In this paper, irrigated agriculture has been estimated in Asia Pacific using three different scenarios by 2035 and 2060. The number of 10 indices (as the main indices) was selected to assess agricultural water management based on their importance and other indices were not studied due to lack of adequate data. These indices are permanent crops per cultivated area, rural population per total population, total economically active population in agriculture per total economically active population, human development index (HDI), value added to gross domestic product (GDP) by agriculture, national rainfall index (NRI), irrigation water requirement, difference between NRI and irrigation water requirement, percent of total cultivated area drained, and irrigated agriculture per cultivated area. The changes of the main indices in the previous half of century indicated that they had similar values in some regions and had very different values in other regions due to the nature of the indices and conditions of the regions. In the first step, the author studied variations of the main indices during the previous half of the century using linear regression and R2 value then amount of each index was estimated in 2035 and 2060 by obtained equations and three different scenarios. The results show that trends of permanent crops per cultivated area (with the exception of Caucasus, Maritime Southeast Asia, and Oceania), HDI, irrigation water requirement, and percent of total cultivated area drained are increasing and trends of rural population per total population, total economically active population in agriculture per total economically active population, value added to GDP by agriculture, and difference between NRI and irrigation water requirement (with the exception of East Asia Pacific) are decreasing. The maximum value of irrigated agriculture is related to Central Asia; 69.2% and 81.8% by 2035 and 2060, respectively.
