The development of Atmospheric Crop Moisture Index for irrigated agriculture

Abstract

This paper develops the Atmospheric Crop Moisture Index (ACMI), an indicator of atmospheric drought. Levels in the index represent the possibility of rainfall or the lack of moisture needed at various stages of crop growth. The lack of moisture is determined with the ratio between water supply and demand, where the supply indicator is Precipitable Water Vapor (PWV). The ACMI was calculated from data collected between February 2010 and September 2014. The example of calculation of 10-day values of ACMI10 for rice is provided. The comparison of ACMI and other indices shows poor correlation with the SPI, the SPEI, and the scPDSI; however, it displays high correlation with precipitation, the PE, and the MAI. The ACMI is a parameter affected by surface temperature, relative humidity, wind speed, atmospheric pressure, and solar irradiation; all these parameters are included in the study of drought. The ACMI is an effective tool for agricultural water management.