Kum River (Korea) Water Conflict Negotiation Model
Project background
Research Goal
Water Conflict Resolution Model
Model Application
Model Output
Conclusions
Future Work
References
The Kum River basin is one of
most important river basins in Korea. This river provides
benefits for some five million people in the
form of water
supply, irrigation, hydropower, and recreation. Two major dams
are located on this river, Daechong Dam (constructed in the
1970's) and Yongdam Dam which is located upstream of Daechong
Dam (and whose construction is just recently completed). Two
major droughts have occurred in this basin, one in 1995 and one
in 2001. These recent droughts have accentuated the need for
careful planning in the basin and have highlighted potential
trade-offs. The initial filling of Yongdam Dam was delayed due
to concerns that its operation would negatively impact water
availability at Daechong Dam.
Since this region's population is
projected to grow very rapidly, larger demands will soon be made
on Yongdam Dam's storage and downstream users are concerned that
these demands may decrease the reliability of their water. In
addition, there is considerable debate over what values should
be established for environmental flows for both dams. The
environmental releases from Daechong Dam have a significant
impact on water quality downstream of the dam. Environmental
releases from Yongdam Dam impact both the water quality between
the two dams and the inflows to Daechong Dam.
These trade-offs between water
supply reliability and environmental flows are explored in this
project. Analyses were made using a water resource model of the
basin, developed using the STELLAŽ software environment
This research describes the
development of water resources, conflict resolution model to
evaluate the impact of water management alternatives in Kum
River basin under droughts. Such a model is necessary to support
decision making in the basin, as well as for providing useful
insights to potential conjunctive operation of the dams. In
addition, the results of this study can contribute to promote
long-term water sustainability in this region.
Conflicts occur in water
resources planning and management for a variety of reasons. In
general, water conflicts occur when people disagree about how
much water of a given quality is available at a specific region
for a specific purpose at a particular time (Palmer et. al,
1999). Conflicts can be resolved in many ways, through
litigation, through formal agreements, through legislative
order, through mediation, and through informed discussions. Lord
et al. (1979) notes that water conflicts tend to arise because
of disputes associated with perceived ownership, because of
differences in how resources are valued, and because of
differing interests. Computer models can be used to address both
the reasons for conflicts and our perception of conflicts.
Many computer simulation models have been widely applied to
water resource planning and management. By the 1980's, Corps of
Engineers Hydrologic Engineering Center (HEC) developed the
HEC-3 and HEC-5, applied for conservation storage and flood
control systems (Yeh, 1985). Optimization models have also been
widely used in reservoir system studies as well as water
allocation studies. During the 1990's, Palmer et. al. (1993)
introduced "Shared Vision Model" as a procedure that allows
interested participants to achieve consensus by forming a shared
vision of a system or process. The goals of shared vision
modeling are to:
- provide insight into questions
and concerns generating conflicts
- include information that
represent the interests and perspectives of all participants
- obtain equitable benefits for
all participants
- provide the opportunity for a
high level of involvement by all stakeholders.
The Shared Vision Modeling
environment include STELLAŽ (High Performance Systems 1992),
ExtendTM (Imagine That 1992), PowerSimŽ (MicroWorlds, 1995),
SIMULABTM (The Math Works, Inc. 1991), and DS Lab Pro (DS Group
1993). The Shared Vision Model built in STELLAŽ framework has
been widely applied for National Drought Study (NDS) in national
wide including Washington, Virginia, West Virginia, Kansas,
Missouri, and Massachusetts. A benefit of the shared vision
modeling approach is interactive use in a group setting to
support joint fact finding, policy dialogue and alternative
evaluation. This approach was viewed as an appropriate one to be
applied to the Kum River basin to resolve water conflict.
The project focuses on an
application of the water conflict resolution model based on the
Shared Vision modeling approach. Researchers at the University
of Washington (UW) have had the opportunity to begin to apply
the Shared Vision modeling approach to Kum River basin in Korea.
The purpose of this research is to assess an existing plan, to
develop alternatives for the management of all water resources
in the region, and to resolve the water conflict based on an
appropriate mechanism for implementing the plan.
There are a number of operational issues associated with the
current water resources conflict in the Kum River basin.
