Land cover and land use (LC/LU), climate, and biogeochemical processing are significant drivers of water quality in streams and rivers over broad scales of space and time. As LC/LU and climate continue to change we can expect changes in water quality. This project seeks to understand the drivers of spatial and temporal variability in water quality across scales using new and existing data to improve our ability to predict the impact of changing LC/LU and climatic anomalies on water quality in regional stream networks. Our study focuses on the Upper Mississippi River Basin as an ideal location to make progress in this area due to its size, LC/LU distribution, and regional importance.
Statement of Problem: Land cover and land use (LC/LU), climate, and biogeochemical processing are significant drivers of the concentrations and loads of carbon, nutrients (nitrogen and phosphorus), and products of geologic weathering in streams and rivers over broad spatial and temporal scales. While knowledge of watershed LC/LU can help explain water quality at a given location, the spatial and temporal influence is likely to vary by type of constituent, hydrologic regime, and intensity of the specific LC/LU. A common generalization is that water quality across headwater streams (starting point of streams) is highly variable in time and space, and that water quality variability decreases with downstream transport and the incorporation of water from a greater contributing area. While this is a reasonable generalization, this type of analysis is relatively untested for a broad range of constituents and spatial and temporal scales.
In this project we propose to investigate the spatiotemporal variance of water quality in stream networks using existing and newly acquired data from multiple watersheds varying in size, LC/LU, climate, and geologic setting to advance our understanding and predictions of surface water carbon and nutrients dynamics across scales. This project will build upon recent efforts in the Upper Mississippi River Basin (UMRB), which focused on targeted water quality sampling and the concentrations, fluxes, and transformation of carbon, nitrogen, and major ions throughout the watershed from headwater streams to the mainstem Mississippi River over two years, 2015-2017. The UMRB, which we define as the area upstream of Lock & Dam 8 near LaCrosse, WI, provides an ideal opportunity to investigate network-level connections in a nationally significant watershed (Figure 1a).
Extreme contrasts in land cover and land use exist in the basin which contains areas of intense agricultural usage, large urban centers, and relatively undeveloped forests and wetlands (Figure 1b). Furthermore, large differences in the underlying geology of the region create differences in major ions concentrations and fluxes. The western part of the basin is mostly glacial moraine deposits with high concentrations of calcium, alkalinity, and other weathering products. The eastern part of the basin is underlain with extensive sand deposits and tends to have more dilute surface waters that are higher in iron and dissolved organic carbon. The east and west portions of the basin contribute approximately equally to streamflow, but the timing, intensity, and geographic location of runoff events can vary dramatically throughout the year. Therefore, this basin provides a unique opportunity to investigate how network connections create water quality conditions in a diverse, medium-sized watershed.
Why this Research is Important: Water quality impacts the health of humans, wildlife, and habitat, and has important economic implications for water treatment facilities, recreation, and food supply. It is vital to understand the complex drivers of water quality in stream networks to predict the outcome of human activity and climate change on water quality, and for identifying effective mitigation techniques for water quality management. Our proposed work will advance our ability to integrate watershed and process-level information across scales in a meaningful way and contribute to efforts such as water quality model development.
Objective(s): This project will address the following questions:
- How do carbon transport and processing vary across large spatial scales of the Upper Mississippi River Basin?
- How do spatial patterns of water quality vary with flow regime across the Upper Mississippi River Basin?
Methods: This project will leverage existing data in the UMRB watershed which was collected with the purpose of understanding the spatial and temporal structure of carbon fluxes and includes important data on nitrogen and major ions across scales and distinct systems. This data will greatly enhance our ability to utilize headwater stream information to predict downstream water quality, and to target locations for increased monitoring for applications such as hazard assessment and effectiveness of management activities. We will also collect new data in the UMRB aimed at increasing coverage of small streams across the diverse LC/LU types (especially agriculture) under high and low flow conditions. We will use short-term, high-frequency sensor field deployments and experimentation to discern rates and spatial distribution of relevant in-stream biogeochemical processes to use as a basis for filling knowledge gaps and for conceptual model development of stream network water quality.
Below are other science projects associated with this project.
Linking water, carbon, and nitrogen cycles in seasonally snow-covered catchments under changing land resource conditions
SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
LandCarbon
Below are data or web applications associated with this project.
Water quality, quantity, and gas fluxes of the Upper Mississippi River basin (WY 2012-2016)
Below are publications associated with this project.
Watershed carbon yield derived from gauge observations and river network connectivity in the United States
Dissolved carbon export by large river systems is influenced by source area heterogeneity
Anthropogenic landcover impacts fluvial dissolved organic matter composition in the Upper Mississippi River Basin
Bioavailability of dissolved organic matter varies with anthropogenic landcover in the Upper Mississippi River Basin
Lagged wetland CH4 flux response in a historically wet year
Biological and land use controls on the isotopic composition of aquatic carbon in the Upper Mississippi River Basin
Spatial and temporal patterns of dissolved organic matter quantity and quality in the Mississippi River Basin, 1997–2013
Below are partners associated with this project.
