Paddy Field Modelling System For Water Quality Management

Abstract

The objective of this study was to develop a paddy field modelling system for predicting pollutant (nutrient) loads and evaluating various best management practices (BMPs) on paddy fields. The system consists of a pre-processing component, the CREAMS-PADDY (Chemicals, Runoff, and Erosion from Agricultural Management Systems for PADDY) model, and a post-processing component. The CREAMS-PADDY was selected as the core model. The pre-processing component included manipulation of meteorological data, management of input parameters such as spatial characteristics and farming methods, batch running, and implementing various scenarios. The post-processing component contained visualization of water and nutrient balance components and statistical analyses for calibration, validation and application. To evaluate the applicability of the developed system, reduction effects on water control methods in paddy fields were simulated. Model parameters related to hydrology and water quality were calibrated and validated by comparing model predictions with field data collected over 2years. The simulation results indicated that reducing nutrient loss through surface drainage by water-saving irrigation and raising drainage outlet heights could protect downstream water quality. The simulation system will be a useful tool for planning BMPs to reduce nutrient loads from paddy fields in various regions including Korea. Copyright (c) 2016 John Wiley & Sons, Ltd.