Hydrology and Water Resources

Our research group has been examining various aspects of hydrology and water resource topics in both urban and rural settings in different parts of the world. In the Pacific Northwest, in collaboration with many local, regional agencies (e.g., US Geological Survey, Oregon Transportation Research and Education Consortium, Metro, City of Portland, Portland Water Bureau, Tualatin River Valley Water District, Clakamas River Water Providers, City of Hillsboro, Clean Water Services, and Watershed Councils), we have been examining such topics as water quality and land cover change (Tualatin and Johnson Creek), the effects of climate change on watershed hydrology and transportation infrastrcture (Portland metro area), economic impacts of climate change on freshwater resources (Willamette River basin), interactions among climate variability, hydrologic ecosystem services in a chagning climate (Sandy River, Northern Willamette Valley), land use and residential water consumption (Portland, Hillsboro, Clackamas), climate change and water demand modeling (Portland metro), urban stream restoration (Johnson Creek), and the effects of urban storm water runoff on water quality (Fanno Creek). In Korea, in collaboration with Sejong University and Meteorological Research Institute of Korea, we have examined vulnerability of flood risks (Gangwon Province) and the interactions of water use, climate, and population changes (Seoul and Han River basin). Research projects have been funded by US National Science Foundation, National Oceanic and Atmospheric Administration, US Enviornmental Protection Agency, US Geological Survey, Oregon Transportation Research and Education Consortium, Ministry of Education, Science and Technology of Korea, and James F. and Marion L. Miller Foundation. We are using various biophysical and socioeconomic data describing watershed characteristics to investigate the complex and hierarchical interactions of watershed dynamics. We are also using both quantitative and qualitative methods to unravel these complex interactions. Geographic information systems and spatial statistics are strongly recommended topics for all students working in this area. Students are also encouraged to take related courses offered by other departments, including the Civil and Environmental Engineering and Environmental Sciences and Management departments.

Current research projects

1. NSF Geography and Spatial Sciences, Analyzing the Effects of Spatial Autocorrelation in Geospatial Databases (co-PI. Total $336,478, PSU portion $126,700) (2016-2019)

2. NSF UrbanSRN: Urban Resilience to Extreme Weather Related Events Sustainability Research Network https://sustainability.asu.edu/urbanresilience/(2015-2020) (senior personnel. Total 12 M, PSU portion $831K)

3. PSU/City of Portland BPS, Climate Change and Flood Risk inPortland: Toward Flood Resilient City, PI, 99,678 (2015-2017)

4. NSF IGERT: Sustaining Ecosystem Services to Support Rapidly Urbanizing Areas, co-PI, $2,998,983 (2010-2017)

5. NSF GEO/Climate Research Investment, Collaborative Research WSC Category 2: Anticipating water scarcity and informing integrative water system response in the Pacific Northwest, project website, co-PI, $4.3 million (total), $325,309 (PSU portion), 2010-2016

Past representative projects

6.NSF, ULTRA-Ex: Collaborative Research: How Do Feedbacks Between Governance and Biophysical Systems Affect the Resilience of Urban Socioecological Systems?  project website, co-PI, $300,000 (total), $184,416 (PSU portion), 2010-2016

7. NSF Geography and Spatial Sciences Program, Collaborative Research: Spatial Analysis of Ecosystem Service Shifts Caused by Climate Change and Land Conversion in the Metropolitan Fringe, Project website, Lead PI, $350,000 (total), $222,021 (PSU portion), 2010-2016

8. NSF CCLI, Interactive Teaching Materials for Understanding Ecological Response from Climate Change in Urban Forests (co-PI, 174,962) 2009-2013.

