DESIGN OF A RESILIENT MAINTENANCE FLOW BASED ON THE STATE ANALYSES

Abstract

 The current estimation method of maintenance flow has three challenges: lack of methods to consider flow variabilities, only a few target are considered to evaluate the habitat, and lack of monitoring method. This research analyzed the current condition of the 100 class A rivers which have maintenance flow standards. The result revealed that 70% of the maintenance flow was set as constant throughout the year, while few rivers consider seasonality of flow. As for habitat conservation, the maintenance flow was found to be roughly determined by the minimum water depth and velocity of the 12 target fish. In order to set more effective maintenance flow standards, it is necessary to take into account not only magnitude of flow but also to frequency, timing, duration and rate of change. It is also necessary to incorporate monitoring into the guideline and to have a flexible system by reviewing the maintenance flow together with revision schedule of the river improvement plans.