## 6 Discussion
### Current State and Future Perspectives  
Iran's climate is dominated by arid and semi-arid climate zones, which are characterized by low precipitation and high evapotranspiration rates. The country has faced many climate hazards, such as drought and floods [65]. Meanwhile, the events are coupled with the over-abstraction of groundwater and over-reliance on non-renewable water sources that have escalated the water resource condition into crisis [116; 117]. Accordingly, to reduce and reverse the current water resource trend in Iran, in addition to effective legislation to stop aggressive water demands, having access to high-quality data, such as accurate precipitation estimates, is a prime need. In particular, the availability of reliable and long-term precipitation data allows for the better monitoring of water resource conditions and the adoption of more sophisticated strategies to mitigate the water crisis. The findings of this paper, on the whole, indicate that the current state of GPPs requires further modifications and enhancements to provide more precise and accurate estimates of precipitation over Iran. Although these GPPs have been widely employed globally, and also in Iran, more accurate GPPs are needed with respect to the current state of Iran. In fact, the more accurate GPPs allow the more accurate monitoring of relevant phenomena, such as drought, and managing water resources. Beyond the validation analyses in the present study, other scholars reported just satisfactory accuracies and flaws of GPPs across Iran and globally [35; 56; 57; 109; 118]. Although they have identified the best-performing GPP in their region, the common implications in the most relevant studies were the acceptable accuracy of GPPs, not the highly potential precipitation estimates overall. Therefore, thisis a critical need to enhance such GPPs for the entirety of Iran. The common practices may include applying the further regional (i.e., country/basin level) bias correction and calibration of a GPP, with potential performance, enhancing its capabilities, as with other regions [98]. An alternative solution could be to generate a precipitation platform, similar to the Canadian Precipitation Analysis [119], to combine all available data sources, GPPs and in situ data, and generate a unified and accurate GPP for Iran. This platform can have the sub-country level extension based on the precipitation rate, climate zones, or basins to develop the unified GPP with higher accuracy. This platform could provide high-quality precipitation data to help scholars conduct more accurate research and governors make informative decisions for water resource monitoring and management.  
Although Iran was considered the case study here, the aforementioned points are not only associated with Iran. Accordingly, other countries with a high demand for accurate precipitation datasets require such platforms to deepen their understanding of relevant phenomena and future forecasts [13]. There are currently several global and regional GPPs and platforms; nevertheless, the diversity of climates and other influential factors hamper the full potential of these GPPs for detailed regional or country-level studies [6]. Consequently, the generation of national precipitation platforms can be a prospective solution for a better understanding of precipitation patterns, promoting better water resource management, and achieving Sustainable Development Goals (SDGs). In the last point, these national platforms could be merged through international collaborations to make a consolidated precipitation platform that better fits the national, regional, and global scales.