Terraced paddy field rainfall-runoff mechanism and simulation using a revised tank model

Abstract

Terraced paddy fields play important roles in water and soil conservation because their water storage effect reduces and delays flood peaks. This study applies the terraced paddy field rainfall-runoff mechanism to the tank model. Though the traditional four-section tank model can easily simulate rainfall-runoff in a terraced paddy field, it has many parameters that are difficult to calibrate. To address the shortcomings of the traditional four-section tank model, this study develops a revised tank model to simulate rainfall-runoff. This study selects a terraced paddy field located in Hsuing-Pu village in Hsiuing-Chu County as the experimental field. The field under investigation was equipped with automatic monitoring stations, water-stage, and rain gauges. These stations collected data on rainfall and water flow to simulate the rainfall-runoff model in that region. To simulate the runoff behavior of the experimental terraced paddy field, two rainfall events were selected from the gathered data and five normal evaluation indexes based on static and hydrological theory were applied to calculate the results of simulation simultaneously. The revised tank model performed better than expected, and precisely predicted the variations and trends in flow charge. Comparison with representation indexes proved that the revised tank model is an appropriate and valuable tool for rainfall-runoff simulation

Application of a tank model to assess the flood-control function of a terraced paddy field

“…Chang et al (2001) indicated that an excessive number of tanks will only increase the time needed for calculation and the improvement of the simulation results is limited. In fact, a simplified two-layered tank model is also suitable for paddy fields (Chang et al 2001, Chen andYang 2011).…”

“…Therefore, several researchers have used the tank model. The runoff-calculation method and characteristics of this model are as follows (Chen and Yang 2011): (a) The model automatically includes the first flush loss and the amount of loss variation during rainfall. They can be determined by the effluent height of the top tank and the infiltration hole.…”

“…Chen and Yang (2011) applied a revised tank model to assess the rainfall-runoff mechanism of terraced paddy fields under various types of rainfall events. The waterstorage capacity of a paddy field is mainly dependent on the size of the field, the height of the bund, and the outlet (or weir) within the bund.…”

Rainfall–Runoff Research on Upland Fields and A Comparison Of Kinematic Wave and Improved Tank Models

“…The results showed that this basin of rice fields is able to provide a accurate simulation and groundwater recharge. Yang and Chen (2010) applied a revised tank model to simulate the rainfall-runoff mechanism in terraced paddy fields, and applied five normal evaluation indexes based on static and hydrological theories to calculate the results. The revised tank model performed more favourably than expected, and precisely predicted the variations and trends in flow discharge.…”

“…Comparison of representative indexes proved that the revised tank model was an appropriate and valuable tool for simulating rainfall runoff. Nakagiri et al (1999), Lee et al(1996), Yang and Chen (2010), Takeuchi et al (2009) have described the subsurface flow and saturated excess overland flow on the slopes of hills with a soil layer overlaying a relatively impermeable bedrock by applying the kinematic wave model. The runoff, groundwater level, and soil moisture content have been calculated in several rainfall-runoff models by using the kinematic wave approach…”