*4.3. Application Scale*

Another vital element of the indicator-based assessment framework that needs to be carefully dealt with is the application scale. The scales assigned in the literature for SWRM indices in descending order are usually global, territorial (or regional), local, and community scales, in addition to river basins. Indeed, it is important to understand that the application of each scale might require different criteria and specific guidelines for the selection process of indicators that would form a suitable framework. For example, the Water Poverty Index (WPI) [67] (see Section 5.1) has two different versions/values of the same indicator because of the scale change. In other words, the original version was on a global scale with specific indicators of commonly available data among countries that can serve for this scale [67], while the second version was on a community scale, adding and removing some indicators to fit with the requirements of the case studies [70]. Therefore, knowing the appropriate application scale is essential.
