Evaluation of cloud seeding on the securement of additional water resources in the Boryeong Dam Basin, Korea

Abstract

This study evaluates the effect of cloud seeding on the increase of runoff or securing of additional water resources. Unlike previous studies, this study concentrates more on the change of various components of the hydrologic processes. Both the event-based analysis and the annual analysis are conducted to evaluate the change of these components. The Boryeong Dam Basin in Korea is considered as a study basin. The WRF (Weather Research and Forecasting) model is used in the cloud seeding simulation, while the PRMS (Precipitation Runoff Modeling System) model is used in the rainfall–runoff analysis. The target years of this study are 2018 and 2019. As results, the event-based analysis shows that the infiltration, effective rainfall, interflow, and direct runoff are increased relatively more among the eight rainfall-runoff components considered in this study. In particular, the increase of interflow is noticeable. More than 60 % of the increased rainfall is found to contribute to the runoff increase. In the annual analysis, this ratio is found to become even higher. The ratio is estimated to be more than 90 %, which is mostly due to the contribution of baseflow. As important factors controlling the effectiveness of cloud seeding, the effects of antecedent soil moisture and threshold daily rainfall depth on the increase of total runoff are also evaluated. The results show that wet soil condition is more favorable to the successful cloud seeding experiment to secure additional water resources. Also, it is confirmed that the cloud seeding experiment can be more effective when the daily rainfall is more than 20 mm. Finally, the results of this study imply the efficiency of cloud seeding and its economic values are potentially high.