Jos_von_Asmuth_Thesis.pdf - repository

`Ü~éíÉê=S=NRM=Abstract:The program Menyanthes combines a variety of functions for managing, editing,visualizing, analyzing and modeling hydrogeologic time series. Menyanthes was initiallydeveloped within the scope of the PhD research of the first author, whose primary aimwas the integration of data and physically-based methods for modeling time series ofgroundwater heads. As such, time series analysis forms the heart of Menyanthes. WithinMenyanthes, time series can be modeled using both the ARMA and PIRFICT methods. ThePIRFICT method is a new method of time series analysis that has practical advantages andfacilitates physical interpretation and implementation of knowledge on physical behavior.Analytic solutions to specific hydrogeologic problems may be used as response function,along with their physically-based parameters. A more general approach is possible usingSkew-Gaussian distribution functions, which prove to fit the behavior of hydrogeologic(and other) systems well. Use of such functions within the PIRFICT method substantiallysimplifies the model identification procedure, as compared to the traditional Box-Jenkinsprocedure. PIRFICT models may be fitted to a large number of time series in batch. Spatialpatterns that emerge in the results provide useful, additional, and independentinformation, which adds another dimension to time series analysis. Their interpretation issupported by the spatial visualization and analysis tools of Menyanthes. The PIRFICTmethod also facilitates the integration of time series and spatially-distributed models via,e.g., moment-generating differential equations. The PIRFICT method may prove to be ofuse for other types of time series as well, both within and outside the realm ofenvironmental sciences...…………………………………………………………………………………………….….