Structure of karst groundwater system and its water exploration in Wumeng Mountain area

Abstract

The Wumeng Mountain Contiguous Zone in China always suffers from deficiency of groundwater resources.The Zhaotong area of Yunnan Provience belongs to the Wumeng Mountain area, which was the key area.We carried out geological survey, spring flow statistics and water quality evaluation in karst stratum.The strip karst area, which always located in ridge-valley area, with many target aquifers, karst shallow.Groundwater was concentrated in the core of anticlinoria and both wings, the core of syncline and fault zone.The buried karst water mainly concentrated in the paleo-karst stratum in Zhaolu fault basin, and covered below Tertiary system.Most chemical type of groundwater was determined as HCO3 and HCO3·SO4 type.The strip and buried karst water account for 96.73% and 92.93% respectively.The comprehensive water quality evaluation results of 80.84% simple analysis and 64.41% total analysis were classified as Ⅰ-Ⅲ.We suggest that large flow springs more than 50 L/s should be extracted, diverted and stored for winter use.Combined with geophysical exploration and drilling verification, the target aquifer was more successfully found in water-rich section of strip and shallow buried karst areas.Firstly, the high-density electrical method and combined profile method were conducted to find out the karst fracture zone and fault.Then, the IP sounding was set to explore the depth of the aquifer with high polarizability.Finally, the water supply segment and water inflow were determined by comprehensive logging and drilling.The rate of successfully extracting water was 86.67%.Then, we could recommend the well location.

Keywords

• karst groundwater system
• strip karst of ridge-valley area
• water-rich segment
• geophysical exploration
• groundwater exploration