Wirkung heterogener Parameterverteilungen auf hydraulische Tests : Analyse und Bewertung

Abstract

Groundwater flow and transport processes are dominated by the heterogeneity of the subsurface. In the last decades, the importance of a detailed description, characterization, and quantification of aquifer heterogeneity became more and more evident. The present work is motivated by the requirement of an improved understanding of the interrelationship of effects resulting from heterogeneity on particular measurements, and by the importance of a detailed characterization of heterogeneity. To account for these issues, two different approaches are applied: 1) Experimental tests conducted to a fractured sandstone block allowing the practical investigation of effects arising from the strongly heterogeneous nature of the sample. 2) A theoretical approach based on the analysis of sensitivity coefficients enabling the improvement of the theoretical comprehension of effects arising from aquifer heterogeneity. The experimental investigation of the fractured porous rock shows effects arising from the heterogeneity of the fractured system. However, the comparison of the experimental results exemplifies the necessity of an improved understanding of the interrelation between an arbitrary parameter distribution and the response of a particular hydraulic measurement. A promising concept to account for this interrelationship is the Sensitivity Coefficient Approach (SCA). The SCA is applied to investigate the intrinsic characteristics of hydraulic tests giving a better understanding of the response of hydraulic tests due to aquifer heterogeneity. As the approach allows the assessment of information from distinct time periods during a hydraulic test, the assignment of estimated parameters to particular spatial information can succeed. Based on the SCA an alternative measuring concept is suggested for an improvement of the conventional approach of hydraulic tests. A proof of the suitability and applicability of the approach is given by numerical examples and field measurements.

Groundwater flow and transport processes are dominated by the heterogeneity of the subsurface. In the last decades, the importance of a detailed description, characterization, and quantification of aquifer heterogeneity became more and more evident. The present work is motivated by the requirement of an improved understanding of the interrelationship of effects resulting from heterogeneity on particular measurements, and by the importance of a detailed characterization of heterogeneity. To account for these issues, two different approaches are applied: 1) Experimental tests conducted to a fractured sandstone block allowing the practical investigation of effects arising from the strongly heterogeneous nature of the sample. 2) A theoretical approach based on the analysis of sensitivity coefficients enabling the improvement of the theoretical comprehension of effects arising from aquifer heterogeneity. The experimental investigation of the fractured porous rock shows effects arising from the heterogeneity of the fractured system. However, the comparison of the experimental results exemplifies the necessity of an improved understanding of the interrelation between an arbitrary parameter distribution and the response of a particular hydraulic measurement. A promising concept to account for this interrelationship is the Sensitivity Coefficient Approach (SCA). The SCA is applied to investigate the intrinsic characteristics of hydraulic tests giving a better understanding of the response of hydraulic tests due to aquifer heterogeneity. As the approach allows the assessment of information from distinct time periods during a hydraulic test, the assignment of estimated parameters to particular spatial information can succeed. Based on the SCA an alternative measuring concept is suggested for an improvement of the conventional approach of hydraulic tests. A proof of the suitability and applicability of the approach is given by numerical examples and field measurements.