Hidden issues and challenges of the concept and use of water productivity index

The water productivity index (WP), which is defined as the crop produced per unit of consumed water, has been considered as a key indicator for the optimal use of water in the agricultural sector. It has been heavily relied upon in the Iran's agricultural water policies and plans. However despite several years have passed since the introduction of this concept and index, unfortunately, water crisis still exists and is expanding in the country and measures to increase WP in agricultural products have not yet been able to effectively solve the country's water issues. In this review-analytical paper, the issues and challenges of using this index in practice have been discussed and the shortcomings, challenges, measures, and infrastructure necessary for the proper use of this index have been discussed and analyzed. According to the results, there are hidden issues and challenges (in 8 groups) in its application. The most important of which are the need to deeply understand the concept and definition of WP in the country's expert and management community, and the problems and issues of using the index from the aspect of lack of the required infrastructure for the proper impacts of improving WP in mitigating water scarcity. According to the identified issues and challenges, it was concluded that improving WP could not be a sole measure to solve the country's water crisis, because it fulfills just initial conditions. In order to fulfill conditions sufficiently and to implement related comprehensive measures and interventions, the necessary hardware, software, legal, and policy infrastructures must be provided.