University of Tehran Journal of Range and Watershed Managment 5044-2008 75 2 2022 09 06 Evaluation of Spatial and Temporal Variability of the several datasets for precipitation over Iranian watersheds Evaluation of Spatial and Temporal Variability of the several datasets for precipitation over Iranian watersheds 181 196 88776 10.22059/jrwm.2021.281778.1386 FA Maryam Rostami PhD Graduate in Watershed Management, Faculty of Natural Resources, University of Tehran, Karaj, Iran Ali Salajegheh Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran Forood Sharifi Professor of Soil conservation and watershed management Research Institute, Tehran, Iran Arash Malekian Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran TAYYEBEH MESBAHZADEH Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran Journal Article 2019 05 20 Abstract<br /><br />Precipitation plays an important role in climatic, water, energy and biogeochemical cycles. Several global and regional data sets currently provide historical estimates of this variable over Iran, including the MWEP and WFDEI forcing datasets and production of some institutions such as MOHC, SMHI and IITM. All these datasets provide data with different resolutions based on gage stations, satellite Images and models output. In this study, we do an inter comparison between these data sets during 1990- 2008. We also validate all ten data sets against independent ground station observations over 30 second-order basins of Iran. MSWEP and WFDEI have an acceptable compatibility with observational data on different spatial and temporal resolutions. RMSE and Bias are 5.68, 6.34 and 0.58, 2.75 for these two datasets during 228 months, respectively. However, it is needed that MSWEP improves in the western and northwestern parts of the country and WFDEI in June and September months. Our findings in this research provide valuable guidance for a variety of stakeholders, including rainfall- runoff and land-surface modelers, watershed management studies and data providers. Abstract<br /><br />Precipitation plays an important role in climatic, water, energy and biogeochemical cycles. Several global and regional data sets currently provide historical estimates of this variable over Iran, including the MWEP and WFDEI forcing datasets and production of some institutions such as MOHC, SMHI and IITM. All these datasets provide data with different resolutions based on gage stations, satellite Images and models output. In this study, we do an inter comparison between these data sets during 1990- 2008. We also validate all ten data sets against independent ground station observations over 30 second-order basins of Iran. MSWEP and WFDEI have an acceptable compatibility with observational data on different spatial and temporal resolutions. RMSE and Bias are 5.68, 6.34 and 0.58, 2.75 for these two datasets during 228 months, respectively. However, it is needed that MSWEP improves in the western and northwestern parts of the country and WFDEI in June and September months. Our findings in this research provide valuable guidance for a variety of stakeholders, including rainfall- runoff and land-surface modelers, watershed management studies and data providers. https://jrwm.ut.ac.ir/article_88776_228b739c8f36f8e50d1f0aeb9527a475.pdf