中国岩溶2017，Vol.36Issue(5)：727-735,9.DOI:10.11932/karst2017y29
基于钻孔抽水试验和示踪试验的岩溶地区含水层结构研究
Aquifer structure of karst areas derived from borehole pumping and tracer tests
摘要
Abstract
Karst aquifers have strong heterogeneity and anisotropy.The investigation and understanding of their spatial structure are the important foundation for research of groundwater flow and contaminant migra-tion.However,hydrogeology surveys are very difficult to conduct in karst areas due to their special geologic structure.To tackle this problem,this work conducted pumping tests and multiple tracer experiments (sodi-um fluorescein and rhodamine,fluorescent whitening agent)at the same.Using the Theis standard curve comparison,we analyzed pumping test data and calculate the permeability tensors of test sites.The structure properties of aquifers were determined by the results of the tracer tests.The calculated coefficient of trans-missibility in the main direction of permeability tensor in the study area are:0.297 m2 ·h-1 and 0.028 m2 · h-1 ,specific yield is 1.19e-04 and predominant direction is east by south 18.47°.Tracer recovery rates in the tracer tests under the pumping condition for three kinds of traces are:fluorescein sodium 97.98%,rho-damine B 47.34%,and fluorescent whitening agent 39.54%.The average flow velocities are 0.378 m·h-1 , 0.3 m·h-1 and 0.14 m·h-1 ,respectively.They reflect the karst pores and fractures are small in the study area,tracer migration is slow and needs long time.The BTC curve of fluorescein sodium and fluorescent whitening agent is of unimode type,the BTC curve of rhodamine B is multi-peak,showing the development of single dominant fractures and relatively uniform fractures in the study area.At the same time,the direc-tion of maximum recovery of the tracer is in accordance with the main direction of the permeability tensor from pumping tests.The results can provide a method and basis for precise description of karst aquifer char-acteristics and the determination of physical parameters of hydrological models.关键词
岩溶区/抽水试验/各向异性/示踪试验/渗透张量Key words
karst region/pumping test/anisotropic/tracer test/permeability tensor分类
天文与地球科学引用本文复制引用
吕全标,胡晓农,曹建华,黄芬,朱昊..基于钻孔抽水试验和示踪试验的岩溶地区含水层结构研究[J].中国岩溶,2017,36(5):727-735,9.基金项目
国家自然科学基金项目(J216065) （J216065）
