장기 양수시험 자료 및 도함수 진단 분석을 활용한 심부 균열암반 현지 수리특성 평가 연구

This study evaluates the hydrogeological properties of deep fractured rock in Korea by applying the diagnostic analysis of head derivative to long-term pumping test data. Pumping tests were conducted in three deep boreholes (Nakmin, Bugok, and Jangjeon) located in granite and volcanic rock formations. The drawdown data measured in these boreholes were analyzed using the derivative method. By simultaneously matching the standard curves of suitable analytical models with both the drawdown curves and their derivatives, the hydraulic conductivity of the fractured rock was determined. The Nakmin borehole was best described by a generalized radial flow model, while the Bugok borehole was best represented by a double porosity model, and the Jangjeon borehole was most consistent with a constant head boundary model. The derivative analysis effectively identified early hydraulic responses (well- bore storage and skin effects), flow regime transitions, and hydraulic boundary effects, which were difficult to detect using conventional drawdown curves alone. The effective application of diagnostic analysis facilitates the optimal selection of analytical models, thereby improving the accuracy and reliability of hydraulic properties derived from pumping tests in fractured rock.