Uncertainty, calibration and validation of the Mississippi Irrigation Scheduling Tool model

摘要

The current work presents the uncertainty analysis and its results of the Mississippi Irrigation Scheduling Tool (MIST) model, showing the margin of error (uncertainty) of the irrigation advice obtained through the web-based application. The basis forthe verification and validation of the model is also given. The MIST calculates the daily soil water balance in a crop field from daily weather measurements, irrigation, and rainfall, taking into account crop type, planting date, soil type, tillage, andother field-specific information. The MIST water balance calculations were validated using the local weather data that consisted of a few days of rain, and significant changes in the solar radiation, relative humidity and wind speed. The final water balance results showed values within acceptable ranges and comparable to in situ measurements of soil moisture. The final relative uncertainty in the water balance value was around 9%, which is in the normal range of the margin of error. The current MIST web-based application and uncertainty quantification have been preliminarily verified and validated. Further, the sensitivity analysis of the model reveal that net radiation on the crop surface, temperature and net evapotranspiration play a role in the evapotranspiration of water, specifically on the day of rainfall and the following day.