This book examines the relationship between irrigation and precipitation. The relationship is explored using the Palmer Drought Severity Index (PDSI) as a proxy for irrigation use, the Spatial Synoptic Classification (SSC) as a means of classifying surface air mass type, and the use of five atmospheric flow types characterizing the synoptic flow pattern. Scenarios, at each irrigated region, involving PDSI and either air mass type or flow type were tested using both parametric and non parametric procedures. This approach yields results according to flow type and air mass type at times when...