摘要
系统采集了黔北山地某农业区地表水与地下水水样,分析测定各水体主要离子化学组成。结果表明:地表水中除大茅坡山顶水体呈弱酸性之外,其余水体整体呈中性偏弱碱性,地下水主要为碎屑岩裂隙水,pH整体呈弱酸性。水体中离子浓度均呈现出从高海拔到低海拔离子含量增加的规律。根据阿列金分类法,大茅坡山顶和大窝凼的水体中,Ca^(2+)和SO_4^(2-)分别占阳离子和阴离子总量的75.3%和57.9%,水化学类型是[S]CaⅡ型。相比,大茅坡沟谷和后槽顶的水体中,Ca^(2+)和HCO_3^-是优势离子,占阳离子和阴离子总量的比重分别为76.7%和53.4%,水化学类型是[C]CaⅠ型,研究区阳离子间浓度关系均为Ca^(2+)>Na+>Mg^(2+)。通过Gibbs模式图分析,该农业区水体主要受碳酸盐类和硅酸盐类风化作用控制。农耕区水体中的Ca^(2+)和Na^+还会受到表层土壤离子交换、大气输入及人类活动干扰等的影响,K^+、Cl^-、NO_3^-浓度也明显增加。随着土地利用方式转化,农业活动对水体离子浓度的贡献值增大。
We collected surface water and ground water samples from the agricultural areas of the mountainous regions in northern Guizhou Province and measured the major ions.The results show that all surface waters are neutral and mildly alkaline except the water in Damaopo Mountain which appears to be faintly acid,the same as all ground water samples.With decreasing elevation,the ion concentrations are found to increase considerably in the experiment region.According to the Arliekin＇s classification,in the water of Dawodang and the top of Damaopo Mountain,Ca^2＋accounts for 75.3% of the total major cations,HCO3^-accounts for 57.9% of the total major anions,whose hydro-chemistry type is[S]CaⅡ.By contrast,among the water in Houcaoding and gully streams of Damaopo Mountain,HCO3^-accounts for 53.4% of the total major anions,Ca^2＋accounts for 76.7% of the total major cations,whose hydro-chemistry type is[C]CaⅠ.The magnitude relationship of cation concentrations in the researched area is Ca^2＋〉Na＋〉Mg^2＋.According to source study of major ions through Gibbs boomerang envelope,the chemical compositions of the waters in the study region are controlled by rock weathering and dissolving.In addition,the concentration of Ca^2＋ and Na＋in cultivation areas will be impacted by ion exchange in the surface soil,the atmospheric input and the disturbance of human activities.The concentration of K^＋,Cl^-,NO3^-increases significantly.As a way of land use conversion,the contribution values of agricultural activities on water ion concentration increase.
出处
《中国农村水利水电》
北大核心
2016年第4期63-68,73,共7页
China Rural Water and Hydropower
基金
国家科技支撑计划课题(2011BAC09B01
2006BAC01A16)
重庆市自然科学基金重点项目(CSTC2009BA0002)
关键词
农业区
水环境
水化学特征
主离子
Gibbs图
typical agricultural areas
aquatic environment
hydro-chemistry
major ion
Gibbs boomerang envelope
