**2. Methodology**

To answer the previous questions posed in Section 1.2, a systematic literature search using the two well-known databases Scopus and Engineering Village was conducted to check relevant studies. In the first stage, a group of pertinent keywords were identified and used to search databases using the title/abstract/keywords included in the papers. The first step required a filter, since the area of sustainability is extensive within the literature. Moreover, looking through a confined yet credible quantity for a literature review paper is crucial.

Therefore, the scope of this search was exclusive to peer-reviewed articles and peerreviewed conference papers. Additionally, the search had two conditions for all included documents: (a) documents should have been produced in the period from 2000 to 2021 and (b) documents should be written in the English language only. This period was selected because several frameworks for assessing the WRM system were produced after 2000. Furthermore, this is consistent with the method applied by other authors, such as Topal et al. [50]. This method uses a four-step clustering algorithm (i.e., Scope, Target Group, Subject Domain, and Methods) to narrow the research area. This narrowing process would mean excluding, to some degree, any unrelated studies by using the OR operator within each category's keywords and the AND operator within each cluster [50]. The idea of this process is straightforward, requiring all studies covered in this review to be included in the intersection area of all four clusters.

#### *2.1. Keyword Selection*

In the Scope cluster, many terms mainly related to sustainability and WRM were used to define the largest frame with which the search should start. These specific terms and their derivatives were "*#water resources management*", "*#water management*", "*#water shortage*", "*#water assessment*", "*#SWRM*", "*#sustainable assessment*", "*#sustainable measurement*", "*#water sustainable index*", "*#sustainability principles*", "*#sustainable development*".

The Target Group of this study concerned the primary sectors that received water or were affected by any decisions related to its supply and demand. The main terms used for the Target Group cluster were: "*domestic water*", "*municipal*", and "*stakeholder*".

The Subject Domain keywords were specific for the required method and its main parts that could evaluate the combination of the Scope and the Target Group and the geographic areas that needed to be investigated. The terms used in this search for these purposes were "*indicator*", "*indicator-based*", "*framework*", "*criteria*", "*index*", "*component*", "*arid*", and "*semi-arid*". It is worth mentioning that this category (i.e., Subject Domain) was used twice in the exact search. The first one included all required fields (i.e., Subject/Title/Abstract in the Engineering Village database, and Title/Abstract/Keywords in the Scopus database). The second one was only in the title, that is, one of the keywords needed to be in the article's title. This action was essential to reduce the enormous number of unrelated studies.

The fourth group, the methods of data collection or treatment based on the participatory approach, was assigned. The terms included in this cluster were "*survey*", "*interview*", "*questionnaire*", and "*participatory*".
