Water Use - Agricultural Water Withdrawal

Agriculture represents 70% of global water use. Yet, experience shows that the number of countries where agricultural water use is monitored with sufficient accuracy is limited. In most cases, gross irrigated areas are multiplied by an average unit water use to obtain an estimate of the country’s water use in irrigation.To estimate the pressure of irrigation on the available water resources, an assessment has to be made both of irrigation water requirements and of water withdrawal for agriculture. Precipitation provides part of the water crops need to satisfy their transpiration requirements.