Miki Hondzo Judson W. Harvey Ben L. O’Connor 2010 <p><span>This study examined two key aspects of reactive transport modeling for stream restoration purposes: the accuracy of the nutrient spiraling and transient storage models for quantifying reach-scale nutrient uptake, and the ability to quantify transport parameters using measurements and scaling techniques in order to improve upon traditional conservative tracer fitting methods. Nitrate (NO</span>₃^&ndash;<span>) uptake rates inferred using the nutrient spiraling model underestimated the total NO</span>₃^&ndash;<span>&nbsp;mass loss by 82%, which was attributed to the exclusion of dispersion and transient storage. The transient storage model was more accurate with respect to the NO</span>₃^&ndash;<span>&nbsp;mass loss (&plusmn;20%) and also demonstrated that uptake in the main channel was more significant than in storage zones. Conservative tracer fitting was unable to produce transport parameter estimates for a riffle-pool transition of the study reach, while forward modeling of solute transport using measured/scaled transport parameters matched conservative tracer breakthrough curves for all reaches. Additionally, solute exchange between the main channel and embayment surface storage zones was quantified using first-order theory. These results demonstrate that it is vital to account for transient storage in quantifying nutrient uptake, and the continued development of measurement/scaling techniques is needed for reactive transport modeling of streams with complex hydraulic and geomorphic conditions.</span></p> application/pdf 10.1061/(ASCE)HY.1943-7900.0000180 en American Society of Civil Engineers Predictive modeling of transient storage and nutrient uptake: Implications for stream restoration article