Does i-Tree use the Curve Number approach?

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Does i-Tree use the Curve Number approach?

Post by rcoville » Mon Apr 27, 2020 9:15 am

i-Tree does not use the Curve Number approach. Part of i-Tree Hydro's origin is as a process-based hydrology model alternative to Curve Number-based runoff models.

If you'd like to learn more about i-Tree's hydrology engine, with specific interest in how it differs from Curve Number and handles subsurface moisture tracking, here are some efficient options to explore:
  • Slides 14-20 of ... rology.pdf offer a solid overview. A little more detail you may find helpful continues through slides 21-31.
  • i-Tree Hydro models subsurface moisture using Topographic Index (TI) theory from TOPMODEL. Our above-ground processes are explicit and sub-surface processes are an improvement from CN, but we do simplify things a bit below ground. If you want to learn more about our use of TI theory, I recommend our Wang et al. 2008 model methods paper ( ... dology.pdf), specifically: section titled "Infiltration Into Soils", and 2nd-to-last paragraph of section titled "Overland, Impervious, and Subsurface Runoff" (in other words, first paragraph on page 81).
More resources about this are available by searching for Hydro presentations (press CTRL+F and type: Hydro) on the the i-Tree Presentations page, or reviewing our Hydro+ page's section on scientific papers.
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