# Inland Water Level Monitoring from Satellite Observations:
## 3 Review Results  
As described in the preceding chapter, the study selection process consists of four steps: (1) _identification_ of relevant scientific studies from the five literature databases, (2) _screening_ the abstracts of publications applying the relevant criteria, (3) _eligibility_ applying both the inclusion and exclusion criteria to the full papers, and finally (4) _inclusion_ re-applying criteria to the full papers [42]. For the first step, using the multiple keywords with the Boolean operators presented in Table 1, the number of published articles retrieved by the five electronic literature databases is 531. The current scoping paper refers to the period between 1 January 2018 and 31 December 2022. The number of publications was reduced to 386 by excluding the \"grey literature\". Another 136 documents were excluded by removing duplicates. Thus, the number of remaining documents for the title and abstract screening process is 250. Afterward, the Swift Review uses a definition of \"Relevant\" by considering a prioritization ranking score of 0.6 or higher. This Threshold of Relevance was empirically selected. As a result, the remaining documents are 72 and thus implementing the exclusion criteria during the full-text screening, a total number of 48 scientific articles were finally selected. The PRISMA flowchart [39], illustrated in Figure 2, depicts the different phases of the current scoping review paper and the number of selected publications at each stage of the process. Moreover, performing the priority ranking at the Swift Review, the ranking scores of the examined literature varied from 0.11 to 0.87. As can be seen in Figure 3, the ranking performance curve displays the percentage of the included documents (blue line) occurring in each quantile of the ranked list. Nearly 80% of the included documents occur in the top 30% of the ranked list and virtually all the included documents occur in the top 60% of the ranked list. In addition, documents at the top of 25% of the ranked list are included in the \"Relevant\" list. Also, the yellow line shows the baseline performance we should expect if the ranking score had been generated completely at random such that included publications were uniformly distributed in the ranked list, while the green line depicts the performance for items in the \"test set\". Finally, it can be understood that the ranking performance on the training documents will typically exceed the performance on the unlabeled document set. Also, as can be seen in Table 2, the confusion matrix as well as the sensitivity score shows that around 83% of the publications, with a prioritization score of 0.6 or higher, are included in the list of \"Relevant\" publications. The 48 scientific publications that were finally selected for the current scoping review paper are mainly published in seven scientific journals which are presented in Figure 4. Apart from the 33 scientific papers published in 7 scientific journals, a total number of 15 scientific journals appeared only once and are aggregated to the \"Other\" category. As can be seen, the majority of scientific publications (n = 12) have been published in Remote Sensing peer-reviewed open-access academic journals. Moreover, the other six scientific journals focus on environmental monitoring, and their research is mainly oriented toward Remote Sensing and Water (Journal of Hydrology | n = 5, Remote Sensing of Environment | n = 5, Advances in Space Research | n = 4, IEEE Transactions on Geoscience and Remote Sensing | n = 3, Hydrology and Earth System Sciences | n = 2, and Water | n = 2). Also, Figure 5 illustrates the number of publications per year between 2018 and 2022. As can be seen, the number of published articles in 2021 and 2022 was higher than the number of publications in 2019 and 2020, showing the increased interest in the water level monitoring over inland water bodies by spaceborne missions in the last two years.