# A Shiny App for estimating Multiplier Exponent Curves from Manning’s Equation Inputs

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WASP and other flow and water quality models ask users to input multiplier and exponent values relating velocity and depth to discharge. These relationships take the form of V=aQ^b and depth=cQ^d, where the values a, b, c, and d describe the curve that approximates paired points from other sources. When paired field measurements are lacking, Manning’s equation provides an estimate of open channel flow based on channel characteristics.**AdventuresInData**, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

This app takes Manning’s equation input variables and fits nonlinear least squares parameters to estimate a, b, c, and d over 20 equal increments of depth from 0.05 meters to the user specified maximum. The computations assume a symmetrical trapezoidal channel with continuous sloped sides.

The app is available here including a link to download the code and a separate link to download a batch version of the same tool.

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