Author(s): Myriam Benkirane; Nour-Eddine Laftouhi; Agustin Millares; Said Khabba
Linked Author(s): Myriam Benkirane
Keywords: Satellite-based data; TRMM; GPM; Flood modeling; Mediterranean High- Mountainous catchments; Lake of dat
Abstract: Ground-based observations are sparse and spatially irregular in the Mediterranean High mountainous catchments. These factors constitute real issues for water resources management. However, it is difficult to obtain accurate information on extreme rainfall from rain gauges in the mountainous areas of the Moroccan High Atlas. Satellite precipitation products (SPPs), Tropical Rainfall Measuring Mission (TRMM) and its successor, Global Precipitation Measurement (GPM), have provided highly acceptable spatial and temporal resolution datasets. This study proposes a framework for statistical and hydrological assessment of the TRMM 3B42V7 and GPM IMERG V6 (SPPs), at multi-temporal scales from 2014 to 2020. The rainfall and flow were obtained from the Taferiat station located at the outlet of the Zat basin, provided by the Tensift Hydraulic Basin Agency and meteorological data delivered from the Moroccan National Meteorological Agency. They are used as benchmark data. Several statistical methods were applied to assess the capability of the (SPPs) in estimating precipitation, assessing and comparing the performance of the selected products. The results indicate that: (1) both products showed low correlation with rain gauges at hourly and daily time steps and high correlation at monthly and annual time steps, the average Correlation Coefficient is 0. 75; (2) the IMERG V5 product detects more efficiently precipitation events at short time steps (hourly and daily), while the 3B42 V7 has a strong ability to detect precipitation events at large time steps (monthly and yearly; (3) the calibration and validation results are satisfactory. The Nash coefficients are very good, ranging from 62.5% to 90.5%; and (4) the most important point to remember is that the 3B42V7 product underestimates small rainfall events in a short time step. While, the IMERGV5 products has a good capacity to record small rainfall events, so it is recommended to use this product for flood modeling and forecasting in countries with similar climates or areas with sparse rain gauge networks.
DOI: https://doi.org/10.3850/IAHR-39WC2521711920221293
Year: 2022