9. NOAA-SARP, Integrated Water and Land Planning as a Climate Adaptation Strategy: Comparisons of Portland, Oregon and Phoenix, Arizona, Lead PI, $299,996

10. US Army Corp of Engineers, Integrated water resource management across North American River basins, PI, $25,000

11. US Geological Survey, Envisioning future changes in climate and hydrology in Northwest estuaries, PI, $15,829

12. James F. and Marion L. Miller Foundation, Moving Forward: Adaptation and Resilience to climate change and land development through integrative river basin modeling and management PI, $73,451

People	Publications	Presentations

Faculty contact: Heejun Chang ( mailto:changh@pdx.edu) Department of Geography

Postdoctotal scholar

Ilwon Jung (Ph.D. Sejong University) Ilwon has worked on climate change impact assessments for large river basins in Korea and Oregon. He has used a number of statistical methods and numerical models to understand the dynamics of complex water systems in a changing climate. He won the best dissertation award from the Korean Water Resources Association. Ilwon is currently a research scientist in Climate Research Department at APEC Climate Center in South Korea, a research center that seeks to strengthen scientific and technological cooperation across the Asia Pacific Region to effectively deal with the consequences of climate related hazards.

Current students

Jeff Ramsey (MS Candidate, entered fall 2012) Jeff is currently working on ecosystem services provided by urban trees in Portland (currently work for City of Portland)

Zack Herzfeld (MS Candidate, entered fall 2013) Zack is currently working on the effectiveness of stream restoration on ecosystem service provision in Mexico

Ryan Bonnette (MS Candidate, entered fall 2014) Ryan is currently working on the determinants of urban water use across scales in Portland.

Harvey Hembree (MS Candidate, entered fall 2014) Harvey is currently working on spatial analysis of watershed ecosystem services in the Tualatin River basin

Alex Nagel (MS candidate, entered fall 2015)

Alexis Cooley (MS candidate, entered fall 2015)

Zbigniew Grabowski (PhD Candidate, entered fall 2012) Z is a ESUR-IGERT fellow (co-advised by Elise Granek at ESM) interested in the coupled linkage between terrestrial and marine ecosystem services and management.

Daniel Larson (PhD Candidate, entered fall 2014) Daniel is a ESUR-IGERT fellow interested in watershed ecosystem services in urbanizing basins using sociohydrological framework.

Hue Doung (PhD Candidate, entered fall 2014) Hue is interested in vulnereability of community to urban floods in Vietnam

Former Students

David examined the effects of climate change in the upper Clackamas River basin (near Portland ). The findings of his research agreed with other regional models of climate change, which anticipate that Cascades watersheds at moderate elevations are susceptible to losing a large proportion of their snowpack if temperature increases do occur during the 21 st century. This effect will likely lead to increases to winter flows, and decreases to summer flows from these watersheds. David is interested in the use of GIS and statistical analysis for waterresources assessment and management. David is currently working for Columbia River Inter-Tribal Fish Commission in Portland, OR.

Mike investigated trends in oxygen demand variables (DO sat, COD, TKN, NH 3 -N) from 1993-2003 for thirteen water quality monitoring sites throughout the Rock Creek watershed. A multi-scale land cover change analysis, through aerial photo interpretation, and a local analysis of urban land cover variables provided insight into the relationship of human influence on the landscape and water quality characteristics for this watershed. Mike is currently working for Portland State University in Portland, OR.

Alex examined changes in channel morphology after effective discharge events for reference and impaired reaches of Kelley Creek, a tributary of Johnson Creek in east Portland. Examined parameters include longitudinal profiles, cross-sections, and pebble counts. He measured how channel geometry, residual pool dimensions, and particle size distribution changed following the events. The effective discharge flows altered the restoration reach more substantially than the reference reaches. This study has implications for restoration planners with the dynamic fluvial geomorphology of stream channels in humid temperate climates. Alex is currently working for Pacific Northwest National Laboratory in Richland, WA.

Jon investigated the effects of climate change and urban development on runoff in Rock Creek, Oregon, one of the fastest growing urban areas in the State. Using a BASIN-SWAT model, he identified the importance of scale in detecting changes in runoff in the basin. He is also interested in integrated water resource management, GIS, and water quality issues. Jon has worked as a research assistant for Heejun Chang, and has several coauthored publications from the funded research projects. Jon is currelty working for Quantum Spatial in Portland, OR..

