31.3 Determining the Scope of the Assessment: Workshop 1
463
portant factor in the slow but progressive degradation of the river's ecology. At the same time, it was
recognized that the navigation system on the Mississippi supports considerable economic activity
that is significant at regional, national, and international scales. To explore what flexibilities might
exist in water control regimens and in natural systems, conferees recommended that an ecosystem
assessment be completed for the Upper Mississippi
River System to determine the potential for restoring the natural river hydrograph, floodplain connectivity, and energy dynamics.
Over the next several months, the Minnesota Department of Natural Resources' Mississippi River
Team met with river scientists from the five-state
region and assembled an ad hoc steering committee to pursue an AEA. Since then, the Upper Mississippi River AEA Steering Committee has
planned and implemented phase I of a multipart effort. This first phase has focused on identifying key
factors in the way the river works, describing these
factors' interrelationships, and developing a computer simulation model that attempts to capture
these basic interactions. The Legislative Commission on Minnesota Resources, McKnight Foundation, and National Biological Service provided
funding for phase I of the UMR AEA.
The Upper Mississippi River Basin Association
has administered the phase I funding. The balance
of this report describes the progress that has been
made through two phase I workshops and related
model development efforts. The report is intended
to bring closure to phase I of the UMR AEA and
set the stage for phase II, which will focus on using a refined simulation model to explore various
management scenarios, with an emphasis on identifying promising ways to reconcile competing demands on the river.
31.3 Determining the Scope of the
Assessment: Workshop 1
An AEA usually begins with a scoping workshop
in which key resource issues are defined, the types
of policy actions or interventions are identified, and
the critical processes and indicators of ecosystem
response are developed. The scoping process leads
to the next stage of assessment, when the pieces
identified in the scoping session are put into a computer model. On December 5-7, 1995, a scoping
workshop was held at the Alverna Center in
Winona, Minnesota, to begin a series of structured
conversations to assess environmental issues on the
Upper Mississippi River. The workshop brought together approximately 45 people with a wide range
of experiences, disciplinary backgrounds, and understanding about the river. The scoping workshop
for the UMR AEA was organized around a series
of plenary and small working group sessions aimed
at developing a framework and ingredients for a
computer model. Participants discussed resource
issues, potential management actions, and the spatial and temporal scale of the analysis. A team of
modeling consultants with considerable AEA experience provided technical guidance.
31.3.1 Resource Issues
Attendees at the December 1995 workshop concluded that resource issues on the Upper Mississippi could be grouped into physical, biological,
and human components. The physical issues include changes to the natural hydrograph of the river
and geomorphological modifications of the river
channel and floodplain, including dams, wing
dikes, levees, and the effects of impoundment.
These changes affect the relationship between stage
and discharge and the movement of water and sediments between the main channel and the floodplain and within the floodplain. The primary biological issues stem from the effects of physical
modifications, including a decrease in the abundance and diversity of habitat types within the river
and the riparian zone, loss of biotic diversity and
of individual species, and changes in the movement
patterns and abundance of fish. Human issues include the economic effects of commercial navigation, public access for recreational use, and future
trends in population growth and floodplain development.
31.3.2 Management Actions
to Be Simulated
Workshop participants identified a variety of potential management actions to be addressed by
modeling, including those that could be applied
within the river and others relating to the upland
drainage area. Key physical variables that they
wanted to manipulate with the model included the
stage of the river, distribution of flow within the
main channel and backwaters, and changes in land
contours in backwater or impounded areas (e.g.,
building or removing levees, dredging deep holes).
Participants also identified key management variables related to navigation, including changes in the
channel depth and dredging policy, changes to the
carrying capacity of barges, and alternative forms
of transportation.
463
portant factor in the slow but progressive degradation of the river's ecology. At the same time, it was
recognized that the navigation system on the Mississippi supports considerable economic activity
that is significant at regional, national, and international scales. To explore what flexibilities might
exist in water control regimens and in natural systems, conferees recommended that an ecosystem
assessment be completed for the Upper Mississippi
River System to determine the potential for restoring the natural river hydrograph, floodplain connectivity, and energy dynamics.
Over the next several months, the Minnesota Department of Natural Resources' Mississippi River
Team met with river scientists from the five-state
region and assembled an ad hoc steering committee to pursue an AEA. Since then, the Upper Mississippi River AEA Steering Committee has
planned and implemented phase I of a multipart effort. This first phase has focused on identifying key
factors in the way the river works, describing these
factors' interrelationships, and developing a computer simulation model that attempts to capture
these basic interactions. The Legislative Commission on Minnesota Resources, McKnight Foundation, and National Biological Service provided
funding for phase I of the UMR AEA.
The Upper Mississippi River Basin Association
has administered the phase I funding. The balance
of this report describes the progress that has been
made through two phase I workshops and related
model development efforts. The report is intended
to bring closure to phase I of the UMR AEA and
set the stage for phase II, which will focus on using a refined simulation model to explore various
management scenarios, with an emphasis on identifying promising ways to reconcile competing demands on the river.
31.3 Determining the Scope of the
Assessment: Workshop 1
An AEA usually begins with a scoping workshop
in which key resource issues are defined, the types
of policy actions or interventions are identified, and
the critical processes and indicators of ecosystem
response are developed. The scoping process leads
to the next stage of assessment, when the pieces
identified in the scoping session are put into a computer model. On December 5-7, 1995, a scoping
workshop was held at the Alverna Center in
Winona, Minnesota, to begin a series of structured
conversations to assess environmental issues on the
Upper Mississippi River. The workshop brought together approximately 45 people with a wide range
of experiences, disciplinary backgrounds, and understanding about the river. The scoping workshop
for the UMR AEA was organized around a series
of plenary and small working group sessions aimed
at developing a framework and ingredients for a
computer model. Participants discussed resource
issues, potential management actions, and the spatial and temporal scale of the analysis. A team of
modeling consultants with considerable AEA experience provided technical guidance.
31.3.1 Resource Issues
Attendees at the December 1995 workshop concluded that resource issues on the Upper Mississippi could be grouped into physical, biological,
and human components. The physical issues include changes to the natural hydrograph of the river
and geomorphological modifications of the river
channel and floodplain, including dams, wing
dikes, levees, and the effects of impoundment.
These changes affect the relationship between stage
and discharge and the movement of water and sediments between the main channel and the floodplain and within the floodplain. The primary biological issues stem from the effects of physical
modifications, including a decrease in the abundance and diversity of habitat types within the river
and the riparian zone, loss of biotic diversity and
of individual species, and changes in the movement
patterns and abundance of fish. Human issues include the economic effects of commercial navigation, public access for recreational use, and future
trends in population growth and floodplain development.
31.3.2 Management Actions
to Be Simulated
Workshop participants identified a variety of potential management actions to be addressed by
modeling, including those that could be applied
within the river and others relating to the upland
drainage area. Key physical variables that they
wanted to manipulate with the model included the
stage of the river, distribution of flow within the
main channel and backwaters, and changes in land
contours in backwater or impounded areas (e.g.,
building or removing levees, dredging deep holes).
Participants also identified key management variables related to navigation, including changes in the
channel depth and dredging policy, changes to the
carrying capacity of barges, and alternative forms
of transportation.