Instream flows downstream of Daechong Dam and instream flows
between reservoirs are under debate and widely different values
are being suggested. The construction of Yongdam Dam and the
continued growth in this basin has created the need to address a
number of fundamental water resource questions. The models
developed in this research address specific planning issues that
must be resolved in the basin. These issues include: 1) An
appropriate fishflow target between dams; 2) Safe yield of both
dams as a function of established fish flow; 3) Benefits of
conjunctive operation; and 4) Relative water distribution in the
two dams. These general concerns can be framed into a series of
questions that explore system operation and management,
including:
- What was the safe yield of the Daechong Dam before Yongdam Dam was constructed?
- What is the safe yield of both dams, if they are operated for
a single, downstream user and there is no required environmental
flow?
- How much of this yield is lost if there are required
environmental flows between the two dams?
- How much yield is lost when there are required environmental
flows downstream on Daechong Dam?
The analysis begins with the
selection of model parameters and year of interest to analyze.
The model incorporates the regional hydrology, conjunctive
reservoir management and operating rules, and multi-objective
programming to illustrate the trade-offs between system
reliability, operating strategy, environmental flows, and
drought triggers. Operational parameters under consideration
were incorporated into the Shared Vision model. The safe yield
of the system was defined as the maximum amount of water that
could be taken from the reservoir system over the twenty-year
historic record that resulted in a failure in one year.
Appropriate operating policies that improved the performance of
the conjunctive system with respect to safe yield were developed
in the course of this research. The model is designed
specifically as a conflict resolution tool to allow its
incorporation into the ongoing debate concerning the regional
goals and objectives of water management in this basin. This
design required that the model be user friendly and technically
detailed to allow its results will be accepted by those that
will eventually arrive at a compromise between the various
conflicting operational objectives.
Safe Yield of Daechong Dam
The safe yield of Daechong Dam prior to the construction of
Yongdam Dam was calculated to be 40.1 cubic meters per second
(m3/s). This value assumes that all water entering the dam could
be diverted for use. The safe yield of the system was also
calculated with different environmental flows downstream. The
results of this analysis are presented in Table 1. The table
indicates the expected trade-off between providing more water
downstream and the ability to provide water to divert from the
system. This yield (40.1 m3/s) represents that maximum yield
that could have been provided from the Daechong Dam. It can be
considered the "status quo" value for the uses of Daechong Dam,
prior to the construction of Youngdam Dam.
Safe Yield of Daechong Dam and
Yongdam Dam
It is instructive to determine the yield of both Daechong Dam
and Yongdam Dam as the starting point of negotiations between
the two. This value represents the total yield of the system
after Yongdam Dam's construction, and could be view by the
downstream users of the water that rightfully belongs to them.
The difference between this value and the yield of the Daechong
Dam without Yongdam Dam could, from a different perspective, be
considered the amount of yield that should be provided to the
users of the Yongdam Dam.
Table 1.
Safe yield of Daechong Dam with varying fish flows, without
Yongdam Dam.
|
Flow below Daechong (m3/s) |
Safe Yield (m3/s) |
|
0 |
40.1 |
|
5 |
36.3 |
|
10 |
29.6 |
|
15 |
23.9 |
|
21 |
18.1 |
Table 2 presents the results of
an analysis that calculates the yield of the two-reservoir
system. In general, the yield of the system increases by
approximately 11 m3/s. On could argue that the users of the
Yongdam Dam should not expect more than 11 m3/s of yield from
the system, because taking more than this would decrease the
yield of the more senior user of the river. If less than 11 m3/s
is taken from Yongdam Dam, however, the construction of the new
dam could be viewed as a regional benefit.
Table 2.
Safe yield of Daechong Dam with varying fish target below,
with new dam operation that support Daechong Dam.
|
Flow below Daechong (m3/s) |
Safe Yield (m3/s) |
|
0 |
52.0 |
|
5 |
46.3 |
|
10 |
41.3 |
|
15 |
36.3 |
|
21 |
29.7 |
Safe Yield of Yongdam Dam
Another perspective is to ignore any previous beneficial uses of
the water and to assume that when Yongdam Dam is constructed,
its users will consume the entire yield that they can derive
from the project. This value was also calculated, based upon an
appropriate assumption for the appropriate portion of the
streamflows that would flow into Yongdam Dam. The yield of this
system proved to be 13.8 m3/s. It should be noted that this
value is very similar to the increased yield of the
two-reservoir system.
