Impact of Hourly Time Resolution on Hydrological Modeling of Ungauged Basins: A Systematic Review of Accuracy

Abstract

Flood risk management in ungauged basins faces critical limitations due to the scarcity of in-situ data and the inadequacy of daily records to capture the dynamics of extreme events. The main objective of this study was to evaluate, through a systematic review using the PRISMA methodology, the impact of hourly temporal resolution on the accuracy of hydrological models in ungauged basins compared to daily scales. Seventy scientific articles from Scopus, Web of Science, and ScienceDirect, published between 2010 and 2025, were analyzed. The results show that hourly resolution drastically reduces the uncertainty in estimating peak flows and time to peak, overcoming the systematic underestimation inherent in daily aggregation, a crucial factor for flash flood modeling. Furthermore, the integration of high-resolution satellite precipitation products with machine learning techniques and data fusion was identified as the most effective strategy to address the lack of information. It is concluded that the adoption of the time scale constitutes an indispensable paradigm shift for the development of robust early warning systems and the design of resilient infrastructures in the face of climate change.