The importance of considering shifts in seasonal changes in discharges when predicting future phosphorus loads in streams

Biogeochemistry
By: , and 

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Abstract

In this work, we hypothesize that phosphorus (P) concentrations in streams vary seasonally and with streamflow and that it is important to incorporate this variation when predicting changes in P loading associated with climate change. Our study area includes 14 watersheds with a range of land uses throughout the U.S. Great Lakes Basin. We develop annual seasonal load-discharge regression models for each watershed and apply these models with simulated discharges generated for future climate scenarios to simulate future P loading patterns for two periods: 2046–2065 and 2081–2100. We utilize output from the Coupled Model Intercomparison Project phase 3 downscaled climate change projections that are input into the Large Basin Runoff Model to generate future discharge scenarios, which are in turn used as inputs to the seasonal P load regression models. In almost all cases, the seasonal load-discharge models match observed loads better than the annual models. Results using the seasonal models show that the concurrence of nonlinearity in the load-discharge model and changes in high discharges in the spring months leads to the most significant changes in P loading for selected tributaries under future climate projections. These results emphasize the importance of using seasonal models to understand the effects of future climate change on nutrient loads.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The importance of considering shifts in seasonal changes in discharges when predicting future phosphorus loads in streams
Series title Biogeochemistry
DOI 10.1007/s10533-015-0149-5
Volume 126
Issue 1-2
Year Published 2015
Language English
Publisher Springer
Contributing office(s) Wisconsin Water Science Center
Description 20 p.
First page 153
Last page 172
Online Only (Y/N) N
Additional Online Files (Y/N) N