Joe Parker examined the dynamic situation for village water managers in a rural area of Sichuan province, China. His interest is in identifying specific problems in local irrigation water management that are largely the result of government policies and programs meant to stabilize food production and costs (keeping rice prices at WTO-mandated levels), but which in fact are undermining ancient culturally-driven, eminently sustainable practices. A recent paper by Joe, Forestalling Water Wars: Returning to Our (Grass) Roots deals with the subject of conflict over water rights.

Sarah investigated the combined effects of climate change and urban development on water quality in the Tualatin River basin and its sub-basins. She uses a Climate Assessment Tool in BASIN-HSPF to model potential changes in sediments, nitrogen and phosphorus loads as well as runoff at multiple spatial and temporal scales. Sarah has been working for a Miller grant on sustainable water resource management and a Korean project that investigates adaptive water resource management under climate change. She is currently a doctoral student at the University of Oregon. Sarah started her tenure-track job at the University of Alabama in August 2014.

Lily investigated the spatial dimensions of water supply and demand for sustainable water resource management under climate change and population growth in a suburban city. Lily worked for a Miller Foundation grant examining the relation between climate varibility, vegetation patterns and water demand in the Portland metro area. She also worked for simulating microclimatology using the LUMPS model as part of a NOAA project. Lily is currently pursuing her doctoral degree in the School of Geography and Development at the University of Arizona.

James Monzione (MS, Spring 2011) Urban stromwater management in Portland, Oregon (Now works for US Army Corp of Engineers)

Bethany Pratt (MS, Summer 2011) Effects of land cover, topography, and built structure on seasonal water qualilty at multiple spatial scales

Cale Garrett (MS, Spring 2012) Evalaution of streamflow restoration efforts by Water Trusts in Oregon (Now works for Portland Energy Conservation, Inc.)

Matt Wood (MS, Summer 2012) Streamflow analysis and a comparison of hydrologic metrics in urban streams (Now works for ICF International)

Madeline Steele (MS, Winter 2013) Effects of HRU size on PRMS performance in 30 western US basins (Now works for US Fisheries and Wildlife Services)

Willow Campbell (MS, Summer 2013) Spatial analysis of climate and winegrape production in winegrape growing regions of Oregon, United States of America

Wes Hoyer (MS, Fall 2013) Scenario development and analysis of freshwater ecosystem services under land cover and climate change in the Tualatin and Yamhill River basins, Oregon. (Now works for Portland State University)

Betsy Breyer (MS, Winter 2014) Household water demand and neighborhood context: A multi-level approach (Now a PhD student at the University of Illinois)

Mike Psaris (MS, Spring 2014) Assessing hydrogic and water quality sensitivities to precipitation changes, urban growth, and land management using SWAT (Now works for CleaRESULT)

Eric Watson (MS, Summer 2016) Use of distance weighted metrics to investigate landscape-stream temperature relationships

Publications (* student author)

Chang, H. (2017) Water and Climate Change, In The International Encyclopedia of Geography, Wiley (forthcoming)

Chang, H. (2017) Water Conservation, In The International Encyclopedia of Geography, Wiley (forthcoming)

Chang, H., Watson, E.*, Strecker, A., (2016) Climate change and stream temperature in the Willamette River basin: Implications for fish habitat, World Scientific Series on Asia-Pacific Weather and Climate (forthcoming)

Turner, D.P., Conklin, D.R., Vache, K., Schwartz, C., Nolin, A.W., Chang, H., Watson, E.*, Bolte, J.P.  (2016) Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance in Western Oregon Ecohydrology

Crow-Miller, B., Chang, H., Stoker, P., and Wentz, E. (2016) Facilitating collaborative urban water management through university-utility cooperation, Sustainable Cities and Society

Sangaralingam, A., Guan, M, Sleigh, A., Wright, N. and Chang, H., (2016) The Influence of Floodplain Restoration on Sediment Dynamics in an Urban River, Journal of Flood Risk Management

Parandvash, H. and Chang, H. (2016) Analysis of Long-Term Climate Change on per Capita Water Demand in Urban Versus Suburban Areas in the Portland metropolitan area, USA. Journal of Hydrology 538: 574-586.

