Jonathan Friedman, Ph.D.
Jonathan Friedman is a hydrologist at the Fort Collins Science Center. Since joining the Fort Collins Science Center in 1993, he has devoted his career to studying interactions among riparian vegetation, river flow and channel change. Present research topics include use of riparian tree rings to reconstruct past river flow, quantification of federal reserved water rights, and determination of the effect of riparian vegetation on bank stability.
- Ph.D. Environmental, Population and Organismic Biology, University of Colorado, Boulder, 1993
- M.S. Oceanography and Limnology, University of Wisconsin, Madison, 1987
- B.S. Biology, Massachusetts Institute of Technology, 1983
- 1993-present, Hydrologist, USGS Fort Collins Science Center, Fort Collins, CO
- 1990-1993, Hydrologist, USGS Water Resources Division, Lakewood, CO
- 1988-1990, Community College Instructor, Bellevue Community College, Olympic College and Front Range Community College, Washington and Colorado.
- 1988 Assistant Natural Area Scientist, Washington Natural Heritage Program, Olympia, Washington
- Ecological Society of America
- American Geophysical Union
Science and Products
Aquatic Systems Branch scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. We then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. We also use downscaled climate projections and watershed models to predict changes in flow and tree growth resulting from human-induced climate change. We have pioneered the use of cottonwood, a dominant riparian species, for tree ring analysis; this is a significant advance in arid regions where old trees of other species are scarce. Ongoing studies focus on rivers of the Upper Missouri Basin and the Tarim River in China.
Formation of arroyos in the late 1800s greatly increased erosion across the southwestern United States. Since the 1930s, however, this erosion has decreased, partly because of bank stabilization by introduced saltcedar. With Isleta Pueblo Indian Nation, the Aquatic Systems Branch developed a new sediment dating method using saltcedar tree rings. We applied the method in a landmark study of arroyo filling along the Rio Puerco, New Mexico. We then showed how aerial application of herbicide to control saltcedar accidentally renewed erosion. This erosion may now be amplified by a beetle introduced for saltcedar control.
Riparian ecologists in the AS Branch study interactions among flow, channel change, and vegetation along rivers across the western United States and worldwide. Our work focuses on issues relevant to the management of water and public lands, including dam operation, climate change, invasive species, and ecological restoration. Investigations take place on a range of scales. For example, experimental studies in pots and growth chambers detect genetic, phenotypic, and species variations in response to environmental conditions, such as drought, frost, mycorrhizal inoculation, salinity, and carbon dioxide enrichment.
The data archive contains the aerial photographs and channel delineations used in our analysis. The images have been geo-referenced to the 1995 digital orthophoto quarter quadrangles as described by Miller and Friedman (2009). The channel delineations for all photo years (including 2003) and the delineation of the outer flood-plain boundary are stored as shapefiles.
This data release consists of sex ratio data from cottonwood trees at random points on the floodplain; tree core and tree ring data; floodplain and riparian cottonwood forest areas as shapefiles (SHP); and edges of water, channel centerline, valley bottom centerline, extent of valley bottom, and estimated bankfull channel data as shapefiles (SHP).
Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011
This study uses growth in vegetation during the monsoon season measured from LANDSAT imagery as a proxy for measured rainfall. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG) in southwestern Arizona, USA.
A long-term study of the geomorphic history of the lower Rio Puerco arroyo in north-central New Mexico included the collection of high-precision (Real-time kinematic) GPS survey data (2002, 2007, 2010, and 2014), registration and rectification of historical aerial photographs (1935, 1950s, 1970s, and 1996), aerial LiDAR survey (2005) and post-flood (2006) satellite imagery.
Population genomic analysis suggests strong influence of river network on spatial distribution of genetic variation in invasive saltcedar across the southwestern United States
Understanding the complex influences of landscape and anthropogenic elements that shape the population genetic structure of invasive species provides insight into patterns of colonization and spread. The application of landscape genomics techniques to these questions may offer detailed, previously undocumented insights into factors influencing...Lee, Soo-Rang; Jo, Yeong-Seok; Park, Chan-Ho; Friedman, Jonathan M.; Olson, Matthew S.
