A Study of the Load Allocation using Watershed Model and Load Duration Curve in TMDL

Abstract

Total Maximum Daily Load (TMDL) system in Korea is a system that manages the discharge load per unit watershed to achieve the water quality target under the conditions of the six month flow (Q275) and the low water discharge (Q185). However, since the flow conditions of water quality are various in each unit watershed, it is necessary to understand the effect of improving the water quality by flow duration analysis in order to operate an effective TMDL. In this study, the HSPF model was operated by the flow and TP after calibration and verification, and the Low Duration Curve (LDC) was created using simulation results. LDC was used to calculate the excess rate of the water quality target for each flow condition. The scenario to install the artificial wetland was applied to the model for the water quality target and the achievement of the water quality target by the flow duration analysis was evaluated. In addition, the management system of TMDL in Korea would be developed more scientifically by suggesting the allocation load considering the baseline discharge and the safety discharge so that the water quality target can be achieved by the flow duration analysis in the study area.