Straus, J.*, Chang, H., and Hong, C-Y.* (2016) An Exploratory Path Analysis of Attitudes, Behaviors and Summer Water Consumption in the Portland Metropolitan Area, Sustainable Cities and Society 23: 68-77

Grabowski, Z.*, Watson, E.*, and Chang, H. (2016) Using spatially explicit indicators to investigate watershed characteristics and stream temperature relationships, Science of the Total Environment 551-552: 376-386.

Shandas, V., Lehman, R., Larson, K., Bunn, J., Chang, H. (2015) Stressors and Strategies for Managing Urban Water Scarcity: Perspectives from the Field, Water 7(12), 6775-6787.

Lee, S., Chang, H., and Gober, P. (2015) Space and time dynamics of urban water demand in Portland, Oregon and Phoenix, Arizona, Stochastic Environmental Research & Risk Assessment 29: 1135-1147.

Yeakley, J.A., Ervin, D., Chang H., Granek, E, Dujon, V., Shandas, V., and Brown, D. (2015) Ecosystem services of streams and rivers.  In River Science, Wiley, UK.

Kang, H., Chang, H., (2015) Chapter 14: Rapid land use changes and ecosystem services shift in coastal areas: A case study of Korea in Water Ecosystem Services: A Global Perspective, Cambridge University Press. pp. 119-128.

Shandas, V, Yeakley, J.A., Granek, E., Ervin, D., Dujon, V., Chang, H. (2014) Chapter 14: Characterizing Urban Ecosystem Services: Integrating the biophysical and social dimensions of human dominated landscapes, pp. 295-312. In KN Ninan, Valuing Ecosystem Services—Methodological Issues and Case Studies, Edward Elgar Press

Hoyer, W,* and Chang, H. (2014) Assessment of freshwater ecosystem services in the Tualatin and Yamhill basins under climate change and urbanization. Applied Geography 53: 402-416

Hong, C.* and Chang, H. (2014) Uncovering the influence of household sociodemographic and behavioral characteristics on summer water consumption in the Portland metropolitan area. International Journal of Geospatial and Environmental Research 1(2) Article 2 http://dc.uwm.edu/ijger/vol1/iss2/2/

Psaris, M.* and Chang, H. (2014) Assessing the impacts of climate change, urbanization, and filter strips on water quality using SWAT, International Journal of Geospatial and Environmental Research 1(2) Article 1 http://dc.uwm.edu/ijger/vol1/iss2/1/

Chen, H.* and Chang, H. (2014) Response of Discharge, TSS, and E.coli to Rainfall Events in Urban, Suburban, and Rural Watersheds. Environmental Science: Processes and Impacts 16 (10): 2313 – 2324 DOI: 10.1039/C4EM00327F

Sonia, S.* and Chang, H. (2014) Effects of land cover change on water quality in urbanizing streams at two spatial scales. International Journal of Geospatial and Environmental Research 1, 1 Article 8 http://dc.uwm.edu/ijger/vol1/iss1/8/

Chang, H. Praskievicz, S.*, and Parandvash, H. (2014) Sensitivity of urban water consumption to weather climate variability at multiple temporal scales: The case of Portland. International Journal of Geospatial and Environmental Research, 1, 1, Article 7 http://dc.uwm.edu/ijger/vol1/iss1/7/

Breyer, B.* and Chang, H. (2014) Urban water consumption and weather variation in the Portland, Oregon metropolitan area, Urban Climate 9:1-18.

Netusil, N., Kincaid, M.* and Chang, H. (2014) Valuing water quality in urban watersheds: a comparative analysis of Johnson Creek, Oregon and Burnt Bridge Creek, Washington. Water Resources Research 50(5): 4254-4268.

Hoyer, W.*, Chang, H. (2014) Development of Future Land Cover Change Scenarios in the Metropolitan Fringe, Oregon, U.S., with Stakeholder Involvement. Land 3(1):322-341.

Chang, H., Thiers, P., Netsuil, N. R., Yeakley, A., Rollwagen-Bolen, G., Bolen, S., Singh, S*. (2014) Relationships between environmental governance and water quality in growing metropolitan areas: A synthetic view through the coupled natural and human system lens. Hydrology and Earth System Sciences 18: 1383-1395.

