Advances in Applied Agricultural Sciences 2 (2014); 12: 56-72
Irrigation status of Americas
Mohammad Valipour 1
1 Department of Water Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran.
The aim of this paper is to study agricultural water management in Americas between 1962 and 2011. For this purpose, all necessary information was gathered from Food and Agriculture Organization of the United Nations (FAO) and was checked using The World Bank Group (WBG). Among all presented data in the FAO database, 10 indexes were selected (due to more importance and more availability for all the countries in Americas). These indexes are permanent crops to cultivated area (%), rural population to total population (%), total economically active population in agriculture to total economically active population (%), human development index (HDI), national rainfall index (NRI) (mm/yr), value added to gross domestic product (GDP) by agriculture (%), irrigation water requirement (mm/yr), percent of total cultivated area drained (%), difference between NIR and irrigation water requirement (mm/yr), and area equipped for irrigation to cultivated area (%). These indexes were analyzed for all 36 countries in the study area and amount of area equipped for irrigation to cultivated area (10th index) was estimated by two different formulas and using the other 9 indexes. The results show relative error is less than 20 percent. In addition, an average index was calculated using two various methods for assessment of countries conditions for agricultural water management. Ability of irrigation and drainage systems was studied using other 8 indexes with more limited information. These indexes are surface irrigation (%), sprinkler irrigation (%), localized irrigation (%), spate irrigation (%), agricultural water withdrawal (10 km3/yr), conservation agriculture area as percent of cultivated area (%), percent of area equipped for irrigation salinized (%), and area waterlogged by irrigation (%). Finally, tendency of farmers to use of irrigation systems for cultivated crops has been presented.