- Overview
Land cover and land use (LC/LU), climate, and biogeochemical processing are significant drivers of water quality in streams and rivers over broad scales of space and time. As LC/LU and climate continue to change we can expect changes in water quality. This project seeks to understand the drivers of spatial and temporal variability in water quality across scales using new and existing data to improve our ability to predict the impact of changing LC/LU and climatic anomalies on water quality in regional stream networks. Our study focuses on the Upper Mississippi River Basin as an ideal location to make progress in this area due to its size, LC/LU distribution, and regional importance.
Figure 1a. Upper Mississippi River Basin major tributary watersheds and sampling locations for 2015-17 study. Yellow dots mark mainstem Mississippi River, major tributary, and Chippewa River basin sampling sites that were visited quarterly during 2015-17; black dots and red dots mark targeted sampling sites visited one time during 2015-17. Creator: Sydney Foks, USGS, 2017. Statement of Problem: Land cover and land use (LC/LU), climate, and biogeochemical processing are significant drivers of the concentrations and loads of carbon, nutrients (nitrogen and phosphorus), and products of geologic weathering in streams and rivers over broad spatial and temporal scales. While knowledge of watershed LC/LU can help explain water quality at a given location, the spatial and temporal influence is likely to vary by type of constituent, hydrologic regime, and intensity of the specific LC/LU. A common generalization is that water quality across headwater streams (starting point of streams) is highly variable in time and space, and that water quality variability decreases with downstream transport and the incorporation of water from a greater contributing area. While this is a reasonable generalization, this type of analysis is relatively untested for a broad range of constituents and spatial and temporal scales.
In this project we propose to investigate the spatiotemporal variance of water quality in stream networks using existing and newly acquired data from multiple watersheds varying in size, LC/LU, climate, and geologic setting to advance our understanding and predictions of surface water carbon and nutrients dynamics across scales. This project will build upon recent efforts in the Upper Mississippi River Basin (UMRB), which focused on targeted water quality sampling and the concentrations, fluxes, and transformation of carbon, nitrogen, and major ions throughout the watershed from headwater streams to the mainstem Mississippi River over two years, 2015-2017. The UMRB, which we define as the area upstream of Lock & Dam 8 near LaCrosse, WI, provides an ideal opportunity to investigate network-level connections in a nationally significant watershed (Figure 1a).
Figure 1b. Upper Mississippi River Basin land cover and land use. Yellow dots are 2015-17 study sampling locations. Creator: Britta Voss, 2016. Extreme contrasts in land cover and land use exist in the basin which contains areas of intense agricultural usage, large urban centers, and relatively undeveloped forests and wetlands (Figure 1b). Furthermore, large differences in the underlying geology of the region create differences in major ions concentrations and fluxes. The western part of the basin is mostly glacial moraine deposits with high concentrations of calcium, alkalinity, and other weathering products. The eastern part of the basin is underlain with extensive sand deposits and tends to have more dilute surface waters that are higher in iron and dissolved organic carbon. The east and west portions of the basin contribute approximately equally to streamflow, but the timing, intensity, and geographic location of runoff events can vary dramatically throughout the year. Therefore, this basin provides a unique opportunity to investigate how network connections create water quality conditions in a diverse, medium-sized watershed.
Why this Research is Important: Water quality impacts the health of humans, wildlife, and habitat, and has important economic implications for water treatment facilities, recreation, and food supply. It is vital to understand the complex drivers of water quality in stream networks to predict the outcome of human activity and climate change on water quality, and for identifying effective mitigation techniques for water quality management. Our proposed work will advance our ability to integrate watershed and process-level information across scales in a meaningful way and contribute to efforts such as water quality model development.
Objective(s): This project will address the following questions:
- How do carbon transport and processing vary across large spatial scales of the Upper Mississippi River Basin?
- How do spatial patterns of water quality vary with flow regime across the Upper Mississippi River Basin?
Trout Creek near Bloomer, WI. Methods: This project will leverage existing data in the UMRB watershed which was collected with the purpose of understanding the spatial and temporal structure of carbon fluxes and includes important data on nitrogen and major ions across scales and distinct systems. This data will greatly enhance our ability to utilize headwater stream information to predict downstream water quality, and to target locations for increased monitoring for applications such as hazard assessment and effectiveness of management activities. We will also collect new data in the UMRB aimed at increasing coverage of small streams across the diverse LC/LU types (especially agriculture) under high and low flow conditions. We will use short-term, high-frequency sensor field deployments and experimentation to discern rates and spatial distribution of relevant in-stream biogeochemical processes to use as a basis for filling knowledge gaps and for conceptual model development of stream network water quality.
Water quality sample collection at Mississippi River near Red Wing, MN (People in picture are Britta Voss, Anne Kellerman, Dane Campbell). - Science
Below are other science projects associated with this project.
