Abstract
In this paper, the runoff properties in a forest and a terraced paddy filed catchment were compared and discussed according to the analysis by a long-term runoff model. By the comparison of observed discharge, it was found that storm runoff in the terraced paddy field catchment responds rapidly to rainfall and the peak discharge is greater than that of the forest catchment. It was also concluded that the amount of low flow discharge in the terraced paddy field catchment decreases remarkably comparing to the forest catchment during irrigation season, while no specific differences were identified during non-irrigation season. As the result of application of a simple long-term runoff model which is composed of single row of tanks, the model performance was not so good for the terraced paddy field catchment. Therefore, a distributed model which was composed of parallel row was introduced to represent the properties of soil and water management in the terraced paddy filed and the performance of the model was discussed. Then, better results were obtained, especially in low flow discharge during the irrigation season. Moreover, it was confirmed that the identified parameters reflected the hydrologic properties in the terraced paddy field.
