Watershed Resilience to Climate Change: Hysteresis behaviors of Discharge-Turbidity Concentration Relationship
Start Date
February 2018
End Date
February 2018
Abstract
Understanding urban watershed resilience to climate change and variability in the Clackamas River Basin (CRB) can aid stakeholders in managing stormwater and sanitary sewer treatment facilities to provide high-quality drinking water and watershed services. Changing precipitation regimes are likely to affect the relationship between discharge and water quality in the CRB. We examined the dominant hysteresis patterns of the discharge-turbidity relationship after major storm events in three nested watersheds using statistical analysis by season. By using available high-resolution discharge and turbidity data, we quantified hysteresis relation between discharge and water quality parameters by Hysteresis Index (HI) and classified hysteresis loops to examine HI variability to seasons, storm intensity, soil type, and land use. This paper uses five years of high-resolution water quantity and quality parameter data (2012-2016) from three monitoring stations in CRB to observe hysteresis behaviors. Watershed characteristics such as land cover type, hydrologic soil group, and drainage area were identified as potential factors that explain HI patterns. Furthermore, water quantity and quality parameters were analyzed using multiple linear regression models and correlation matrix. Results show that the maximum discharge, discharge range, and turbidity range correlates with hysteresis patterns while storm intensity moderately correlates with hysteresis behaviors. The empirical results from this research serves as an observational baseline for model evaluation and future projections in hydroclimate and water quality. A deeper understanding of discharge-concentration relationship can yield knowledge to stakeholders seeking effective ways to increase resilience of watershed services to climate change in the CRB.
Subjects
Water quality, Climate Change, Hydrology
Persistent Identifier
https://archives.pdx.edu/ds/psu/25624
Watershed Resilience to Climate Change: Hysteresis behaviors of Discharge-Turbidity Concentration Relationship
Understanding urban watershed resilience to climate change and variability in the Clackamas River Basin (CRB) can aid stakeholders in managing stormwater and sanitary sewer treatment facilities to provide high-quality drinking water and watershed services. Changing precipitation regimes are likely to affect the relationship between discharge and water quality in the CRB. We examined the dominant hysteresis patterns of the discharge-turbidity relationship after major storm events in three nested watersheds using statistical analysis by season. By using available high-resolution discharge and turbidity data, we quantified hysteresis relation between discharge and water quality parameters by Hysteresis Index (HI) and classified hysteresis loops to examine HI variability to seasons, storm intensity, soil type, and land use. This paper uses five years of high-resolution water quantity and quality parameter data (2012-2016) from three monitoring stations in CRB to observe hysteresis behaviors. Watershed characteristics such as land cover type, hydrologic soil group, and drainage area were identified as potential factors that explain HI patterns. Furthermore, water quantity and quality parameters were analyzed using multiple linear regression models and correlation matrix. Results show that the maximum discharge, discharge range, and turbidity range correlates with hysteresis patterns while storm intensity moderately correlates with hysteresis behaviors. The empirical results from this research serves as an observational baseline for model evaluation and future projections in hydroclimate and water quality. A deeper understanding of discharge-concentration relationship can yield knowledge to stakeholders seeking effective ways to increase resilience of watershed services to climate change in the CRB.