Chang, H., Johnson, G.*, and Hickey, T.*, and Jung, I. W. (2014) Spatial analysis of annual runoff ratios and their variability in contiguous US. Journal of Hydrology 511: 387-402.

Browning-Aiken, A. and Chang, H. (eds) (2014) Science and Practice of integrated river basin management: Lessons from North and Central American UNESCO-HELP basins US Geological Survey

Tripathi, R.*, Patra, A.*, Sengupta, S. K.*, Chang, H., Jung, I-W. (2014) Climate change, urban development, and community perception of an extreme flood: A case study of Vernonia, Applied Geography 46:137-146.

Dresner, M., de Rivera, C., Fuccillo, K.*, Chang, H. (2014) Improving higher order thinking and knowledge retention in a lower division environmental science course sequence. BioScience 64(1): 40-48.

Jung, I.W., Chang, H., and Risley, J. (2013) Effects of runoff sensitivity and catchment characteristics on regional actual evapotranpiration trends in the conterminous US, Environmental Research Letters 8, 044002.

Chang, H., and Psaris, M.* (2013) Local landscape predictors of maximum stream temperature and thermal sensitivity in the Columbia River basin, USA. Science of the Total Environment  461-462: 587-600.

Jaeger, W.K., Plantinga, A.J., Chang, H., Grant, G., Hulse, D., McDonnell, J., Moradkani, H., Morzillo, A.T., Mote, P., Nolin, A., Santlemann, M., Wu, J. (2013) Toward a formal definition of water scarcity in natural-human systems, Water Resources Research 49(7): 4506-4517 DOI: 10.1002/wrcr.20249

Larson, K., Polsky, C., Gober, P., Chang, H., and Shandas, V. (2013) Vulnerability of water systems to the effects of climate change and urbanization: A comparison of Phoenix, Arizona and Portland, Oregon (USA), Environmental Management 52(1): 179-195.

Steele, M.*, Chang, H., Reusser, D.A., Brown, C.A. and Jung, I.W.(2013) Potential climate-induced runoff changes and associated uncertainty in four Pacific Northwest Estuaries US Geological Survey Open-File Report: 2012-1274

Chang, H., Jung, I., Strecker, A., Wise, D., Lafrenz, M., Shandas, V., Moradkhani, H., Yeakley A., Pan, Y., Bean, R.*, Johnson, G.*, Psaris M.* (2013) Water Supply, Demand, and Quality Indicators of the Spatial Distribution of Water Resources Vulnerability in the Columbia River Basin, USA. Atmosphere-Ocean 51(4): 339-356.

Waibel, S.*, Gannett, M., Chang, H., and Hulbe, C. (2013) Spatial variability of the response to climate change in regional groundwater Systems – Examples from Simulations in the Deschutes Basin, Oregon, Journal of Hydrology 486: 187-201.

Jung, I-W., Chang, H. and Bae, D-H. (2013) Spatially-explicit flood risk assessment caused by climate change in South Korea, KSCE Journal of Civil Engineering 17(1): 233-243.

Gober, P., Larson, K. Quay, R., Polsky, C., Chang, H., Shandas, V. (2013) Why land planners and water managers don’t talk to one another and why they should!, Society and Natural Resources 26(3): 356-364.

Betsy, B.*, Chang, H., and Parandvash, H. (2012) Land-use, temperature and single family residential water use patterns in Portland, Oregon and Phoenix, Arizona, Applied Geography 35: 142-151

Surfleet, C., Tullos, D., Chang, H., Jung, I-W., (2012) Comparison of hydrologic modeling approaches for climate change assessment and water resources decision making. Journal of Hydrology464/465: 233-248.

Chang, H., and House-Peters, L.* (2012) Climate Change in The US-South Korea Alliance: Meeting New Security Challenges edited by Scott Snyder. Lynne Rienner Publishers: Boulder, CA. pp.145-172.

Gober, P., Middel, A, Brazel, A., Myint, S., Chang, H., Duh, J.D., House-Peters, L.* (2012) Tradeoffs between water conservation and temperature amelioration in Phoenix and Portland: Implications for urban sustainability, Urban Geography 33(7): 1030-1054.  

