poster - International Conference of Agricultural Engineering

Optimal Reservoir Operation Model with a Streamflow Network
Model and a Global Optimization Method
Mingoo Kang 1* , Seungwoo Park 2 , and Jooheon Lee 3
1
Research Fellow, Future Resources Institute, Woolim Lions Valley C-405, 371-28,
Gasan-dong, Keumcheon-gu, Seoul, South Korea, 153-786
2 Professor, Department of Rural Systems Engineering, Research Institute for Agriculture
and Life Sciences, College of Agriculture and Life Sciences, Seoul National University,
599 Gwanak-ro, Gwanak-gu, Seoul, South Korea, 151-742
3
Professor, Department of Civil Engineering, Joongbu University, 101 Daehak-ro,
Chubu-myeon, Geumsan-gun, Chungnam, South Korea, 312-702
*
Corresponding author. E-mail: kmg1218@gmail.com
Abstract
In this study, an optimal reservoir operation model is presented, featuring a nonlinear,
multiple-objective function and a global optimization method. In order to verify the
model’s applicability, the model is applied to optimal water allocations of both Balan
Reservoir and Seomjin Dam in South Korea that are an irrigation reservoir and a
multi-purpose, multi-outlet dam, respectively. For Balan Reservoir’s optimal operations,
a streamflow network model is used to simulate daily inflows, and a water demand
computation sub-model is developed, taking into account the amounts of water required
by irrigated rice paddy fields. The operation results show that optimal release patterns
are similar to those of the observed. For the optimal operations of Seomjin Dam, a
hydro-electric power outputs computation sub-model is developed and calibrated. The
results of the optimal operations for Seomjin Dam show that, during a wet term, the
hydro-electric power outputs increase by -7.52 to 10.04 %, varying with target water
stages; during a dry term, they increase by -5.94 to 3.98 %; and during a normal term,
they increase by 4.53 to 10.37 %. To solve an operation problem at Seomjin Dam that is
the result of the increase of water demand downstream of the dam, the model is applied to
various cases, considering the amounts of additional water supply. The results show that
in these cases that the amounts of additional water supply are less than 0.70 m 3 /sec with
target water stages lower than 194.0 m, the hydro-electric power outputs are more than
the historical average, and the total amounts of water supply are less influenced by the
amounts of additional water supply. Consequently, it is concluded that the model is
useful for evaluating the water supply capacities of water resources facilities and to
suggest amounts of additional water supply and new operation rules appropriate to the
changes in the circumstances related to water management of systems.
Key words: Optimal water allocation; Global optimization method; Streamflow network
model; Non-linear, multiple-objective function; Water supply capacity evaluation.
1. Introduction
In South Korea, on average, the annual rainfall amounts to 1,245 mm, that is 1.4 times
larger than the average in the world. However, the amount of the annual rainfall per
capita is 13.2 % of the average in the world. Since there are large gaps in rainfalls
among regions and seasons, water resources have been developed inequitably.
Particularly, because, during summer seasons, about two-thirds of the annual rainfalls
have been concentrated, non-effective runoffs have been generated, and floods have
occurred frequently. In order to resolve these problems that result from geographic and