نوع مقاله : مقاله علمی پژوهشی
نویسندگان
1 دانشگاه تبریز
2 سازمان هواشناسی کشور
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Precipitation is one of the most important hydrological and climatic variables and plays a fundamental role in water resources management, flood forecasting, and hydrological process modeling. In many regions, the limited spatial distribution of rain-gauge stations has led to the use of satellite precipitation products as a complementary, and in some cases alternative, source of precipitation data. However, because of the complexity of precipitation processes and the influence of physiographic factors such as topography and climatic conditions, regional-scale evaluation of these products is essential. In this study, the performance of the GPM-IMERG Version 07 (Final Run) satellite precipitation product was evaluated over northwestern Iran using ground-based rain-gauge observations. The performance of GPM-IMERG was assessed at monthly and seasonal timescales using a set of continuous and categorical statistical indices. The results showed that GPM-IMERG tends to overestimate precipitation in most months of the year and has limitations in accurately reproducing observed precipitation amounts. Negative Nash-Sutcliffe efficiency (NSE) values during most periods indicate weak performance in simulating actual precipitation variability, while relatively high false alarm ratio (FAR) values and low probability of detection (POD), critical success index (CSI), and Heidke skill score (HSS) values indicate limited skill in correctly detecting precipitation events. Seasonal analysis further showed that the product performs better in autumn and winter than in other seasons. Overall, the findings of this study indicate that the direct use of GPM-IMERG in northwestern Iran for sensitive hydrological applications is subject to important limitations, and that bias correction, regional calibration, and integration with ground-based observations can play a significant role in improving the accuracy and reliability of this product for climatic and hydrological studies.
کلیدواژهها [English]
)