This application contains fall Residual Crop Residue Cover (RCRC) estimates for Whitman County, Washington. RCRC is estimated from remote sensing data.
The PalouseSAT's Residual Crop Residue Cover product provides percent cover estimates from 2013 to present (as data become available) for clear Landsat 8 scenes between September 1 and November 30.
The estimates were produced fitting a three parameter linear model to field data collected across Whitman County in 2021. The modeling used methods described by Jansen et al. 2018.
Several models were compared and the selected model balanced accuracy with complexity using normalized difference tillage index (NDTI), the near-infrared (NIR) band and the shortwave infrared 2 (SWIR2) band. Using the full 2021 dataset we an r2 of 0.47 and a relative RMSE of 29.2%. This model be continually improved as new data is collected.
Jansen, Vincent S., Crystal A. Kolden, and Heidi J. Schmalz. 2018. "The Development of Near Real-Time Biomass and Cover Estimates for Adaptive Rangeland Management Using Landsat 7 and Landsat 8 Surface Reflectance Products" Remote Sensing 10, no. 7: 1057. https://doi.org/10.3390/rs10071057
The normalized difference tillage index (NDTI) is used to estimate crop residue cover in agricultural fields and has been successful at identifying conservation tillage and conventional tillage (Van Deventer et al., 1997). This is achieved by measuring the brightness reflected off of crop residues post-harvest. An NDTI value of +1 would estimate full crop residue coverage (conservation tillage) and an NDTI value of -1 would indicate bare soil, urban areas or water. NDTI values closer to 0 estimate a mix of crop residue and soil. As crop residue starts to decay NDTI becomes a less effective measure of tillage practices because soil and crop residue are similar in color.
The normalized difference vegetation index (NDVI) is used to quantify the density of green vegetation cover on the Earth's surface. This is accomplished by measuring the difference between near-infrared wave light (which vegetation strongly reflects) and visible light (which vegetation absorbs). The values for the NDVI will range from -1 to 1. An NDVI value of -1 most likely indicates water on the landscape, and a NDVI value of +1 would suggest a dense canopy of green leaves. When NDVI is close to zero there is likely no green leaves and could identify urban areas or fallow crop ground. More information about NDVI