Current Research

My current research focuses on improving the understanding of how hyporheic zone processs interact with dynamic hydrologic conditions and geomorphic processes and diverse sources of nutrients and quantifying the processes at multiple scales. In particular, quantification of denitrifcation and respiration processes in the hyporheic zone is the first priority. Previous study have used field measurement and mechanistic modeling approach to quantify the role of hyporheic zone process in terms of stream and groundwater flow and their qualities. However, the scale of their study is often limited to reach scale and low order streams. In this study, we develop a process-based modeling appraoch to quantify the basin scale hyporheic zone processes in the Columiba River Basin. Detailed information can be found at the Project website.

SUMMARY OF QUALIFICATIONS

• Expertise in hydrologic science, soil science, plant physiology and water quality
• Distributed ecohydrologic modeling, sediment yield modeling, model parameterization, model evaluation and uncertainty analysis
• Watershed and stream biogeochemistry modeling
• Climate change and land use impact analysis
• Skilled in environmental data collection (including sampling design) and analysis
• GIS and remotely sensed data analysis for urban/forest management

Education

• 2015 Ph.D. in the Environmental Science and Management at the University of California, Santa Barbara
• 2008 M.S. in the Geography at the Buffalo University
• 2006 M.S. in the Environmental System Engineering at the University of Western Australia
• 2003 B.SE. in the Environmental Engineering at the Pusan National University

Employment History

• 2019-Current Earth Scientist at the PNNL
• 2019-2019 Postdoctoral Research Fellow at the Lehigh University
• 2015-2019 Postdoctoral Research Fellow at the Research Foundation of CUNY and NYC DEP
• 2005-2007 Research Hydrologist at the Korea Institute of Water and Environment

Publications

JOURNAL PAPERS In Preparation

• Accuracy assessment of models for predicting multi-scale spatial and temporal soil moisture using multiple methods
• Effect of forest harvesting and recovery on streamflow and stream dissolved organic carbon and nitrate in Neversink Reservoir streams
• Experimental investigation of the effects of vegetation on morphodynamics and sediment sorting processes in a large scale outdoor laboratory
• Stream nitrate in relation to atmospheric nitrogen sources, catchment hydrologic dynamics, and connectivity in the Catskill Mountain
• Comparative study in detecting the impact of watershed management and climate variability on water quality trends in New York City water supply watersheds
• Key controls on spatial and temporal variability of dissolved organic carbon in Neversink River basin
• Comparison of RHESSys and SWAT for predicting hydrologic conditions in two small watersheds, Catskill mountain regions
• K. Son and Tague, C Importance of soil parameter uncertainty in assessing climate change projections in small two Sierra Nevada watersheds
• CL, Jang, J. Nelson, K. Son, Y. Shimizu, Numerical simulation of effects of varying sediment supply on braided river morphology

PUBLISHED JOURNAL PAPERS

• Danczak, R.E., Garayburu-Caruso, V.A., Renteria, L., McKever, S.A., Otenburg, O.C., Grieger, S.R., Son, K., Kaufman, M.H., Fulton, S.G., Roebuck, J.A. and Myers-Pigg, A.N., 2023. Riverine organic matter functional diversity increases with catchment size. Frontiers in Water, 5, p.1087108.
• Son, K., Fang, Y., Gomez‐Velez, J.D., Byun, K. and Chen, X., 2022. Combined Effects of Stream Hydrology and Land Use on Basin‐Scale Hyporheic Zone Denitrification in the Columbia River Basin. Water Resources Research, 58(12), p.e2021WR031131.
• Mudunuru, M.K., Son, K., Jiang, P., Hammond, G. and Chen, X., 2022. Scalable deep learning for watershed model calibration. Frontiers in Earth Science, 10, p.1026479.
• Son, K., Fang, Y., Gomez‐Velez, J.D. and Chen, X., 2022. Spatial microbial respiration variations in the hyporheic zones within the Columbia River Basin. Journal of Geophysical Research: Biogeosciences, 127(11), p.e2021JG006654.
• Jiang, P., Son, K., Mudunuru, M.K. and Chen, X., 2022. Using mutual information for global sensitivity analysis on watershed modeling. Water Resources Research, 58(10), p.e2022WR032932.
• Hung, F., Son, K. and Yang, Y.E., 2022. Investigating uncertainties in human adaptation and their impacts on water scarcity in the Colorado river Basin, United States. Journal of Hydrology, 612, p.128015.
• Chen, X., Lee, R.M., Dwivedi, D., Son, K., Fang, Y., Zhang, X., Graham, E., Stegen, J., Fisher, J.B., Moulton, D. and Scheibe, T.D., 2021. Integrating field observations and process-based modeling to predict watershed water quality under environmental perturbations. Journal ofHydrology, 602, p.125762.
• Yang, Y.E., Son, K., Hung, F. and Tidwell, V., 2020. Impact of climate change on adaptive management decisions in the face of water scarcity. Journal of Hydrology, p.125015
• Contosta, A.R., Casson, N.J., Garlick, S., Nelson, S.J., Ayres, M.P., Burakowski, E.A., Campbell, J., Creed, I., Eimers, C., Evans, C. and Fernandez, I., 2019. Northern forest winters have lost cold, snowy conditions that are important for ecosystems and human communities. Ecological Applications, 29(7), p.e01974
• Son, K., Lin, L., Band, L. and Owens, E.M., 2019. Modelling the interaction of climate, forest ecosystem, and hydrology to estimate catchment dissolved organic carbon export. Hydrological Processes, 33(10), pp.1448-1464.
• Son, K. and Tague, C., 2019. A top–down soil moisture and sap flux sampling design of a rain–snow transition mountain watershed. Hydrological Processes, 33(11), pp.1553-1568.
• Son, K. and Tague, C. Effect of climate warming on ecohydrologic fluxes of two Sierra Nevada watersheds, Ecohydrology ; 10.1002/eco.2053
• Son, K., Tague. C and Hunsaker, C.T Effects of Model Spatial Resolution on Ecohydrologic Predictions and Their Sensitivity to Inter-Annual Climate Variability, Water 2016, 8, 321; doi:10.3390/w8080321
• Kim, J., Noh, J., Son, K. and Kim, I., 2012. Impacts of GIS data quality on determination of runoff and suspended sediments in the Imha watershed in Korea. Geosciences Journal, 16(2), pp.181-192.
• J. Kim, K. Son, J. Noh and S. Lee. Estimation of Suspended Sediment Load in Imha- Andong Watershed using SWAT Model, J. of KSEE / Vol. 30, No. 12, 2008.
• Son, K., and Kim, J., Application of Proxy-basin Differential Split-Sampling and Blind- Validation Tests for Evaluating Hydrological Impact of Climate change Using SWAT, Journal of KWRA, Vol. 41, No. 10, 969-982, 2008. 10.
• K. Son and M. Sivapalan. Improving model structure and reducing parameter uncertainty in conceptual water balance models through the use of auxiliary data, Water Resources Research, VOL. 43, W01415, doi: 10.1029/2006WR005032, 2007.
• Kim, J.K., Son, K.H., Noh, J.W., Jang, C.L. and Ko, I.H., 2006. Multi-variable and Multi-site Calibration and Validation of SWAT for the Gap River Catchment. Journal of Korea Water Resources Association, 39(10), pp.867-880.
• Kim, J.K., Son, K.H., Noh, J.W., Jang, C.L. and Ko, I.H., 2006. Evaluation of urbanization effect and analysis of hydrological characteristics in the Gap River catchment using SWAT. Journal of Korea Water Resources Association, 39(10), pp.881-890.