Assessment of The Applicability of Remotely Sensed Rainfall Products for Hydrological Analysis in The Levant Region (Case Study: Historical Palestine)

The availability of precipitation data from in-situ stations faces various challenges including varying quality and resolutions, improper distribution, and scarcity in many regions. This is particularly true for the West Bank. Hence, identifying the best available alternatives is a priority since high quality precipitation estimates are essential for most hydrological applications. This study focuses on examining the suitability of four satellite precipitation products (IMERG Final Run, PDIR-Now, CCS-CDR, CMORPH) in the Levant region taking Historical Palestine (West Bank, Israel) a case study. These precipitation products were compared to 502 in-situ rainfall stations (132 Palestinian and 370 Israeli) across the region at a daily time-step and had fine spatial resolutions varying 4-10 Km. Results show that IMERG estimates outperform all other products, with a mean R² = 0.33 and Probability of Detection (POD) =0.7 with no adjustments applied. This R² value is significantly higher than those found in other studies with similar climates. CMORPH was found to be the next best with a mean R² =0.2 and POD = 0.4. The impact of elevations was also investigated and while IMERG was again the best overall, CCS-CDR performed better at lower elevations. Additionally, the satellite products were used to compare nearby Israeli and Palestinian stations and all satellites achieved higher results when compared to the Israeli stations. This potentially indicates the need for further investigation into the quality of Palestinian stations. Overall, this study found that IMERG provided the best performing satellite-based precipitation estimate for the Levant Region across a range of elevations, climatic regions, and rainfall thresholds. In addition to identifying the best performing date sets and examining newly released satellite products, this study’s finding will open the way to the application of these data sets for many hydrological purposes using available, easy-access remotely-sensed products.