# A Review of Irrigation Information Retrievals from Space and Their Utility for Users
## 5 The User Perspective: Observation Requirements and Current Obstacles  
From a practical point of view, it is still not evident whether irrigation information collected from satellite observations, models, and their combinations can help farmers, water managers, or basin authorities. Recent important contributions highlight that this information is paramount for an efficient water and agricultural management, especially over data-scarce regions [134]. Notable examples derive from irrigation monitoring systems platforms, for instance the WUEMOCA project developed by the University of Wuerzburg, Germany [135], or the FAO's portal to monitor Water Productivity through Open-access of Remotely sensed derived data (WaPOR), which promote the use of satellite data to help countries monitor agricultural water productivity, identify water productivity gaps, and find solutions [136].  
This section aims to understand the potential utility of EO-based irrigation information for users. To that end, we reviewed the answers of a survey that has been conducted with a set of ten users, representative of different Mediterranean countries (Ebro River basin in Spain, the South of France, Po River Valley and Sardinia, in Italy). We did not expect the users to have knowledge of remote sensing capabilities, but this was considered advantageous as we were interested in understanding their real needs and the potential utility of current and future satellite mission to satisfy these needs.  
This survey is not comprehensive and does not aim to picture farmer requirements worldwide, but aims at fostering the discussion on whether the satellite-based information on irrigation is mature enough to be used in a challenging area such as the Mediterranean region. Therefore, it must be interpreted only in a qualitative sense. Nevertheless, even though the discussion focuses on the Mediterranean, findings might likely be transferrable to other areas. A few limitations shall be noted upfront, however: The utility of remote sensing for irrigation monitoring and management might depend on many factors, such as the type of user and its responsibilities (basin authority, which manages a very large hydrological unit; irrigation district, which distributes water to the farmers; large farming enterprise, which may have access to modern technology to manage the farm; small farmer, with limited access to technology), the spatial organization of the irrigation fields (size of the fields, size of the properties, diversity or homogeneity of cropping patterns), the type of irrigation method (modernized or traditional, localized or extensive), the cost of water (price of water, price of energy, contribution to the maintenance of the infrastructure), etc. Thus, the requirements are very heterogeneous, and potential irrigation products must be able to provide information to a wide array of users with very different needs in terms of spatial resolution and temporal frequency, and latency of observations, type of information and variables, accuracy, and accessibility.  
In the following, we review each of these factors and discuss the answers provided by contacted users and organizations in relation to the ability of remote sensing observationsto track and detect irrigation. The used questionnaire, which is part of the Irrigation+ project funded by the European Space Agency (ESA) (See supplementary Material).