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ClimDB/HydroDB (ClimHy) Database Update

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Spring 2005

- Suzanne Remillard and Don Henshaw (AND)

The Climate and Hydrologic Database Project is a component of the LTER Network Information System (NIS), the suite of LTER intersite database modules being created to promote synthetic ecological research.  The ClimDB and associated HydroDB were developed in response to research scientist need for current and comparable climate and hydrologic data summaries for LTER sites and U.S. Forest Service Experimental Watersheds widely used in intersite comparisons, modeling studies, and land management-related studies (Henshaw et al. 1998).  ClimDB is composed of a harvester system that continually captures and updates data from multiple sites into a central database, as well as a web interface that allows graphical display and download of data in common formats (Baker et al.2000). 

Numerous modifications have been made to the ClimDB/HydroDB databases (affectionately referred to as ClimHy) over the past two years.  Visual modifications have been made to both the public and participant web interfaces, and many behind-the-scene revisions have improved the functionality for the database users.  Please note the new ClimHy URLs:

Participant Page -

Public Data Access Page -

The earlier web URLs redirect users to these new pages.  Additionally, both of these web page URL’s are posted on the LTER network intranet. 

One of the major changes is the integration of the ClimDB (primarily NSF-funded) and HydroDB (primarily USFS Research-funded) web pages. This integration has created a better integrated, one-stop shopping portal for climate and hydrology data and metadata.  The data has always been stored in the same database, but the databases had unique access points from the web.  One major enhancement to the Public Data Access Page is a handy interactive table for viewing the sites, stations and variables included in the database by organization: LTER, USFS, or USGS.  Once displayed, the sites, stations and variables can be sorted and re-listed by any displayed field including by the last harvest date or by the most current data harvested.  In addition, the “Data, Plots, and Downloads” allow viewing data as html, downloading as comma or tab-delimited files, or viewing graphical displays that can be saved as image files.  Graphical displays are also improved and include plots of one site versus another or meteorological versus hydrological data, and long-term aggregated means can be displayed alongside monthly or annual data.  Finally, we now dynamically write a PDF that includes complete site metadata for all stations in a single report.

The most recent enhancement is the initiation of our auto-harvest feature, which will initiate a harvest weekly (currently Sunday mornings).  Several sites have already written scripts to automatically harvest, but sites interested in participating in the weekly  auto-harvest feature, please contact the ClimHy Data Manager (  Sites can trigger a harvest as a scheduled event or through a program by using the following URL:<#>&site=<ltersite>

<#> = URL option number (1 or 2)
<ltersite> = Three letter LTER Site code (i.e., AND for Andrews)

Two URLs are maintained in the database for each site (option 1 is the previous ClimDB URL, option 2 is the previous HydroDB URL), but either URL can be used for any data set or scripting program (option 3 is reserved for USGS data harvest only).   These URLs can be edited from the participant page under  “Update Metadata” and then “Research Area Information”.  Sites employing real-time USGS Gauging Station measurements can have this data regularly harvested (LTER Network News, Fall 2003).  Please contact the ClimHy Data Manager.

The User Guide has been updated and a FAQ is planned.  Many of the pages feature a feedback form, which allows the user to submit comments, questions, or suggestions about the various modules or applications.  A data access policy has been established with a data use agreement, disclaimer and general citation.  Data users are encouraged to consult or collaborate with original investigators, and a link to site contact personnel is provided.  ClimHy will adopt the new LTER Data Access and Use Policy, once approved.

What about web services for ClimHy? San Diego Supercomputer Center scientists and LTER Information Managers demonstrated web services architecture and successfully built a prototype involving a few LTER sites (LTER Network News, Fall 2002). While existing architecture has not been replaced for harvesting individual sites using web services, the entire ClimDB/HydroDB database can now be programmatically accessed through web services. Two services allowing access to both raw and aggregated data are described and can be tested from the following URL:

The ClimHY resource continues to grow and increase in use. There are now 6.2 million daily values in the database. All ClimHy web sessions, data views, downloads, plots and feedback are logged into database tables for tracking purposes, and the site is monitored by WebTrends software for general usage statistics. The public web page is averaging 28 visitor sessions per day for the first two months of 2005 compared with 20 sessions per day throughout 2004, with nearly 4000 unique visitors and over 1000 files graphically displayed or downloaded in the past 14 months. Thank you to all contributors who continue to make the ClimHy enterprise a successful venture.


Baker, Karen S.; Benson, Barbara J.; Henshaw, Don L.; Blodgett, Darrell; Porter, John H., and Stafford, Susan G. Evolution of a multisite network information system: the LTER information management paradigm. BioScience. 2000; 50(11):963-978.

Henshaw, Donald L.; Stubbs, Maryan; Benson, Barbara J.; Baker, Karen; Blodgett, Darrell, and Porter, John H. Climate database project: a strategy for improving information access across research sites. In: Michener, William K.; Porter, John H., and Stafford, Susan G., eds. Data and information management in the ecological sciences: a resource guide; 1997 Aug 8-1997 Aug 9; Albuquerque, NM. 1998: 123-127.

Henshaw, Don; Sheldon, Wade; Vanderbilt, Kristin. Introducing the Climate and Hydrology Web Harvester System. The Network Newsletter Fall 2003; 16(2):8.

Vanderbilt, Kristin. SDSC and LTER: Demonstrating a Web Services Architecture. The Network Newsletter Fall 2002; 15(2):9.