Mapping Changes in Global Irrigated Areas

The intensification of irrigated agriculture has increased global crop production but resulted in widespread stress to freshwater resources. Ensuring that increases in irrigated production only occur in places where water is relatively abundant is a key objective of sustainable agriculture, and knowledge of the evolving extent of irrigated land is important for crop modelling and water use management. Here we utilize the latest sub-national irrigation statistics from various official sources to develop a gridded global product of the area equipped for irrigation (AEI) for the years 2010 and 2015. Combining these outputs with existing maps of AEI available up to the year 2005, we then quantify changes in global irrigated areas since the start of the century. For instance, we find that in China, the total AEI increased from 66.74 million hectares in to 71.74 million hectares. For India and the United States, we observed an increase of 4% and 1.6% respectively. These updated maps will provide critical information for developing a new global database of crop-specific irrigated areas, a much needed resource in global Earth System simulations.