Agricultural Reference Index for Drought (ARID)
Index name: Agricultural Reference Index for Drought (ARID).
Ease of use: Red.
Origins: Based upon research done in the south-east United States by Woli at Mississippi State University and Jones et al. at the University of Florida in 2011.
Characteristics: Predicts the status of moisture availability in the soil. It uses a combination of water stress approximations and crop models to identify the impact of water stress on plant growth, development and yield for specific crops.
Input parameters: Daily temperature and precipitation. The CERES-Maize model is also used, but other crop simulations models can used.
Applications: Used for identifying and predicting drought in contexts where agricultural impacts are the primary concern.
Strengths: Crop models and water balance methods prove to be useful in predicting soil moisture and subsequent stress to crops. Can be computed daily so reaction times to drought will be quick.
Weaknesses: Designed and tested in the south-east United States for only a few cropping systems. Not easily transferable.
Resources: The equations used and the methodology are well explained in the referenced article below. No source code is publicly available.
Reference: Woli, P., J.W. Jones, K.T. Ingram and C.W. Fraisse, 2012: Agricultural Reference Index for Drought (ARID). Agronomy Journal, 104: 287–300.