Chang, H., Jung, I-W., Steele, M.*, Garnett, M. (2012) Spatial Patterns of March and September streamflow trends in Pacific Northwest Streams. Geographical Analysis 44(3): 177-201.

Pratt, B.* and Chang, H. (2012) Effects of Land Cover, Topography, and Built Structure on Seasonal Water Quality at Multiple Spatial Scales, Journal of Hazardous Materials 209/210: 48-58.

Ervin, D., Brown, D., Chang, H., Dujon, V., Granek, E., Shandas, V., and Yeakley, A. (2011) Managing ecosystem services supporting urbanizing areas, Solutions 2(6): 74-86.

Jung, I-W. and Chang, H. (2011), Climate change impacts on spatial patterns in drought risk in the Willamette River Basin, Oregon, USA, Theoretical and Applied Climatology 108(3-4): 355-371.

House-Peters, L.* and Chang, H. (2011) Modeling the Impact of Land Use and Climate Change on Neighborhood-scale Evaporation and Nighttime Cooling: A Surface Energy Balance Approach, Landscape and Urban Planning 103:139-155 (cited in European Commission's Science for Environmental Policy)

Middel, A, Brazel, A., Gober, P., Myint, S., Chang, H., and Duh, J.D. (2011) Land Cover, Climate, and the Summer Surface Energy Balance in Phoenix, AZ and Portland, OR, International Journal of Climatology 32: 2020-2032 DOI: 10.1002/joc.2408

Chang, H. and Lawler, K.* (2011) Impacts of climate variability and change on water temperature in an urbanizing Oregon basin. In Water Quality: Current Trends and Expected Climate Change Impacts, IAHS Publication 348: 123-128

House-Peters, L.* and Chang, H. (2011) Urban water demand modeling: Review of concepts, methods, and organizing principles, Water Resources Research 47 W05401

Costanza R, Kubiszewski I, Ervin D, Bluffstone R, Boyd J, Brown D, Chang H, Dujon V, Granek E, Polasky S, Shandas V, Yeakley, A. (2011) Valuing ecological systems and services. F1000 Biol Rep 2011, 3:14

Praskievicz, S.* and Chang, H. (2011) Impacts of climate change and urban development on water resources in the Tualatin River basin, Oregon. Annals of the Association of American Geographers 101(2): 249-271.

Jung, I.-W., Chang, H. and Moradkhani, H. (2011) Quantifying uncertainty in urban flooding analysis considering hydroclimatic projection and urban development effects, Hydrology and Earth System Sciences 15(2): 617-633.

Jung, I-W. and Chang, H. (2011) Assessment of future runoff trends under multiple climate change scenarios in the Willamette River Basin, Oregon, USA, Hydrological Processes 25(2): 258-277.

Chang, H., Jones, J.,Gannett, M.,Tullos, D., Moradkhani, H., Vache, K., Parandvash, H., Shandas, V., Nolin, A., Fountain, A.,  Johnson, S., Jung, I.-W. House-Peters, L.*, Steele, M.* and Copeland, B.* (2010) Chapter 3: Climate change and freshwater resources in Oregon, in Oregon Climate Assessment Report K.D. Dello and P.W. Mote (eds). College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR. pp. 69-150.

Jung, I.W., Chang, H., and Bae, D.-H. (2010) Climate elasticity of Korean Water Resources, Journal of the Korean Water Resources Association, 43(10): 851-864.

Chang, H. and Jung, I-W. (2010) Spatial and temporal changes in runoff caused by climate change in a complex large river basin in Oregon. Journal of Hydrology 388 (3-4): 186-207 (top 25 hottest article in Earth and Planetary Sciences)

Chang, H. Lafrenz, M. Jung, I-W., Figliozzi, M., Platman, D. and Pederson, C. (2010) Potential impacts of climate change on flood-induced travel disruption: A case study of Portland in Oregon, USA. Annals of the Association of American Geographers 100(4): 938-952

Chang, H. House-Peters, L.* (2010) Cities as place for climate mitigation and adaptation: A case study of Portland, Oregon, USA, Journal of the Korean Geographical Society 45 (1): 49-74.

