See presentations from this workshop: Introduction and hands-on orientation

Visual depiction of water flow, maximum temperature, critical temperature and time of year


Raster-based plots (such as raster hydrographs) offer an innovative approach to examining intra- and inter-annual variations in time-series datasets. A gridded graphing approach is used with years as x-values, days as y values and z-values as the magnitude of a grid cell. The resulting raster graphic can be interpreted much like a map, with patches and discontinuities representing seasonal and annual hydrologic patterns. This technique permits new insights into characteristics and disturbances of hydrologic properties and provides additional tools to aquatic ecologists and scientists studying the physical hydrologic environment. This approach also allows hydrologic properties to be identified as patterns within the raster hydrograph. An advanced time-series analysis method using GIS-like techniques will be discussed with examples provided to the participants.


  1. Introduce participants to raster hydrographs
  2. Provide participants with insights and interpretation of temporal data patterns
  3. Provide participants with instructions on how to format data and produce raster plots.

Methods and Tools

This workshop is designed to instruct participants how to create and interpret temporal patterns in streamflow records. Although several software packages can be used to create these plots, the workshop will use SURFER 12 from Golden Software. A free demonstration package will be made available to the participants. Please note that while the demo software is fully functional, it does not save final plots. In any case, the concepts used in the workshop with SURFER are readily transferable to other software packages.


The workshop will be broken into two separate parts:

  1. Introduction Only, from 9-11:30am. To attend only this portion, RSVP here and indicate whether you will attend in person or by webinar. Limited to 60 in-person participants, plus more by webinar.
  2. Hands-on Orientation to Producing Raster-based Graphics, from 12:30-4:30pm. To attend this portion or the all-day event, RSVP here. Limited to 40 participants, must attend in-person.
    For this session, each person needs access to a computer with Windows 7 or 8, and running Microsoft Excel. No files or techniques will be made available for Mac OS or Unix systems. All files and programs needed (except the spreadsheet) to create and analyze raster-based hydrographs will be provided.