Preparations of Input Data for EPIC/APEX

[TX H.]

Hi,

EPIC/APEX (as well as other process-based models) usually need a lot of detailed input data for users' research sites (or areas). Preparations of such data could be an obstacle for wide application of such models. Are there examples of procedures for preparing these inputs data with public datasets in the US? 

Thanks! 

 

[Jaehak]

Great question. Both WinAPEX and ArcAPEX programs provide extensive databases for the entire U.S. regarding soil properties, crop parameters, daily weather, and agricultural management practices. Aside from these default data sets, you can use a GIS tool to determine land slopes based on DEM, the Cropland Data Layer (CDL) to build crop rotations or weather data from your local weather stations. Web soil survey is a useful tool to accurately characterize soil properties. Remote sensing data can provide other info such as time series surface residue amounts or evapotranspiration rates as input to the model. The book entitled Conservation Practice Modeling Guide for SWAT and APEX" by Waidler et al, 2011 and the APEX model parameterization manual by Steglich et al, 2016 are both excellent resources for APEX users. 

The APEX workshop program offers basic and advanced skill sets to build APEX input files using these resources. Unfortunately, our annual APEX workshop program has been suspended since 2020 when the covid pandemic hit the country. We hope to resume our APEX/EPIC training program soon in the next year.