Chang, H. Parandvash, H. and Shandas, V. (2010) Spatial variartions of single family residential water consumption in Portland, Oregon. Urban Geography 31(7): 953-972.

House-Peters, L,* Pratt, B*. and Chang, H. (2010) Effects of urban spatial structure, sociodemographics, and climate on residential water consumption in Hillsboro, Oregon, Journal of the American Water Resources Association 46(3): 461-472.

Im, E-S, Jung, I-W., Chang, H., Bae, D-H., Kwon, W-T. (2010) Hydroclimatological Response to Dynamically Downscaled Climate Change Simulations for Korean Basins. Climatic Change 100: 485-508

Praskievicz, S,* and Chang, H. (2009) A review of hydrologic modeling of basin-scale climate change and urban development impacts, Progress in Physical Geography 33(5): 650-671.

Praskievicz, S.*, and Chang, H. (2009) Identifying the relationships between urban water consumption and weather variables in Seoul, Korea. Physical Geography 30(4): 308-323.

Praskievcz, S.*, and Chang, H. (2009) Winter precipitation intensity and ENSO/PDO variability in the Willamette Valley of Oregon. International Journal of Climatology 29(13): 2033-2039.

Franczyk, J.,* and Chang, H. (2009) The effects of climate change and urbanization on the runoff of the Rock Creek in the Portland metropolitan area, Oregon, USA. Hydrological Processes 23(6): 805-815 (Editor's choice of top articles)

Franczyk, J.,* and Chang, H. (2009) Spatial analysis of water use in Oregon, USA, 1985-2005. Water Resources Management 23(4): 755-774

Chang, H., Franczyk, J.,* and Kim, C (2009) What is responsible for increasing flood risks? The case of Gangwon province, Korea. Natural Hazards 48(3): 339-354

Chang, H. (2008) Teaching water sustainability through visuals and student-based learning. Oregon English Journal 30(2): 48-51.

Duh, J., Shandas, V., Chang, H., and George, L. (2008) Rates of urbanization and the resilience of air and water quality. Science of the Total Environment 400 (1-3): 238-256  

Chang, H. and Franczyk, J.* (2008) Climate change, land use change, and floods: Toward an integrated assessment. Geography Compass 2(5): 1549-1579: doi: 10.1111/j.1749-8198.2008.00136.x (featured article in Hydrology and Water Resources)

Bae, D-H, Jung, I-W., and Chang, H. (2008) Long-term trend of precipitation and runoff in Korean river basins. Hydrological Processes 22(14): 2644-2656

Chang, H. (2008) Spatial analysis of water quality trends in the Han River basin, South Korea. Water Research 42: 3285-3304  

Boeder, M.* and Chang, H. (2008) Multi-scale analysis of oxygen demand trends in an urbanizing Oregon watershed. Journal of Environmental Management 87(4): 567-581.

Levell, A.* and Chang, H.(2008) Monitoring the Channel Process of a Stream Restoration Project in an Urbanizing Watershed: A Case Study of Kelley Creek, Oregon, USA River Research and Applications 24(2): 169-182.

Bae, D-H. Jung, I-W., and Chang, H. (2007) Regional impacts of climate change on water resources in Korea by using a high resolution scenario. Climate Research 35(3): 213-226.

Franczyk, J.* and Chang, H. (2007) Economic impacts of climate change on water resources: Toward spatially-explicit impact assessments. The Geographical Journal of Korea 41(4): 1-12.

Chang, H., J. Franczyk*, I-S Im, W-T. Kwon, D-H. Bae, and I-W. Jung (2007) Vulnerability of Korean water resources to climate change and population growth. Water Science and Technology 56(4): 57-62.

