Jeong-Seok Yang

Prioritizing Feasible Locations for Permeable Pavement Using MODFLOW and Multi-criteria Decision Making Methods

This study provides a systematic three-step approach to prioritizing feasible locations for permeable pavement, taking into account environmental, economic, and social aspects. Step 1 is the identification of potential locations on the basis of spatial and economic feasibility, and on the receptiveness of the local government and residents. Step 2 involves the use of Visual MODFLOW software to simulate groundwater levels with and without permeable pavement. Step 3 is the prioritization of all feasible locations using three multi-criteria decision making methods: the weighted sum method, composite programming and TOPSIS. Weighting values were derived from iterative feedback surveys completed by 22 regional experts. This framework was applied to the Mokgamcheon watershed, central Korea, which suffers from instream flow deficit during the dry season. The results show that by considering anthropogenic factors and hydrological effectiveness, this approach effectively prioritizes feasible alternatives that can be implemented into comprehensive hydrological cycle rehabilitation plans.

Contribution of baseflow during dry spells in irregular channel cross section

&NA; The discharge and water level of a gaining stream are known to be maintained during dry spells by baseflow, which is defined as discharge from underground storage. However, the effect of baseflow on a real river is not well known because direct measurements of baseflow in field are difficult to conduct. Therefore, this study attempts to clarify the contribution of baseflow to streamflow and the extent to which the water level is maintained even during dry spells. A digital filter technique is applied to the records of daily mean streamflow in order to estimate the amount of baseflow, and the lateral distribution method is applied to irregular cross sections at observational sites to obtain the stage‐discharge rate curve. Through a comparison of the observed data and calculation results, the amount of baseflow is estimated across the channel, in addition to the maximum water level retained during dry spells in relation to the baseflow. Finally, based on the results of an energy conservation model, this study proposes that the source of the amount of baseflow estimated across a channel section may be different from that of the water level maintained during dry spells.