Model-based scenario planning to inform climate change adaptation in the Northern Great Plains—Final report
Public SummaryWe worked with managers in two focal areas to plan for the uncertain future by integrating quantitative climate change scenarios and simulation modeling into scenario planning exercises.In our central North Dakota focal area, centered on Knife River Indian Villages National Historic Site, managers are concerned about how changes in...Symstad, Amy J.; Miller, Brian W.; Friedman, Jonathan M.; Fisichelli, Nicholas A.; Ray, Andrea J.; Rowland, Erika; Schuurman, Gregor W.
A 184-year record of river meander migration from tree rings, aerial imagery, and cross sections
Channel migration is the primary mechanism of floodplain turnover in meandering rivers and is essential to the persistence of riparian ecosystems. Channel migration is driven by river flows, but short-term records cannot disentangle the effects of land use, flow diversion, past floods, and climate change. We used three data sets to quantify nearly...Schook, Derek M.; Rathburn, Sara L.; Friedman, Jonathan M.; Wolf, J. Marshall
Cottonwood management at Theodore Roosevelt National Park, North Dakota
This data release consists of the following components:Sex ratio data from cottonwood trees at random points on the floodplain in the North and South units of Theodore Roosevelt National Park, ND. These data were used to investigate the effects of age, height above, and distance from the channel on mortality of male and female trees of plains...Friedman, Jonathan M.; Griffin, Eleanor R.
Management of plains cottonwood at Theodore Roosevelt National Park, North Dakota
Establishment of cottonwood trees is driven by flood-induced channel migration, which provides the new surfaces necessary for successful germination and survival. Along the Little Missouri River the largest floods typically result from snowmelt in March or April. Seed release occurs in early summer, and seedlings usually germinate in moist, open...Friedman, Jonathan M.; Griffin, Eleanor R.
Decreased runoff response to precipitation, Little Missouri River Basin, northern Great Plains, USA
High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri...Griffin, Eleanor R.; Friedman, Jonathan M.
Contributions of moderately low flows and large floods to geomorphic change in the Rio Puerco Arroyo, New Mexico
Abstract—From the mid-1800s to around 1930, monsoonal floods incised an arroyo roughly 100 m wide and 10 m deep along the lower Rio Puerco, NM, from the confluence with the Rio San Jose downstream to the mouth at the Rio Grande, causing sedimentation and flooding downstream. Since the 1930s, the channel has greatly narrowed, a densely vegetated...Griffin, Eleanor R.; Friedman, Jonathan M.
Mean of the top ten percent of NDVI values in the Yuma Proving Ground during monsoon season, 1986-2011
This study uses growth in vegetation during the monsoon season measured from LANDSAT imagery as a proxy for measured rainfall. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG) in southwestern Arizona, USA. The LANDSAT imagery (1986-2011) was downloaded from USGS’s GlobeVis...Birtwistle, Amy N; Laituri, Melinda J.; Bledsoe, Brian P.; Friedman, Jonathan M.
Flow reconstructions in the Upper Missouri River Basin using riparian tree rings
River flow reconstructions are typically developed using tree rings from montane conifers that cannot reflect flow regulation or hydrologic inputs from the lower portions of a watershed. Incorporating lowland riparian trees may improve the accuracy of flow reconstructions when these trees are physically linked to the alluvial water table. We used...Schook, Derek M.; Friedman, Jonathan M.; Rathburn, Sara L.
Resource management and operations in central North Dakota: Climate change scenario planning workshop summary November 12-13, 2015, Bismarck, ND
The Scaling Climate Change Adaptation in the Northern Great Plains through Regional Climate Summaries and Local Qualitative-Quantitative Scenario Planning Workshops project synthesizes climate data into 3-5 distinct but plausible climate summaries for the northern Great Plains region; crafts quantitative summaries of these climate futures for two...Fisichelli, Nicholas A.; Schuurman, Gregor; Symstad, Amy J.; Ray, Andrea; Friedman, Jonathan M.; Miller, Brian; Rowland, Erika
Using NDVI to measure precipitation in semi-arid landscapes
Measuring precipitation in semi-arid landscapes is important for understanding the processes related to rainfall and run-off; however, measuring precipitation accurately can often be challenging especially within remote regions where precipitation instruments are scarce. Typically, rain-gauges are sparsely distributed and research comparing rain-...Birtwhistle, Amy N.; Laituri, Melinda; Bledsoe, Brian; Friedman, Jonathan M.
Debris flow occurrence and sediment persistence, Upper Colorado River Valley, CO
Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has...Grimsley, Kyle J; Rathburn, Sara L.; Friedman, Jonathan M.; Mangano, Joseph F.