Chang, H. and Kwon, W-T. (2007) Spatial patterns of summer precipitation trends in South Korea, 1973-2005 Environmental Research Letters 2 045012 doi:10.1088/1748-9326/2/4/045012

Knight, C. G., B. M. Evans, J. M. Hamlett, D.W. Lehning, M. P. Staneva, J. J. Carmichael T. N. Hristov, D. Dimitrov, V. D. Ioncheva, I. I. Nikolov, and H. Chang (2007) REKA: A Catchment Management Tool for Improving Water Quality. pp.129-138 In "Managing Water Resources in a Changing Physical and Social Environment" edited by Robinson, P.J., Jones, T., and Woo, M-K. International Geographical Union Home of Geography Publication Series, Societ? Geografica Italiana, Rome, 177pp. ISBN 978-88-88692-35-7.

Chang, H., Franczyk, J.*, Bae, D-H, Jung, I-W. Im, E-S., and Kwon, W-T. (2007) Effects of climate change and population growth on Korean water resources International Association of Hydrological Sciences 315.

Chang, H. (2007) Streamflow characteristics in urbanizing basins in the Portland Metropolitan Area, Oregon, USA, Hydrological Processes 21(2): 211-222 (DOI: 10.1002/hyp6233)

Graves, D.* and Chang, H. (2007) Hydrologic impacts of climate change in the Upper Clackamas basin of Oregon. Climate Research 33(2): 143-157.

Chang, H. (2006) City and Hydrology, in "Urban Geography and Urbanology" edited by Kim, I. And Park, S. Purungil Publisher. Seoul, Korea (ISBN: 89-87691-67-5). (in Korean)

Chang, H. J. Franczyk*, and D-H. Bae (2006) Putting climate change into water resource management: Adaptation efforts in the U.S. U.K., Canada, Australia, and the Netherlands. Journal of Environmental Policy 5(4): 19-50.

Chang, H. and T. N. Carlson (2005) Water Quality During Winter Storm Events in Spring Creek, Pennsylvania, USA, Hydrobiologia, 544:321-332 .

Chang, H. (2005) Spatial and Temporal Variations of Water Quality in the Han River and its Tributaries, Seoul, Korea, 1993-2002. Water, Air, and Soil Pollution, 161: 267-284 .

Chang, H. and T. N. Carlson (2004) Patterns of Nitrate and Phosphorus Transport in Central Pennsylvania Streams. The Pennsylvania Geographer . 42(2): 61-74

Chang, H. and C. Kim (2004) Recent research trends in American Geomorphology and Hydrogeography, Journal of the Korean Geographical Society . 39(6): 873-887

Chang, H. (2004) Water Quality Impacts of Climate and Land Use Changes in Southeastern Pennsylvania, The Professional Geographer, 56(2): 240-257.

Chang, H. (2003) Basin Hydrologic Response to Changes in Climate and Land Use: The Conestoga River Basin, Pennsylvania. Physical Geography, 24(3): 222-247.

Chang, H., C. G. Knight, M. P. Staneva, and Kostov, D. (2002) Water Resource Impacts of Climate Change in Southwestern Bulgaria . GeoJournal, 57: 115-124.

Ioncheva, V.D., J.M. Hamlett, B.M. Evans, T. N. Hristov, I. I. Nikolov, and H. Chang, (2002) Diffuse Pollution - The BISTRA model, in Knight, C.G. and Hristov, T.N. (eds.) River Environmental Knowledge and Assessment - REKA Applied to The Yantra River Basin, pp.25-55. University Park and Sofia, PA and Bulgaria (ISBN: 954-90485-3-5).

Chang, H. (2002) Spatial variations of nutrient concentrations in Pennsylvania Watersheds. Journal of the Korean Geographical Society, 37(5): 536-550

Chang, H., B. M. Evans, and D. R. Easterling. (2001) The effects of climate change on stream flow and nutrient loading. Journal of the American Water Resources Association, 37: 973-985.

Knight, C.G., H. Chang, M. Staneva, and D. Kostov. (2001) A simple basin model for simulating runoff: the Struma River GIS. The Professional Geographer, 53: 533-545.

Neff, R., H. Chang, C. G. Knight, R. Najjar, B. Yarnal and H. Walker. (2000) Impacts of climate variation and change on Mid-Atlantic region hydrology and water resources. Climate Research, 14: 207-218.