About CUAHSIThe Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) is an organization representing 120+ universities in the US and 11 international affiliates. As part of its mission, CUAHSI supports the development of cyberinfrastructure for the hydrologic sciences. The CUAHSI HIS (Hydrologic Information System) project is a multi-year multi-institution effort focused on consistent management and integration of observational data available from several federal agencies (USGS, EPA, USDA, NOAA, etc.) as well as published by academic investigators.

Databases Analysis

Models

Rainfall & Snow

Water quantity and qualityRemote sensing

MeteorologySoil water

Enhancement of hydrologic science by facilitating user access to more and better data for testing hypotheses and analyzing hydrologic processesThis involves:• assembling and querying integrated nations’s repository of water data• linking small integrated research sites with global climate models• integrating data from multiple disciplines to understand controls on hydrologic cycle• developing mechanisms for publishing heterogeneous government and academic data

System ComponentsService-oriented Architecture for Hydrologic DataCUAHSI HIS develops service-oriented architecture for hydrologic research and education, to enable publication, discovery, retrieval, analysis and integration of hydrologic data. The project team has defined a common information model for organizing hydrologic observation data, designed a common exchange protocol (Water Markup Language), created a collection of SOAP web services (WaterOneFlow services) that provide uniform access to different federal, state and local hydrologic data repositories, and developed mechanisms for ontology-based data registration and discovery.

CUAHSI member universities in the US

HIS Central

Observations Data Model WaterML

WaterML

Water Data Web Services Hydrologic OntologyThis system is implemented as a collection of HydroServers deployed at NSF Hydrologic Observatory test beds, at other partner universities and agencies, and internationally. HydroDesktop and other HIS clients are used in research and teaching.

Deployment

Science Goals

End-to-end three-tier solution: frompublication and registration to discovery, analysis and synthesis of hydrologic observation data

Vocabularies used by each data source, are matched up with a common controlled vocabulary. In the process of water data service registration, variable names in each source are associated with concepts in a CUAHSI HIS ontology. This provides for semantics-aware data discovery and integration regardless of naming conventions or synonyms used by individual sources.

Observations Data Model (ODM) is a standardized and community-tested relational schema for storing hydrologic observation data and a sufficient amount of metadata, in a form that aids in effective sharing

and analysis of information from disparate sources.ODM Data Loaders support efficient ingestion of data and metadata from files or data streams. ODMTools software is designed to manage and quality control of information in ODM.

Water Data Web Services provide a uniform way to query and access observations data and metadata within HIS, regardless of intricacies of individual data sources. The following core methods are supported: • GetSites • GetSiteInfo• GetVariableInfo• GetValues

The web services return WaterML-compliant documents to HIS clients. The list of data sources accessible via services include: USGS National Water Information system (Daily Values, Ground Water, Instantaneous Irregular Data, Unit Values), EPA STORET, USDA Snowpack Telemetry (SNOTEL), NCDC ISH and ISD, MODIS,DAYMET, NAM12K, as well as over 50 observation networks contributed by academic research projects and made accessible via ODM Generic Web Services.

While syntactic heterogeneity is managed by water data being described using ODM and WaterML, and accessed via uniform Web services, semantic differences across observation networks require a different approach.

At the general level, CUAHSI HIS includes three key components: data publication platform (HydroServer); data discovery and integration platform (HydroCatalog) and a data synthesis and research platform (represented by HydroDesktop).

Links CUAHSI HIS: http://his.cuahsi.orgHIS Central: http://hiscentral.cuahsi.org/HydroDesktop: http://www.hydrodesktop.orgHIS Wiki @ SDSC : http://river.sdsc.edu/wikiMailing list: subscribe at https://lists.sdsc.edu/mailman/listinfo/his

Hydrologic Information System for the Nation

Spatial Information Systems Lab, San Diego Supercomputer Center, University of California San Diego, zaslavsk@sdsc.edu

HydroCatalog

HydroServer

HydroDesktop

Water Markup Language (WaterML) is an XML schema for hydrologic time series, designed to support exchange of hydrologic information within HIS. It contains general constructs describing sites, variables, time series, and data values. Designed to be the least barrier for adoption by hydrologists, WaterML relies on both the ODM relational schema and the data and metadata available from government hydrologic repositories (NWIS, EPA).

Catalog content (09/2010): 60+ public services 15,400+ variables 1.8+ million sites 23.3 million series 4.7 billion data values

HydroDesktop is a free and open source desktop application developed in C# .NET that serves as a client for CUAHSI HIS water data web services. Hydrodesktop supports processing of both geospatial data and observational time series. It is designed as a single comprehensive environment for analysis and synthesis of hydrologic data, development of local analytical databases, management of time series collections, and model and workflow integration based on local and remote services. In particular, HydroDesktop relies on the notion of a hydrologic theme, which is defined as a thematically organized collection of hydrologic time series expressed as a spatial database. Hydrologic themes allow users to query and subset hydrologic time series based on the numeric values of observations stored in a theme.

ODM ODM ODM

WaterOneFlow WaterOneFlowWaterOneFlow

HydroServerDatabase

ODM Databases and WaterOneFlow Web Services

ArcGIS Server Spatial Data Services

SpatialServices

WaterOneFlowServices

Map Server Time Series Analyst HydroServer Website HydroServer Capabilities Web Service

HydroServer Database

Configuration Tool

Test bed HydroServers

Central HIS servers

HydroDesktop

Matlab, IDL, R

ArcGIS

Excel

Programming (Java, C, VB)

Desktop clients

Customizable web interface (DASH)

Modeling (OpenMI)

Global search (Hydroseek)

Water Data Web Services, WaterML

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HIS LiteServers

External data providers

Other popular online clients

ODM DataLoader

Streaming Data Loading

Ontology tagging

(Hydrotagger)

WSDL and ODM registration

Data publishing

ODMTools

Server config tools

HIS CentralRegistry & Harvester

WaterML 1.x has been adopted by USGS and NCDC. WaterML 2.0 is the next version being standardized by the OGC/WMO Hydrology Domain Working Group.

The HydroServer software stack has enabled individual scientific investigators and research groups to publish their hydrologic observations and make them available within CUAHSI HIS. It is available in two versions: a complete HydroServer suite, which relies on commercially available components, and an HIS Server Lite, composed of freely available components. To publish hydrologic time series, data managers can use various data loaders to ingest observational data into instances of ODM, perform quality control of the data, configure web services over the ODM databases, and customize an online mapping application for accessing the new data.

Water data web services are registered at the Central HIS service registry. The HISCentral application harvests observation metadata from the service (sites, variables, and periods of record that are accessed via the service) at regular intervals and appends it to the central metadata catalog. In addition, HISCentral supports semantic tagging of the registered data, by associating the harvested variables with concepts from a hydrologic ontology. HydroCatalog web services enable data discovery by HIS clients such as HydroDesktop.

Number of data requests brokered by

the catalog has been growing rapidly

Federal agency data services in HISCentral