Impact of Environmental Flows
on Yongdam Dam and on Daechong Dam
Because of water quality concerns, the flow between the two dams
is very important. The ability to operate the two reservoirs
conjunctively to maximize yield can be negatively impacted if
environmental flows between the two dams cause system storage to
be inequitable between the reservoirs. Setting the environmental
flow at a high value between Yongdam Dam and Daechong Dam can
also significantly decrease the yield of Yongdam Dam while
increasing Daechong Dam.
Table 3 presents the safe yield
of Daechong Dam and Yongdam Dam for two assumptions relating to
the environmental flows between the dams. The yield of Yongdam
Dam is very sensitive to fish flows between dams. As noted
previously, the yield of Yongdam Dam, without environmental
flows between the two dams is 13.8 m3/s. If an environmental
flow of 5.4 m3/s is maintained, the yield drops to 8.1 m3/s. If
an environmental flow of 12.4 m3/s is maintained, the yield
drops essentially to zero. The yield of the Daechong Dam
benefits from increasing fish flows between the two dams,
increasing from 23.9 m3/s to 31.4 m3/s as the fish flow
requirement increases.
Table 3.
Safe yield of Daechong Dam with fish targets between the dams..
|
Year |
Flow below Daechong (m3/s) |
Flow below Yongdam (m3/s) |
Safe Yield of Daechong Dam (m3/s) |
Safe Yield of Yongdam Dam (m3/s) |
|
2010 |
21 |
5.4 |
23.9 |
8.1 |
|
2010 |
21 |
12.4 |
31.4 |
0.79 |
This analysis
illustrates the range of benefits that can be obtained during
drought years similar to 1988 and 1995 by the construction of
the Yongdam Dam. It appears that the construction of Yongdam Dam
can provide benefits to both upstream and down stream users of
the Kim River. The additional storage provided by this dam could
be used for many purposes including providing water to upstream
users and ensuring that environmental flows can be maintained
between the two reservoirs. Yongdam Dam could also, perhaps,
provide additional water during drought periods to downstream
users, water that would not have been available unless the dam
was constructed.
However, there are clear conflicts between the environmental
flows established downstream of Daechong and the amount of water
that can be diverted for municipal, industrial and agricultural
water supply from that dam. There are also clear conflicts
between the environmental flows established between the two dams
and the ability to supply water from Yongdam Dam.
The advantages of a model such as the one developed in this
research is that these trade-offs can be clearly illustrated to
stakeholder groups and that decisions can be made based upon a
foundation fact, rather than conjecture. As the water supply
needs and demands in the region change, and as the value of the
water for various uses is more clearly defined, informed
decisions can be made to allow for the best management possible.
This work was
funded by KICT (Korea Research Institute of Construction and
Technology)
With the
completion of the simulation model of the Kum River basin, the
authors anticipate continued efforts to evaluate potential water
management trade-offs in the basin and the opportunity to work
with stakeholders to better incorporate regional considerations,
constraints, and objectives. Because the establishment of
environmental flows will have a significant impact on system
yield and because the region continues to grow, the conflicts
will worsen unless cooperative solutions can be reached.
A number of improvements, enhancements, and new directions can
be taken to provide increased decision support in the Kum River
basin. These new directions may include:
- Development of a detailed
Drought Management Plan to support system operation and
management during periods of low flow,
- Development of evaluation criteria (reliability, resiliency,
and vulnerability) for system operation during drought,
- Advanced analysis of the influence that instream flow
requirements have on system safe yield, and
- Economic evaluation of the trade-offs between instream flow
values and water used in the basin for other purposes.
Karpack,
L. M., Palmer, R. N. (1992) "Use of Interactive Simulation
Environments for Evaluation of Water Supply Reliability",
Proceedings of the Water Forum'92, ASCE, 144-149.
Lord,
W.B., L. Adelman, P. Wehr, C. Brown, R. Crews, B. Marvin, and M.
Waterstone (1979). Conflict Management in Federal Water Resource
Planning, Office of Water Research and Technology, Washington,
DC.
Palmer,
R. N., Werick, W. J., MacEwan, A., Woods, A. W. (1999) "Modeling
Water Resources Opportunities, Challenges and Trade-offs: The
Use of Shared Vision Modeling for Negotiation and Conflict
Resolution", Proceedings of the 26th Annual Conference, Water
Resources Planning and Management, ASCE, Tempe, AZ, June.
Yeh, William W. G. (1985). "Reservoir
Management and Operations Models: A State of the Art Review."
Water resources Research 21(12): 1797 - 1818.
Updated
05/13/2005
