珠江三角洲地区酸性地下水分布特征及其影响因素研究

Study on distribution characteristics of acid groundwater and its influencing factors in the Pearl River Delta

珠江三角洲地区酸性地下水(pH<6.5)分布范围占全区面积的3/4,区域地下水酸化较普遍,已成为最大的区域地下水环境和生态问题之一。本研究通过珠江三角洲地区地下水pH值及地下水常规无机成分,对地下水酸化的空间分布规律与影响因素进行分析,结果发现:pH<6.5的偏酸性地下水主要分布于东、北、西的低山、丘陵地区,主要土地利用类型为果林用地及农田用地,主要含水介质类型为基岩裂隙水,同时分布有松散岩类孔隙水、还有碳酸盐岩类裂隙溶洞水;pH≥6.5的地下水主要集中在三角洲中心平原区,主要土地利用类型为城市用地,地下水类型为松散岩孔隙水。

The distribution of acid groundwater （pH 〈 6.5 ） in the Pearl River Delta area is 3/4 of the whole area, and regional groundwater acidification is more common. It has become one of the largest regional groundwater environmental and ecological problems. In this study, the spatial distribution of groundwater acidification and its influencing factors were analyzed by the groundwater pH values and conventional inorganic constituents in the Pearl River Delta region, the results showed that acidic groundwater pH 〈 6.5 mainly distributed in the East, North and west low mountain and hilly areas, the main land use types of land for forest land and farmland, the main aquifer type is bedrock fissure water, and the distribution of pore water in loose rock and karst fracture water; The groundwater of pH ≥6.5 is mainly concentrated in the plain area of delta center. The main land use type is urban land, and groundwater type is loose rock pore water.