Abstract
Antecedent soil moisture is a key factor to determine flood characteristics. Understanding the role of antecedent soil moisture for flood is needed for conservation of ecosystem and for damage mitigation as well. The aim of this study is to quantify the relationships of the antecedent soil moisture to flood volume, peak discharge and its duration. Discharge and soil moisture were simulated by a hydrological model. Then, multiple linear models quantified the relationships. Thirty-five floods were analyzed from 2005 to 2012 in Huong River, Vietnam. As a result, not only total precipitation volume but also soil moisture before flooding explained flood volume and its duration. Similarly, antecedent soil moisture increased the predictability of peak discharge with peak rainfall amount. The flood characteristics changed by reflecting wet/dry condition at top soil. We expect that consideration of antecedent soil moisture to identify the flood characteristics accurately leads to practical flood countermeasure.
