2nd UF Water Institute Symposium Abstract

Submitter's Name Nathan Johnson
Session Name Poster Session: Managing Water and Energy in a Transitioning Environment 2
Category Managing water and energy in a transitioning environment
Poster Number 312
Author(s) Nathan Johnson,  University of Florida
  Dr. Gregory Kiker,  University of Florida
  Model Evaluation and Climate Variability Application to the Systems Dynamic STELLA© the Apalachicola Chattahoochee Flint (ACF) Basin
  The ACF-STELLA model was created during the comprehensive study of the Apalachicola Chattahoochee Flint watershed in the mid-90’s. It was created as a shared vision model to assess the hydrologic regimes of the river under different forecasted demand datasets to determine a viable allocation strategy for the river system. However, since 1989 there has been ongoing negotiation, discussion, mandated compromise, litigation and still no permanent water management plan has been adopted. Unlike a more physical based watershed model, this model uses system dynamic processes on a STELLA© platform. Reaches have been simplified into the Chattahoochee, Flint, and Apalachicola with local inputs and grouped external inputs. The model was then overlain by human constructs and dam release logic under the Interim Operation Plan (IOP) as well as the Revised Interim Operations Plan (RIOP). Unimpaired flow datasets from 1939-2001 produced by the Army Corps of Engineers derived from original USGS datasets force the model. Evaluation techniques have been used to test the model in terms of accuracy of simulated data compared to measured flow through the use of the coefficient of determination (R2), the Nash-Sutcliffe efficiency (NSE), root mean squared error of monthly totals of daily streamflow, and graphical techniques. Moreover, drought in the southeast United States in 2006-2008 has recently brought a greater surge of attention to water management in the ACF as escalating water use conflicts intensify pressure for good policy and water distribution. Climate variability was incorporated into the ACF-STELLA model using established ENSO indicators using Wilcoxin rank sum tests and other statistical methods.