title: The nested superblock approach for regional-scale analytic element models.
abstract: A new approach is presented for improving the computational efficiency of regional-scale ground water models based on the analytic element method (AEM). The algorithm is an extension of the existing "superblock" algorithm, which combines the effects of multiple analytic elements into Laurent series and Taylor series (superblock expansions). With the new "nested superblock" formulation, Laurent series are nested in a hierarchical (quad-tree) data structure with direct mathematical relationships between parent and child superblock coefficients. Nested superblocks significantly accelerate the evaluation of the complex potential and discharge function in models that contain a large number of analytic elements at multiple scales. This evaluation process, the primary computational cost of AEM models, is required to determine the element coefficients, generate contour plots, and trace pathlines. The performance of the nested superblocks is demonstrated with a simplified model based on the Lake Ontario watershed geometry comprising thousands of hydrogeologic features at multiple geographic scales.
authors.affiliation: Department of Civil Engineering, University of Waterloo, Ontario, Canada. jrcraig@uwaterloo.ca
authors.forename: James R
authors.initials: JR
authors.lastname: Craig
authors.forename: Igor
authors.initials: I
authors.lastname: Janković
authors.forename: Randal
authors.initials: R
authors.lastname: Barnes
mesh_terms: D000328:Adult; D000465:Algorithms; D002648:Child; D004784:Environmental Monitoring; D020342:Finite Element Analysis; D005843:Geography; D055593:Geological Phenomena; D005844:Geology; D006114:Great Lakes Region; D006801:Humans; D008962:Models, Theoretical; D018570:Risk Assessment; D014872:Water Movements; D014873:Water Pollutants / Q000633:toxicity; D014881:Water Supply
chemical_list: D014873:Water Pollutants