Coffee Hour talk on "Mapping Hydrography with the Best of Intentions"

March 26, 2010

University of Colorado-Boulder geography professor Barbara "Babs" Buttenfield will give a Coffee Hour lecture at 4 p.m. Friday, March 26, in 112 Walker.

Her talk is titled "Mapping Hydrography With the Best of Intentions." The public is invited to attend. Refreshments will be served at 3:30 p.m. in 319 Walker.


I work on generalization, multi-scale database design, and water. Generalization is the sequence of processing steps that modify the content, geometry, and appearance of spatial data. Generalization used to be exclusively for cartographic display, but recently it has been adopted for modeling purposes such as global change, regional flood impact analyses, landscape futures planning, and other problem domains for which the geographic process in question has a very large spatial footprint, or where model uncertainties are high. Federal agencies which maintain national scope datasets such as elevation, demography, vegetation, soils or hydrography want to deliver data at multiple levels of detail, but our nation is a big place, and generalization is computationally intensive. So the trick is to compute as few generalized versions as possible, and link them all together in one integrated database. Which turns out to be somewhat tricky. I work with water because hydrography is very sensitive to changing resolution and has the least flexible constraints: tributaries must connect at all levels of detail, and all versions of the stream channels must integrate with digital terrrain. Hydrography also tends to behave differently in different environmental conditions (arid vs. humid, flat vs. hilly, urban vs. rural). I'll show examples of how methods differ. I intend also to step back from pure methods to consider who might use these data versions, and how biases introduced by data processing might impede their intended use.