Development of a hydrologic community modeling system using a workflow engine

Abstract

Community modeling is a comparatively new paradigm that emphasizes on developing evolving modeling systems through a collective effort. It has gained growing attention within the hydrologic communities because the demand of developing more holistic-view model systems addressing chemical, physical, and biological processes within the geo volumes of the hydrologic cycle. The development of a community modeling system involves a number of technical issues including how to seamlessly integrate various models/modules especially to mediate their communications and executions, how to improve development efficiency by migrating legacy codes, and how to improve model provenance and repeatability of model runs to name just a few. The major objective of our studies is to develop a hydrologic community modeling system (HCMS) that allows constructing seamlessly integrated, workflow-based hydrologic models with swappable and portable modules for retrieving data from various data sources, pre-processing, modeling, and post-analysis. The HCMS is built on the Microsoft’s TRIDENT workflowengine which assists in tackling many of the above technical issues during its development. Four libraries are incorporated into HCMS, i.e. a data retrieval, a dataprocessing, a hydrologic computation and a data analysis library, which support to access data from numerous online data repositories using SOAP/FTP protocols or from local data stores, transform source data into model inputs, perform hydrologic modeling, and analyze model results, respectively. It can potentially be applied to anywhere in the nation due to its access to data sets of nationwide coverage, and can reduce the workload of conducting hydrologic modeling tasks to a great level. Besides its feature of supporting parallel or concurrent executions as well as distributing computations in GRID environment can improve run-time efficiency. This thesis comprises three independent papers, which present the studies on (1) the current efforts that have been or are beingmade for community modeling, (2) the development of the HCMS using the Microsoft’s TRIDENT workflow engine, (3) the assessment on the applicability and performance of the TRIDENT-shelled HCMS by applying it to conduct hydrologic studies on the Schuylkill watershed located in the Southeastern Pennsylvania.%%%%Ph.D., Civil Engineering – Drexel University, 2011