gibbs diagram and ion proportion coefficient.The results show that the total dissolved solids and hardness of groundwater in the study area are relatively high,and the main hydrochemical type is Cl^(-)·SO_(4)^(2-)-Na^(+).The groundwater quality can generally meet the needs of planting xerophyte and salt-tolerant vegetation in the ecological barrier area.The hydrochemical evolution of groundwater is dominated by evaporation concentration,accompanied by weathering dissolution and cation exchange.The excessive high nitrate nitrogen in groundwater is related to livestock manure pollution,and the formation of high fluoride water is affected by the original geological environment background.The results not only further improve the research level of groundwater hydrochemistry in the area,but also provide scientific basis for Minqin Oasis protection,the construction of the northern sand prevention belts and the ecological protection and control area in the lower reaches of Shiyang River.

关 键 词：民勤绿洲 荒漠区 地下水化学特征 高硝酸盐氮水 高氟水 

分 类 号：P641.12[天文地球—地质矿产勘探]