Hydrologic Information Systems: Advancing Cyberinfrastructure for Environmental Observatories

Recently, community initiatives have emerged for the establishment of large-scale environmental observatories. Cyberinfrastructure is the backbone upon which these observatories will be built, and scientists\u27 ability to access and use the data collected within observatories to address research questions will depend on the successful implementation of cyberinfrastructure. The research described in this dissertation advances the cyberinfrastructure available for supporting environmental observatories. This has been accomplished through both development of new cyberinfrastructure components as well as through the demonstration and application of existing tools, with a specific focus on point observations data. The cyberinfrastructure that was developed and deployed to support collection, management, analysis, and publication of data generated by an environmental sensor network in the Little Bear River environmental observatory test bed is described, as is the sensor network design and deployment. Results of several analyses that demonstrate how high-frequency data enable identification of trends and analysis of physical, chemical, and biological behavior that would be impossible using traditional, low-frequency monitoring data are presented. This dissertation also illustrates how the cyberinfrastructure components demonstrated in the Little Bear River test bed have been integrated into a data publication system that is now supporting a nationwide network of 11 environmental observatory test bed sites, as well as other research sites within and outside of the United States. Enhancements to the infrastructure for research and education that are enabled by this research are impacting a diverse community, including the national community of researchers involved with prospective Water and Environmental Research Systems (WATERS) Network environmental observatories as well as other observatory efforts, research watersheds, and test beds. The results of this research provide insight into and potential solutions for some of the bottlenecks associated with design and implementation of cyberinfrastructure for observatory support

Ontomet: Ontology Metadata Framework

Proper description of data, or metadata, is important to facilitate data sharing among Geospatial Information Communities. To avoid the production of arbitrary metadata annotations, communities agree that creating or adopting a metadata specification is needed. The specification is a document, such as the Geographic Metadata Standard (ISO 19115-2003), which provides a set of rules for the proper use of metadata elements. When a community is adopting a metadata specification it has two main concerns: 1) how can an existing specification be adopted, so that elements can be restricted and domain vocabularies be used? and 2) how can a metadata specification be mapped withanother one to achieve interoperability? The two aforementioned concerns are raised due to the fact that: 1) specifications lack domain-specific elements, 2) specifications have limited extensibility, 3) specifications do not always solve semantic heterogeneities and 4) methodologies to create crosswalks among specification have not been formalized. The main goal of this thesis is to present a feasible solution for these problems by providing a flexible environment to allow interoperations of formalized metadata specifications, extensions, crosswalks and domain vocabularies. The main contributions of this thesis are: 1) creation of an abstract model to represent metadata specifications, 2) development of a methodology to extend metadata specifications, called Dynamic Community Profile, and 3) formalization of semantic mappings to perform complex and contextual metadata crosswalks. These three main contributions are encapsulated in a framework called Ontology- Metadata Framework or ONTOMET. ONTOMET has seven components: metadata specification, a domain vocabulary, top-domain ontology, metadata crosswalk, Dynamic Community Profile and vocabulary mapper. A Dynamic Community Profile is a metadata specification, which extends other metadata specifications and infer terms from controlled vocabularies. Vocabulary mappers solve semantic heterogeneities that appear in domain vocabularies and a metadata crosswalk expresses the semantic mappings of two specifications. Also strategies to conceptualize metadata specifications and vocabularies, are presented. Stand alone JAVA Tools and Web programs were created that implemented the methodologies presented, to allow creation of metadata instances and mappings, as well as views of hydrologic vocabularies to facilitate discovery of knowledge and resources in the Web.Ph.D., Civil Engineering -- Drexel University, 200

Geographic Information Systems for Real-Time Environmental Sensing at Multiple Scales

The purpose of this investigation was to design, implement, and apply a real-time geographic information system for data intensive water resource research and management. The research presented is part of an ongoing, interdisciplinary research program supporting the development of the Intelligent River® observation instrument. The objectives of this research were to 1) design and describe software architecture for a streaming environmental sensing information system, 2) implement and evaluate the proposed information system, and 3) apply the information system for monitoring, analysis, and visualization of an urban stormwater improvement project located in the City of Aiken, South Carolina, USA. This research contributes to the fields of software architecture and urban ecohydrology. The first contribution is a formal architectural description of a streaming environmental sensing information system. This research demonstrates the operation of the information system and provides a reference point for future software implementations. Contributions to urban ecohydrology are in three areas. First, a characterization of soil properties for the study region of the City of Aiken, SC is provided. The analysis includes an evaluation of spatial structure for soil hydrologic properties. Findings indicate no detectable structure at the scales explored during the study. The second contribution to ecohydrology comes from a long-term, continuous monitoring program for bioinfiltration basin structures located in the study area. Results include an analysis of soil moisture dynamics based on data collected at multiple depths with high spatial and temporal resolution. A novel metric is introduced to evaluate the long-term performance of bioinfiltration basin structures based on soil moisture observation data. Findings indicate a decrease in basin performance over time for the monitored sites. The third contribution to the field of ecohydrology is the development and application of a spatially and temporally explicit rainfall infiltration and excess model. The model enables the simulation and visualization of bioinfiltration basin hydrologic response at within-catchment scales. The model is validated against observed soil moisture data. Results include visualizations and stormwater volume calculations based on measured versus predicted bioinfiltration basin performance over time

Development of a hydrologic community modeling system using a workflow engine

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, 201

Advanced Computer Technologies for Integrated Agro-Hydrologic Systems Modeling: Coupled Crop and Hydrologic Models for Agricultural Intensification Impacts Assessment

Coupling hydrologic and crop models is increasingly becoming an important task when addressing agro-hydrologic systems studies. Either for resources conservation or cropping systems improvement, the complex interactions between hydrologic regime and crop management components requires an integrative approach in order to be fully understood. Nevertheless, the literature offers limited resources on models’ coupling that targets environmental scientists. Indeed, major of guides are are destined primarily for computer specialists and make them hard to encompass and apply. To address this gap, we present an extensive research to crop and hydrologic models coupling that targets earth agro-hydrologic modeling studies in its integrative complexity. The primary focus is to understand the relationship between agricultural intensification and its impacts on hydrologic balance. We provided documentations, classifications, applications and references of the available technologies and trends of development. We applied the results of the investigation by coupling the DREAM hydrologic model with DSSAT crop model. Both models were upgraded either on their code source (DREAM) or operational base (DSSAT) for interoperability and parallelization. The resulting model operates at a grid base and daily step. The model is applied southern Italy to analyze the effect of fertilizer application on runoff generation between 2000 and 2013. The results of the study show a significant impacts of nitrogen application on water yield. Indeed, nearly 71.5 thousand cubic-meter of rain water for every kilogram of nitrogen and per hectare is lost as a reduction of runoff coefficient. Furthermore, a significant correlation between the nitrogen applications amount and runoff is found at a yearly basis with Pearson’s coefficient of 0.93