Linking water, carbon, and nitrogen cycles in seasonally snow-covered catchments under changing land resource conditions
Changes in snowpack accumulation, distribution, and melt in high-elevation catchments are likely to have important impacts on water, carbon, and nitrogen cycles, which are tightly coupled through exchanges of energy and biogeochemical compounds between atmospheric, terrestrial, and aquatic environments. Our research helps to better understand how changes in climate will affect water availability...SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Interactive, online SPARROW mapping tools allow for easy access to explore relations between human activities, natural processes, and...LandCarbon
The biologic carbon sequestration assessment program (LandCarbon) investigates ecosystem carbon cycle problems and develops carbon management science and monitoring methods. - Data
Below are data or web applications associated with this project.
Water quality, quantity, and gas fluxes of the Upper Mississippi River basin (WY 2012-2016)
This product consists of one tabular dataset and associated metadata of water quality information related to rivers, streams, and reservoirs in the Upper Mississippi River watershed between 2012 and 2016. This data release is a part of a national assessment of freshwater aquatic carbon fluxes. Data consist of organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calcu - Publications
Below are publications associated with this project.
Watershed carbon yield derived from gauge observations and river network connectivity in the United States
River networks play a critical role in the global carbon cycle. Although global/continental scale riverine carbon cycle studies demonstrate the significance of rivers and streams for linking land and coastal regions, the lack of spatially distributed riverine carbon load data represents a gap for quantifying riverine carbon net gain or net loss in different regions, understanding mechanisms and faAuthorsHan Qiu, Xuesong Zhang, Anni Yang, Kimberly Wickland, Edward G. Stets, Min ChenDissolved carbon export by large river systems is influenced by source area heterogeneity
Rivers and streams export inorganic and organic carbon derived from contributing landscapes and so downstream carbon fluxes are important quantitative indicators of change in ecosystem function and for the full accounting of terrestrial carbon budgets. Carbon concentration-discharge (C-Q) relationships in rivers provide important information about carbon source and behavior in watersheds and are uAuthorsEdward G. Stets, Robert G. Striegl, Kimberly Wickland, Mark Dornblaser, Sydney FoksAnthropogenic landcover impacts fluvial dissolved organic matter composition in the Upper Mississippi River Basin
Landcover changes have altered the natural carbon cycle; however, most landcover studies focus on either forest conversion to agriculture or urban, rarely both. We present differences in dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) molecular composition within Upper Mississippi River Basin low order streams and rivers draining one of three dominant landcovers (fAuthorsDerrick R. Vaughn, Anne M. Kellerman, Kimberly Wickland, Robert G. Striegl, David C. Podgorski, Jon R. Hawkings, Jaap Nienhuis, Mark Dornblaser, Edward G. Stets, Robert G. M. SpencerBioavailability of dissolved organic matter varies with anthropogenic landcover in the Upper Mississippi River Basin
Anthropogenic conversion of forests and wetlands to agricultural and urban landcovers impacts dissolved organic matter (DOM) within streams draining these catchments. Research on how landcover conversion impacts DOM molecular level composition and bioavailability, however, is lacking. In the Upper Mississippi River Basin (UMRB), water from low-order streams and rivers draining one of three dominanAuthorsDerrick R. Vaughn, Anne M. Kellerman, Kimberly Wickland, Robert G. Striegl, David C. Podgorski, Jon R. Hawkings, Jaap H. Nienhuis, Mark M. Dornblaser, Edward G. Stets, Robert G.M. SpencerLagged wetland CH4 flux response in a historically wet year
While a stimulating effect of plant primary productivity on soil carbon dioxide (CO2) emissions has been well documented, links between gross primary productivity (GPP) and wetland methane (CH4) emissions are less well investigated. Determination of the influence of primary productivity on wetland CH4 emissions (FCH4) is complicated by confounding influences of water table level and temperature onAuthorsJessica Turner, Ankur R. Desai, Jonathan Thom, Kimberly WicklandBiological and land use controls on the isotopic composition of aquatic carbon in the Upper Mississippi River Basin
Riverine ecosystems receive organic matter (OM) from terrestrial sources, internally produce new OM, and biogeochemically cycle and modify organic and inorganic carbon. Major gaps remain in the understanding of the relationships between carbon sources and processing in river systems. Here we synthesize isotopic, elemental, and molecular properties of dissolved organic carbon (DOC), particulate orgAuthorsBritta Voss, Kimberly P. Wickland, George R. Aiken, Robert G. StrieglSpatial and temporal patterns of dissolved organic matter quantity and quality in the Mississippi River Basin, 1997–2013
Recent studies have found insignificant or decreasing trends in time-series dissolved organic carbon (DOC) datasets, questioning the assumption that long-term DOC concentrations in surface waters are increasing in response to anthropogenic forcing, including climate change, land use, and atmospheric acid deposition. We used the weighted regressions on time, discharge, and season (WRTDS) model to eAuthorsSarah M. Stackpoole, Edward G. Stets, David W. Clow, Douglas A. Burns, George R. Aiken, Brent T. Aulenbach, Irena F. Creed, Robert M. Hirsch, Hjalmar Laudon, Brian Pellerin, Robert G. Striegl - Partners
Below are partners associated with this project.